[ { "id": "authors:6ack4-kbf20", "collection": "authors", "collection_id": "6ack4-kbf20", "cite_using_url": "https://authors.library.caltech.edu/records/6ack4-kbf20", "type": "article", "title": "Black Hole Spin Measurements from X-Ray Reflection Spectroscopy: Quality Criteria and Community Recommendations", "author": [ { "family_name": "Garcia", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Connors", "given_name": "Riley" }, { "family_name": "Brenneman", "given_name": "Laura W.", "orcid": "0000-0003-2663-1954" }, { "family_name": "Steiner", "given_name": "James F.", "orcid": "0000-0002-5872-6061" } ], "abstract": "X-ray reflection spectroscopy provides one of the most effective electromagnetic routes to measuring the dimensionless spin parameter of accreting black holes. The method has produced spin constraints for both stellar-mass black holes in X-ray binaries and supermassive black holes in active galactic nuclei, and it is central to the science objectives of present and future X-ray telescopes. At the same time, this method is vulnerable to a set of coupled observational and modeling systematics: continuum-reflection degeneracy, insufficient passband, unresolved distant reflection or absorption, detector effects, source variability, accretion-state dependence, and assumptions built into the reflection model itself. This article synthesizes the talks and discussions held at the 2025 Wake Forest workshop Recent Progress on Black Hole Spin Measurements Across the Electromagnetic and Gravitational Spectra; motivated by them, we propose a practical quality-control framework for assessing whether a published reflection-based spin measurement should be treated as robust, provisional, or not assessable from the published information alone. We organize the problem around three pillars: detectability, meaning that the relativistic reflection signal is unambiguously present in the data; uniqueness, meaning that the relativistic component can be separated from the continuum, from distant reflection, absorption, and instrumental effects; and robustness, meaning that the inferred spin is stable against plausible changes in model assumptions, data selection, and accretion-state treatment. We then translate these principles into applicable criteria, a tiered quality-classification scheme, and a reporting checklist for future analyses. The quantitative calibration of each criterion requires a dedicated campaign of simulations over realistic scenarios, which we outline here and defer to a future publication. We aim to define a reproducible path toward a curated, community-maintained compilation of reliable spin constraints and to guide the implementation of reflection spectroscopy in the high-throughput, high-resolution era.", "doi": "10.3390/galaxies14040071", "issn": "2075-4434", "publisher": "MDPI AG", "publication": "Galaxies", "publication_date": "2026-07-21", "series_number": "4", "volume": "14", "issue": "4", "pages": "71" }, { "id": "authors:pvgqe-5qf85", "collection": "authors", "collection_id": "pvgqe-5qf85", "cite_using_url": "https://authors.library.caltech.edu/records/pvgqe-5qf85", "type": "article", "title": "The 0.9 Ms XRISM/Resolve Spectrum of the Seyfert 1 Active Galactic Nucleus NGC 4151", "author": [ { "family_name": "Miller", "given_name": "Jon M.", "orcid": "0000-0003-2869-7682" }, { "family_name": "Xiang", "given_name": "Xin", "orcid": "0000-0002-7129-4654" }, { "family_name": "Mehdipour", "given_name": "Missagh", "orcid": "0000-0002-4992-4664" }, { "family_name": "Gu", "given_name": "Liyi", "orcid": "0000-0001-9911-7038" }, { "family_name": "Behar", "given_name": "Ehud", "orcid": "0000-0001-9735-4873" }, { "family_name": "Brenneman", "given_name": "Laura", "orcid": "0000-0003-2663-1954" }, { "family_name": "Byun \ubcc0", "given_name": "Doyee \ub3c4\uc758", "orcid": "0000-0002-3687-6552" }, { "family_name": "Costantini", "given_name": "Elisa", "orcid": "0000-0001-8470-749X" }, { "family_name": "Gallo", "given_name": "Luigi", "orcid": "0009-0006-4968-7108" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Guainazzi", "given_name": "Matteo", "orcid": "0000-0002-1094-3147" }, { "family_name": "Kosec", "given_name": "Peter", "orcid": "0000-0003-4511-8427" }, { "family_name": "Minezaki", "given_name": "Takeo", "orcid": "0000-0002-2933-048X" }, { "family_name": "Miura", "given_name": "Daiki", "orcid": "0009-0009-0439-1866" }, { "family_name": "Paltani", "given_name": "Stephane", "orcid": "0000-0002-8108-9179" }, { "family_name": "Zoghbi", "given_name": "Abderahmen", "orcid": "0000-0002-0572-9613" } ], "abstract": "

NGC 4151 is the brightest Seyfert 1 galaxy in the band of the Resolve calorimeter aboard XRISM. It has been observed on 14 occasions. Herein, we report on an analysis of its time-averaged 893 ks spectrum. The narrow Fe K α emission-line complex requires contributions from the torus and optical broad-line region (BLR). Models assuming an emissivity index of q = 2 for these components are statistically preferred, consistent with a \"bowl\" geometry for the central engine. A smooth red wing of these line components is consistent with Compton scattering from bound electrons, signaling the presence of dust in the base of the BLR and in the torus. The data statistically prefer relativistic reflection from a disk with an inner radius of r = 3.2(−2.0)^(+3.5) GM/c², and an inclination of θ = 29.7_(−0.4)^(+0.5) degrees. The Fe K edge at 7.1 keV is best modeled with contributions from multiple charge states, consistent with cool, kT  \u2243 5 eV collisional gas or photoionized gas. Slow \"warm absorber\" winds spanning Fe XX–XXVI , faster winds seen via Fe XXV and Fe XXVI lines, and ultra-fast outflows (UFOs) are detected simultaneously. The warm absorbers are \"failed\" winds; the data constrain their radius, density, filling factor, and distribution. For the most conservative volume filling factors, the UFOs may not be able to halt star formation. However, the UFOs may generate galaxy-altering feedback for larger filling factors and/or during certain intervals.

", "doi": "10.3847/2041-8213/ae63cd", "issn": "2041-8205", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal Letters", "publication_date": "2026-06-01", "series_number": "2", "volume": "1003", "issue": "2", "pages": "L34" }, { "id": "authors:z63xj-vka05", "collection": "authors", "collection_id": "z63xj-vka05", "cite_using_url": "https://authors.library.caltech.edu/records/z63xj-vka05", "type": "article", "title": "High-spectral-resolution X-Ray Observations of the Evolved Supermassive Stellar Binary System \u03b7 Carinae: Fe K\u03b1 Band Profile Revealed with XRISM", "author": [ { "family_name": "Audard", "given_name": "Marc", "orcid": "0000-0003-4721-034X" }, { "family_name": "Awaki", "given_name": "Hisamitsu" }, { "family_name": "Ballhausen", "given_name": "Ralf", "orcid": "0000-0002-1118-8470" }, { "family_name": "Bamba", "given_name": "Aya", "orcid": "0000-0003-0890-4920" }, { "family_name": "Behar", "given_name": "Ehud", "orcid": "0000-0001-9735-4873" }, { "family_name": "Boissay-Malaquin", "given_name": "Rozenn", "orcid": "0000-0003-2704-599X" }, { "family_name": "Brenneman", "given_name": "Laura", "orcid": "0000-0003-2663-1954" }, { "family_name": "Brown", "given_name": "Gregory V.", "orcid": "0000-0001-6338-9445" }, { "family_name": "Corcoran", "given_name": "Michael F.", "orcid": "0000-0002-7762-3172" }, { "family_name": "Corrales", "given_name": "Lia", "orcid": "0000-0002-5466-3817" }, { "family_name": "Costantini", "given_name": "Elisa", "orcid": "0000-0001-8470-749X" }, { "family_name": "Cumbee", "given_name": "Renata", "orcid": "0000-0001-9894-295X" }, { "family_name": "Diaz Trigo", "given_name": "Maria", "orcid": "0000-0001-7796-4279" }, { "family_name": "Done", "given_name": "Chris", "orcid": "0000-0002-1065-7239" }, { "family_name": "Dotani", "given_name": "Tadayasu" }, { "family_name": "Ebisawa", "given_name": "Ken", "orcid": "0000-0002-5352-7178" }, { "family_name": "Eckart", "given_name": "Megan E.", "orcid": "0000-0003-3894-5889" }, { "family_name": "Eckert", "given_name": "Dominique", "orcid": "0000-0001-7917-3892" }, { "family_name": "Eguchi", "given_name": "Satoshi", "orcid": "0000-0003-2814-9336" }, { "family_name": "Enoto", "given_name": "Teruaki", "orcid": "0000-0003-1244-3100" }, { "family_name": "Ezoe", "given_name": "Yuichiro" }, { "family_name": "Foster", "given_name": "Adam", "orcid": "0000-0003-3462-8886" }, { "family_name": "Fujimoto", "given_name": "Ryuichi", "orcid": "0000-0002-2374-7073" }, { "family_name": "Fujita", "given_name": "Yutaka", "orcid": "0000-0003-0058-9719" }, { "family_name": "Fukazawa", "given_name": "Yasushi", "orcid": "0000-0002-0921-8837" }, { "family_name": "Fukushima", "given_name": "Kotaro", "orcid": "0000-0001-8055-7113" }, { "family_name": "Furuzawa", "given_name": "Akihiro" }, { "family_name": "Gallo", "given_name": "Luigi", "orcid": "0009-0006-4968-7108" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Goto", "given_name": "Emi" }, { "family_name": "Gu", "given_name": "Liyi", "orcid": "0000-0001-9911-7038" }, { "family_name": "Guainazzi", "given_name": "Matteo", "orcid": "0000-0002-1094-3147" }, { "family_name": "Hagino", "given_name": "Kouichi", "orcid": "0000-0003-4235-5304" }, { "family_name": "Hamaguchi", "given_name": "Kenji", "orcid": "0000-0001-7515-2779" }, { "family_name": "Hatsukade", "given_name": "Isamu", "orcid": "0000-0003-3518-3049" }, { "family_name": "Hayashi", "given_name": "Katsuhiro", "orcid": "0000-0001-6922-6583" }, { "family_name": "Hayashi", "given_name": "Takayuki", "orcid": "0000-0001-6665-2499" }, { "family_name": "Hell", "given_name": "Natalie", "orcid": "0000-0003-3057-1536" }, { "family_name": "Hodges-Kluck", "given_name": "Edmund", "orcid": "0000-0002-2397-206X" }, { "family_name": "Hornschemeier", "given_name": "Ann", "orcid": "0000-0001-8667-2681" }, { "family_name": "Ichinohe", "given_name": "Yuto", "orcid": "0000-0002-6102-1441" }, { "family_name": "Inoue", "given_name": "Shun" }, { "family_name": "Ishi", "given_name": "Daiki" }, { "family_name": "Ishida", "given_name": "Manabu" }, { "family_name": "Ishihara", "given_name": "Yukiko" }, { "family_name": "Ishikawa", "given_name": "Kumi" }, { "family_name": "Ishisaki", "given_name": "Yoshitaka" }, { "family_name": "Junqueira", "given_name": "Francisco" }, { "family_name": "Kaastra", "given_name": "Jelle", "orcid": "0000-0001-5540-2822" }, { "family_name": "Kallman", "given_name": "Timothy" }, { "family_name": "Kanemaru", "given_name": "Yoshiaki", "orcid": "0000-0002-4541-1044" }, { "family_name": "Kara", "given_name": "Erin", "orcid": "0000-0003-0172-0854" }, { "family_name": "Katsuda", "given_name": "Satoru", "orcid": "0000-0002-1104-7205" }, { "family_name": "Kelley", "given_name": "Richard L.", "orcid": "0009-0007-2283-3336" }, { "family_name": "Kilbourne", "given_name": "Caroline A.", "orcid": "0000-0001-9464-4103" }, { "family_name": "Kitamoto", "given_name": "Shunji", "orcid": "0000-0001-8948-7983" }, { "family_name": "Kobayashi", "given_name": "Shogo", "orcid": "0000-0001-7773-9266" }, { "family_name": "Kohmura", "given_name": "Takayoshi" }, { "family_name": "Kubota", "given_name": "Aya" }, { "family_name": "Leutenegger", "given_name": "Maurice", "orcid": "0000-0002-3331-7595" }, { "family_name": "Loewenstein", "given_name": "Michael", "orcid": "0000-0002-1661-4029" }, { "family_name": "Maeda", "given_name": "Yoshitomo", "orcid": "0000-0002-9099-5755" }, { "family_name": "Markevitch", "given_name": "Maxim", "orcid": "0000-0003-0144-4052" }, { "family_name": "Matsumoto", "given_name": "Hironori" }, { "family_name": "Matsushita", "given_name": "Kyoko", "orcid": "0000-0003-2907-0902" }, { "family_name": "McCammon", "given_name": "Dan", "orcid": "0000-0001-5170-4567" }, { "family_name": "McNamara", "given_name": "Brian" }, { "family_name": "Mernier", "given_name": "Fran\u00e7ois", "orcid": "0000-0002-7031-4772" }, { "family_name": "Vander Meulen", "given_name": "Bert", "orcid": "0000-0002-5488-1961" }, { "family_name": "Miller", "given_name": "Eric D.", "orcid": "0000-0002-3031-2326" }, { "family_name": "Miller", "given_name": "Jon M.", "orcid": "0000-0003-2869-7682" }, { "family_name": "Mitsuishi", "given_name": "Ikuyuki", "orcid": "0000-0002-9901-233X" }, { "family_name": "Miyamoto", "given_name": "Asca" }, { "family_name": "Mizumoto", "given_name": "Misaki", "orcid": "0000-0003-2161-0361" }, { "family_name": "Mizuno", "given_name": "Tsunefumi", "orcid": "0000-0001-7263-0296" }, { "family_name": "Mori", "given_name": "Koji", "orcid": "0000-0002-0018-0369" }, { "family_name": "Mukai", "given_name": "Koji", "orcid": "0000-0002-8286-8094" }, { "family_name": "Murakami", "given_name": "Hiroshi" }, { "family_name": "Mushotzky", "given_name": "Richard", "orcid": "0000-0002-7962-5446" }, { "family_name": "Nakajima", "given_name": "Hiroshi", "orcid": "0000-0001-6988-3938" }, { "family_name": "Nakazawa", "given_name": "Kazuhiro", "orcid": "0000-0003-2930-350X" }, { "family_name": "Ness", "given_name": "Jan-Uwe" }, { "family_name": "Nobukawa", "given_name": "Kumiko", "orcid": "0000-0002-0726-7862" }, { "family_name": "Nobukawa", "given_name": "Masayoshi", "orcid": "0000-0003-1130-5363" }, { "family_name": "Noda", "given_name": "Hirofumi", "orcid": "0000-0001-6020-517X" }, { "family_name": "Odaka", "given_name": "Hirokazu" }, { "family_name": "Ogawa", "given_name": "Shoji", "orcid": "0000-0002-5701-0811" }, { "family_name": "Ogorza\u0142ek", "given_name": "Anna", "orcid": "0000-0003-4504-2557" }, { "family_name": "Okajima", "given_name": "Takashi", "orcid": "0000-0002-6054-3432" }, { "family_name": "Ota", "given_name": "Naomi", "orcid": "0000-0002-2784-3652" }, { "family_name": "Paltani", "given_name": "Stephane", "orcid": "0000-0002-8108-9179" }, { "family_name": "Petre", "given_name": "Robert", "orcid": "0000-0003-3850-2041" }, { "family_name": "Plucinsky", "given_name": "Paul", "orcid": "0000-0003-1415-5823" }, { "family_name": "Porter", "given_name": "Frederick S.", "orcid": "0000-0002-6374-1119" }, { "family_name": "Pottschmidt", "given_name": "Katja", "orcid": "0000-0002-4656-6881" }, { "family_name": "Sato", "given_name": "Kosuke" }, { "family_name": "Sato", "given_name": "Toshiki" }, { "family_name": "Sawada", "given_name": "Makoto", "orcid": "0000-0003-2008-6887" }, { "family_name": "Seta", "given_name": "Hiromi" }, { "family_name": "Shidatsu", "given_name": "Megumi", "orcid": "0000-0001-8195-6546" }, { "family_name": "Simionescu", "given_name": "Aurora", "orcid": "0000-0002-9714-3862" }, { "family_name": "Smith", "given_name": "Randall", "orcid": "0000-0003-4284-4167" }, { "family_name": "Suzuki", "given_name": "Hiromasa", "orcid": "0000-0002-8152-6172" }, { "family_name": "Szymkowiak", "given_name": "Andrew", "orcid": "0000-0002-4974-687X" }, { "family_name": "Takahashi", "given_name": "Hiromitsu", "orcid": "0000-0001-6314-5897" }, { "family_name": "Takeo", "given_name": "Mai" }, { "family_name": "Tamagawa", "given_name": "Toru" }, { "family_name": "Tamura", "given_name": "Keisuke" }, { "family_name": "Tanaka", "given_name": "Takaaki", "orcid": "0000-0002-4383-0368" }, { "family_name": "Tanimoto", "given_name": "Atsushi", "orcid": "0000-0002-0114-5581" }, { "family_name": "Tashiro", "given_name": "Makoto", "orcid": "0000-0002-5097-1257" }, { "family_name": "Terada", "given_name": "Yukikatsu", "orcid": "0000-0002-2359-1857" }, { "family_name": "Terashima", "given_name": "Yuichi", "orcid": "0000-0003-1780-5481" }, { "family_name": "Tsuboi", "given_name": "Yohko", "orcid": "0000-0001-9943-0024" }, { "family_name": "Tsujimoto", "given_name": "Masahiro", "orcid": "0000-0002-9184-5556" }, { "family_name": "Tsunemi", "given_name": "Hiroshi" }, { "family_name": "Tsuru", "given_name": "Takeshi", "orcid": "0000-0002-5504-4903" }, { "family_name": "T\u00fcmer", "given_name": "Ay\u015feg\u00fcl", "orcid": "0000-0002-3132-8776" }, { "family_name": "Uchida", "given_name": "Hiroyuki", "orcid": "0000-0003-1518-2188" }, { "family_name": "Uchida", "given_name": "Nagomi", "orcid": "0000-0002-5641-745X" }, { "family_name": "Uchida", "given_name": "Yuusuke", "orcid": "0000-0002-7962-4136" }, { "family_name": "Uchiyama", "given_name": "Hideki", "orcid": "0000-0003-4580-4021" }, { "family_name": "Ueda", "given_name": "Shutaro", "orcid": "0000-0001-6252-7922" }, { "family_name": "Ueda", "given_name": "Yoshihiro", "orcid": "0000-0001-7821-6715" }, { "family_name": "Uno", "given_name": "Shinichiro" }, { "family_name": "Vink", "given_name": "Jacco", "orcid": "0000-0002-4708-4219" }, { "family_name": "Watanabe", "given_name": "Shin", "orcid": "0000-0003-0441-7404" }, { "family_name": "Williams", "given_name": "Brian J.", "orcid": "0000-0003-2063-381X" }, { "family_name": "Yamada", "given_name": "Satoshi", "orcid": "0000-0002-9754-3081" }, { "family_name": "Yamada", "given_name": "Shinya", "orcid": "0000-0003-4808-893X" }, { "family_name": "Yamaguchi", "given_name": "Hiroya", "orcid": "0000-0002-5092-6085" }, { "family_name": "Yamaoka", "given_name": "Kazutaka", "orcid": "0000-0003-3841-0980" }, { "family_name": "Yamasaki", "given_name": "Noriko", "orcid": "0000-0003-4885-5537" }, { "family_name": "Yamauchi", "given_name": "Makoto", "orcid": "0000-0003-1100-1423" }, { "family_name": "Yamauchi", "given_name": "Shigeo" }, { "family_name": "Yaqoob", "given_name": "Tahir" }, { "family_name": "Yoneyama", "given_name": "Tomokage" }, { "family_name": "Yoshida", "given_name": "Tessei" }, { "family_name": "Yukita", "given_name": "Mihoko", "orcid": "0000-0001-6366-3459" }, { "family_name": "Zhuravleva", "given_name": "Irina", "orcid": "0000-0001-7630-8085" }, { "literal": "XRISM Collaboration" } ], "abstract": "
\n

The supermassive binary system, η Carinae, is experiencing enormous wind-driven mass loss at a rate unparalleled in the rest of the Galaxy. Their wind–wind collision (WWC) continuously produces shock heated, X-ray-emitting plasmas. The XRISM X-ray observatory observed the system in 2023 and 2024 when the X-ray emission began to increase toward periastron passage in 2025. This paper reports unprecedentedly high-resolution X-ray spectra in the Fe Kα band between 6.2 and 7.1 keV, obtained with the Resolve X-ray microcalorimeter. The hydrogen-like (Lyα) and helium-like (Heα) lines reveal three velocity components. Two of them are broadened with maximum velocities of 2000–3000 km s−1, likely originating from the postshock companion wind. The other is relatively narrow, with a Gaussian broadening of only ∼290 km s−1 in 1σ, which may originate from the postshock companion wind at the WWC stagnation point or penetrating the primary wind. The Fe fluorescent lines exhibit a moderate blueshift and broadening with velocities at 100–200 km s−1, consistent with the primary wind’s velocity field. The spectra also confirm a Compton shoulder of the Heα line complex for the first time. Both fluorescing and scattering spectral profiles indicate that the binary system is seen from the companion side during these observations. The flux ratio of the Compton-scattering emission to the fluorescent line suggests substantial hydrogen depletion of the primary wind, expected from CNO-cycled hydrogen nuclear fusion gas.

\n
", "doi": "10.3847/1538-4357/ae3a80", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2026-06-01", "series_number": "2", "volume": "1003", "issue": "2", "pages": "156" }, { "id": "authors:ex9a8-5ak48", "collection": "authors", "collection_id": "ex9a8-5ak48", "cite_using_url": "https://authors.library.caltech.edu/records/ex9a8-5ak48", "type": "article", "title": "Transient Relativistic Iron Emission Line from an X-Ray Flaring Supermassive Black Hole", "author": [ { "family_name": "Zhao", "given_name": "Xiurui", "orcid": "0000-0002-7791-3671", "clpid": "Zhao-Xiurui" }, { "family_name": "Ajello", "given_name": "Marco", "orcid": "0000-0002-6584-1703" }, { "family_name": "Civano", "given_name": "Francesca", "orcid": "0000-0002-2115-1137" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Kammoun", "given_name": "Elias", "orcid": "0000-0002-0273-218X", "clpid": "Kammoun-Elias" }, { "family_name": "Marchesi", "given_name": "Stefano", "orcid": "0000-0001-5544-0749" }, { "family_name": "Shen", "given_name": "Yue", "orcid": "0000-0003-1659-7035" }, { "family_name": "Stern", "given_name": "Daniel", "orcid": "0000-0003-2686-9241", "clpid": "Stern-D" }, { "family_name": "Yang", "given_name": "Qian", "orcid": "0000-0002-6893-3742" }, { "family_name": "Boorman", "given_name": "Peter G.", "orcid": "0000-0001-9379-4716", "clpid": "Boorman-Peter-G" }, { "family_name": "Harrison", "given_name": "Fiona", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" }, { "family_name": "Kara", "given_name": "Erin", "orcid": "0000-0003-0172-0854" }, { "family_name": "Pizzetti", "given_name": "Andrealuna", "orcid": "0000-0001-6412-2312" }, { "family_name": "Silver", "given_name": "Ross", "orcid": "0000-0001-6564-0517" }, { "family_name": "Sokolovsky", "given_name": "Kirill V.", "orcid": "0000-0001-5991-6863" }, { "family_name": "Stone", "given_name": "Zachary", "orcid": "0000-0002-8501-3518" }, { "family_name": "Torres-Alb\u00e0", "given_name": "Nuria", "orcid": "0000-0003-3638-8943" }, { "family_name": "Wu", "given_name": "Qiaoya", "orcid": "0000-0003-4202-1232" }, { "family_name": "Zhu", "given_name": "Peixin", "orcid": "0000-0002-1333-147X" } ], "abstract": "
\n

We report the discovery of the first transient relativistic iron Kα line in an active galactic nucleus (AGN), J1047+5907. The line was detected 21.5 days (rest frame) after an X-ray coronal flare was observed in 2008, and it exhibits significant broadening consistent with relativistic reflection from the accretion disk in the vicinity of the central supermassive black hole (SMBH). The line has a width of ∼300 eV, corresponding to a Keplerian velocity of 14,000 km s−1, at a distance of 5–41 light-days from the SMBH, strongly implying that the observed coronal flare triggered the emergence of the line. This event provides rare direct evidence of the response of the accretion disk to impulsive coronal illumination and offers a new method to probe the SMBH and disk physics. The relativistic modeling favors a broadened line produced by distant reflection from an accretion disk around a rapidly spinning black hole viewed at an intermediate inclination, consistent with other observations. Systematic monitoring of type 1 AGN following strong X-ray flares may open a new observational window into the innermost regions of AGN, enabling constraints on the physics of SMBH and its accretion disk at different radii that are otherwise challenging to access.

\n
", "doi": "10.3847/1538-4357/ae4482", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2026-03-20", "series_number": "1", "volume": "1000", "issue": "1", "pages": "28" }, { "id": "authors:txkc7-wz840", "collection": "authors", "collection_id": "txkc7-wz840", "cite_using_url": "https://authors.library.caltech.edu/records/txkc7-wz840", "type": "article", "title": "XRISM Finds the Changing-look Active Galactic Nucleus NGC 1365 in an Extended Low State: A Dense, Highly Ionized Outflow Obscures the Central Source", "author": [ { "family_name": "Zaidouni", "given_name": "Fatima", "orcid": "0000-0003-0931-0868" }, { "family_name": "Kara", "given_name": "Erin", "orcid": "0000-0003-0172-0854" }, { "family_name": "Kosec", "given_name": "Peter", "orcid": "0000-0003-4511-8427" }, { "family_name": "Behar", "given_name": "Ehud", "orcid": "0000-0001-9735-4873" }, { "family_name": "Mushotzky", "given_name": "Richard", "orcid": "0000-0002-7962-5446" }, { "family_name": "Koss", "given_name": "Michael", "orcid": "0000-0002-7998-9581" }, { "family_name": "Jur\u00e1\u0148ov\u00e1", "given_name": "A.", "orcid": "0000-0002-7292-6852" }, { "family_name": "Kammoun", "given_name": "Elias", "orcid": "0000-0002-0273-218X", "clpid": "Kammoun-Elias" }, { "family_name": "Brenneman", "given_name": "Laura W.", "orcid": "0000-0003-2663-1954" }, { "family_name": "Chakraborty", "given_name": "Joheen", "orcid": "0000-0002-0568-6000" }, { "family_name": "Ebisawa", "given_name": "Ken", "orcid": "0000-0002-5352-7178" }, { "family_name": "Eckart", "given_name": "Megan E.", "orcid": "0000-0003-3894-5889" }, { "family_name": "Fabian", "given_name": "Andrew C.", "orcid": "0000-0002-9378-4072" }, { "family_name": "Fukazawa", "given_name": "Yasushi", "orcid": "0000-0002-0921-8837" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Gu", "given_name": "Liyi", "orcid": "0000-0001-9911-7038" }, { "family_name": "Masterson", "given_name": "Megan", "orcid": "0000-0003-4127-0739" }, { "family_name": "Ogawa", "given_name": "Shoji", "orcid": "0000-0002-5701-0811" }, { "family_name": "Okajima", "given_name": "Takashi", "orcid": "0000-0002-6054-3432" }, { "family_name": "Paltani", "given_name": "St\u00e9phane", "orcid": "0000-0002-8108-9179" }, { "family_name": "Rogantini", "given_name": "Daniele", "orcid": "0000-0002-5359-9497" }, { "family_name": "Terashima", "given_name": "Yuichi", "orcid": "0000-0003-1780-5481" }, { "family_name": "Williams", "given_name": "Brian J.", "orcid": "0000-0003-2063-381X" }, { "family_name": "Yamada", "given_name": "Satoshi", "orcid": "0000-0002-9754-3081" } ], "abstract": "
\n

We present the first XRISM/Resolve observations of the active galactic nucleus NGC 1365, obtained in 2024 February and July. NGC 1365 is known for rapid transitions between Compton-thick and Compton-thin states, along with strong absorption from a highly ionized wind. During our observations, the source was found in a persistent low-flux state, characterized by a decrease in hard-X-ray luminosity and significant line-of-sight obscuration. In this state, XRISM/Resolve reveals clear Fe xxv and Fe xxvi absorption lines together with, for the first time in this source, corresponding emission lines. These features may arise either from reemission from a photoionized wind (P Cygni profile) or from collisionally ionized gas associated with outflow-driven shocks in the interstellar medium. We estimate the wind launch radius to be approximately 1016 cm (∼104Rg), consistent with the location of the X-ray broadline region. We also resolve a broadened Fe Kα line by σ ∼ 1300 km s−1, placing it at similar scales to the wind, consistent with radii inferred from disk-broadening models and the variability of the Fe Kα broad line. The similarity of the Fe Kα profile to the Hβ wing and broad Paα width indicates that the X-ray-emitting region is likely cospatial with the optical/infrared broadline region and originates from the same gas.

\n
", "doi": "10.3847/2041-8213/ae307d", "issn": "2041-8205", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal Letters", "publication_date": "2026-01-20", "series_number": "1", "volume": "997", "issue": "1", "pages": "L26" }, { "id": "authors:ysqnz-nqk06", "collection": "authors", "collection_id": "ysqnz-nqk06", "cite_using_url": "https://authors.library.caltech.edu/records/ysqnz-nqk06", "type": "article", "title": "The 2025 Failed Outburst of IGR J17091\u22123624: Spectral Evolution and the Role of Ionized Absorbers", "author": [ { "family_name": "Adegoke", "given_name": "Oluwashina K.", "orcid": "0000-0002-5966-4210", "clpid": "Adegoke-Oluwashina-K" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Mastroserio", "given_name": "Guglielmo", "orcid": "0000-0003-4216-7936" }, { "family_name": "Kammoun", "given_name": "Elias", "orcid": "0000-0002-0273-218X", "clpid": "Kammoun-Elias" }, { "family_name": "Connors", "given_name": "Riley M. T.", "orcid": "0000-0002-8908-759X" }, { "family_name": "Steiner", "given_name": "James F.", "orcid": "0000-0002-5872-6061" }, { "family_name": "Harrison", "given_name": "Fiona A.", "orcid": "0000-0003-2992-8024", "clpid": "Harrison-F-A" }, { "family_name": "Buisson", "given_name": "Douglas J. K.", "orcid": "0000-0002-5341-6929" }, { "family_name": "Coley", "given_name": "Joel B.", "orcid": "0000-0001-7532-8359" }, { "family_name": "Coughenour", "given_name": "Benjamin M.", "orcid": "0000-0003-0870-6465" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048" }, { "family_name": "Ewing", "given_name": "Melissa", "orcid": "0000-0001-9349-8271" }, { "family_name": "Ingram", "given_name": "Adam", "orcid": "0000-0002-5311-9078" }, { "family_name": "Kara", "given_name": "Erin", "orcid": "0000-0003-0172-0854" }, { "family_name": "Nathan", "given_name": "Edward", "orcid": "0000-0002-9633-9193" }, { "family_name": "Parra", "given_name": "Maxime", "orcid": "0009-0003-8610-853X" }, { "family_name": "Stern", "given_name": "Daniel", "orcid": "0000-0003-2686-9241", "clpid": "Stern-D" }, { "family_name": "Tomsick", "given_name": "John A.", "orcid": "0000-0001-5506-9855" } ], "abstract": "
\n

IGR J17091−3624 is the only black hole X-ray binary candidate—aside from the well-studied black hole system GRS 1915+105—observed to exhibit a wide range of structured variability patterns in its light curves. In 2025, the source underwent a “failed” outburst: it brightened in the hard state but did not transition to the soft state before returning to quiescence within a few weeks. During this period, IGR J17091−3624 was observed by multiple ground- and space-based facilities. Here, we present results from six pointed NuSTAR observations obtained during the outburst. None of the NuSTAR light curves showed the exotic variability classes typical of the soft state in this source; however, we detected, for the first time, strong dips in the count rate during one epoch, with a total duration of ∼4 ks as seen by NuSTAR. Through spectral and timing analysis of all six epochs, we investigate the hard-state spectral evolution and the nature of the dips. A clear evolution of the coronal properties with luminosity is observed over all six epochs, with clear signatures of relativistic disk reflection that remain largely unchanged across the first five epochs. The first five epochs also show a strong and stable quasiperiodic oscillation feature in the power spectra. The dips observed in Epoch 5 are consistent with partial obscuration by ionized material with a column density NH ≈ 2.0 × 1023 cm−2. We discuss possible origins for this material and place constraints on the orbital parameters and distance of the system.

\n
", "doi": "10.3847/1538-4357/ae1471", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2025-12-20", "series_number": "2", "volume": "995", "issue": "2", "pages": "143" }, { "id": "authors:9n6n4-7da46", "collection": "authors", "collection_id": "9n6n4-7da46", "cite_using_url": "https://authors.library.caltech.edu/records/9n6n4-7da46", "type": "article", "title": "A Sharper View of the X-Ray Spectrum of MCG\u20136-30-15 with XRISM, XMM-Newton, and NuSTAR", "author": [ { "family_name": "Brenneman", "given_name": "Laura W.", "orcid": "0000-0003-2663-1954" }, { "family_name": "Wilkins", "given_name": "Daniel R.", "orcid": "0000-0002-4794-5998" }, { "family_name": "Ogorza\u0142ek", "given_name": "Anna", "orcid": "0000-0003-4504-2557" }, { "family_name": "Rogantini", "given_name": "Daniele", "orcid": "0000-0002-0786-7307" }, { "family_name": "Fabian", "given_name": "Andrew C.", "orcid": "0000-0002-9378-4072" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Jur\u00e1\u0148ov\u00e1", "given_name": "Anna", "orcid": "0000-0002-7292-6852" }, { "family_name": "Mizumoto", "given_name": "Misaki", "orcid": "0000-0003-2161-0361" }, { "family_name": "Noda", "given_name": "Hirofumi", "orcid": "0000-0001-6020-517X" }, { "family_name": "Behar", "given_name": "Ehud", "orcid": "0000-0001-9735-4873" }, { "family_name": "Boissay-Malaquin", "given_name": "Rozenn", "orcid": "0000-0003-2704-599X" }, { "family_name": "Guainazzi", "given_name": "Matteo", "orcid": "0000-0002-1094-3147" }, { "family_name": "Okajima", "given_name": "Takashi", "orcid": "0000-0002-6054-3432" }, { "family_name": "Hoffman", "given_name": "Erika", "orcid": "0000-0003-3496-8928" }, { "family_name": "Keshet", "given_name": "Noa", "orcid": "0000-0003-2535-6436" }, { "family_name": "Kaastra", "given_name": "Jelle", "orcid": "0000-0001-5540-2822" }, { "family_name": "Kara", "given_name": "Erin", "orcid": "0000-0003-0172-0854" }, { "family_name": "Yamauchi", "given_name": "Makoto", "orcid": "0000-0003-1100-1423" } ], "abstract": "
\n

We present a time-averaged spectral analysis of the 2024 XRISM observation of the narrow-line Seyfert-1 galaxy MCG–6-30-15, taken contemporaneously with XMM-Newton and NuSTAR. Our analysis leverages a unique combination of broadband and high-resolution X-ray spectroscopy to definitively isolate and characterize both broad and narrow emission and absorption features in this source. The best-fitting model for the joint spectral analysis is very well described by reflection from the inner accretion disk illuminated by a compact corona, modified by multizone ionized absorption from an outflowing wind along the line of sight. The XRISM/Resolve data confirm that a strong, relativistically broadened Fe Kα emission line is required in order to obtain an adequate model fit. The Resolve data additionally verify the presence of a vout ∼ 2300 km s−1 component of this outflowing wind, find tentative evidence for a vout ∼ 20,000 km s−1 wind component, and indicate that the reflection from distant, neutral material may originate in a nonuniform structure rather than the traditional torus of AGN unification schemes. Though a rapid prograde black hole spin is statistically preferred by the best-fitting model, consistent with previous results, the AGN flux variability over the course of the observation complicates the interpretation of the time-averaged spectra. This insight, clarified by the combination of high signal-to-noise and high spectral resolution in the joint data set, emphasizes the importance of time-resolved, high-resolution spectral analysis in unambiguously measuring the physical properties of variable AGN.

\n
", "doi": "10.3847/1538-4357/ae1225", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2025-12-20", "series_number": "2", "volume": "995", "issue": "2", "pages": "200" }, { "id": "authors:1pbm3-8pn73", "collection": "authors", "collection_id": "1pbm3-8pn73", "cite_using_url": "https://authors.library.caltech.edu/records/1pbm3-8pn73", "type": "article", "title": "A XRISM View of Relativistic Reflection in Cygnus X-1", "author": [ { "family_name": "Draghis", "given_name": "Paul A.", "orcid": "0000-0002-2218-2306" }, { "family_name": "Miller", "given_name": "Jon M.", "orcid": "0000-0003-2869-7682" }, { "family_name": "Kara", "given_name": "Erin", "orcid": "0000-0003-0172-0854" }, { "family_name": "Costantini", "given_name": "Elisa", "orcid": "0000-0001-8470-749X" }, { "family_name": "Adegoke", "given_name": "Oluwashina", "orcid": "0000-0002-5966-4210", "clpid": "Adegoke-Oluwashina" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" } ], "abstract": "

We present the first high-resolution XRISM/Resolve view of the relativistically broadened Fe K line in Cygnus X-1. The data clearly separate the relativistic broad line from the underlying continuum and from narrow emission and absorption features in the Fe band. The unprecedented spectral resolution in the Fe K band clearly demonstrates that the flux excess can be attributed to a single, broad feature, as opposed to a superposition of previously unresolved narrow features. This broad feature can be best interpreted as emission consistent with an origin near the innermost stable circular orbit around a rapidly rotating black hole. By modeling the shape of the broad line, we find a black hole spin of a  \u2243 0.98 and an inclination of the inner accretion disk of θ  \u2243 63 \u2218 . The spin is consistent with prior reflection studies, reaffirming the robustness of past spin measurements using the relativistic reflection method. The measured inclination provides reinforcing evidence of a disk-orbit misalignment in Cygnus X-1. These results highlight the unique abilities of XRISM in separating overlapping spectral features and providing constraints on the geometry of accretion in X-ray binaries.

", "doi": "10.3847/2041-8213/ae2276", "issn": "2041-8205", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal Letters", "publication_date": "2025-12-10", "series_number": "1", "volume": "995", "issue": "1", "pages": "L12" }, { "id": "authors:65ery-v7c65", "collection": "authors", "collection_id": "65ery-v7c65", "cite_using_url": "https://authors.library.caltech.edu/records/65ery-v7c65", "type": "article", "title": "Relativistic reflection within an extended hot plasma geometry", "author": [ { "family_name": "Nekrasov", "given_name": "A. D.", "orcid": "0000-0001-8563-1407" }, { "family_name": "Dauser", "given_name": "T.", "orcid": "0000-0003-4583-9048" }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Walton", "given_name": "D. J.", "orcid": "0000-0001-5819-3552" }, { "family_name": "Fromm", "given_name": "C. M.", "orcid": "0000-0002-1827-1656" }, { "family_name": "Young", "given_name": "A. J.", "orcid": "0000-0003-3626-9151" }, { "family_name": "Baker", "given_name": "F. J. E." }, { "family_name": "Joyce", "given_name": "A. M.", "orcid": "0000-0001-5437-8541" }, { "family_name": "K\u00f6nig", "given_name": "O.", "orcid": "0000-0001-8670-4575" }, { "family_name": "Licklederer", "given_name": "S.", "orcid": "0000-0002-3720-4408" }, { "family_name": "H\u00e4fner", "given_name": "J." }, { "family_name": "Wilms", "given_name": "J.", "orcid": "0000-0003-2065-5410" } ], "abstract": "

Context. The reflection of X-rays at the inner accretion disk around black holes imprints relativistically broadened features in the observed spectrum. Aside from the black hole properties and the ionization and density of the accretion disk, these features also depend on the location and geometry of the primary source of X-rays, often referred to as the corona.

\n

Aims. We present a fast general relativistic model for spectral fitting of a radially extended, ring-like corona above the accretion disk.

\n

Methods. A common approach used to explain observed X-ray reflection spectra is the lamp post geometry, which assumes a point-like source on the rotational axis of the black hole. While it is typically able to explain the observations, this geometric model does not allow for any constraint to be placed on the radial size of the corona. We therefore extended the publicly available relativistic reflection model RELXILL by implementing a radially extended, ring-like primary source.

\n

Results. With the new RELXILL model allowing us to vary the position of the primary source in two dimensions, we present simulated line profiles and spectra and discuss the implications of carrying out a data fitting, in comparison to the lamp post model. We applied this extended RELXILL model to XMM-Newton and NuSTAR data of the radio-quiet Seyfert-2 active galactic nucleus (AGN) ESO 033-G002. The new model describes the data well and we are able to constrain the distance of the source to the black hole to be less than three gravitational radii, while the angular position of the source is poorly constrained.

\n

Conclusions. We show that a compact, radially extended corona close to the innermost stable circular orbit is able to explain the observed relativistic reflection as well as the lamp post corona does. This model has been made freely available to the community.

", "doi": "10.1051/0004-6361/202556012", "issn": "0004-6361", "publisher": "EDP Sciences", "publication": "Astronomy & Astrophysics", "publication_date": "2025-12", "volume": "704", "pages": "A129" }, { "id": "authors:h8g40-s0x22", "collection": "authors", "collection_id": "h8g40-s0x22", "cite_using_url": "https://authors.library.caltech.edu/records/h8g40-s0x22", "type": "article", "title": "Comparing XRISM Cluster Velocity Dispersions with Predictions from Cosmological Simulations: Are Feedback Models Too Ejective?", "author": [ { "family_name": "Audard", "given_name": "Marc", "orcid": "0000-0003-4721-034X" }, { "family_name": "Awaki", "given_name": "Hisamitsu" }, { "family_name": "Ballhausen", "given_name": "Ralf", "orcid": "0000-0002-1118-8470" }, { "family_name": "Bamba", "given_name": "Aya", "orcid": "0000-0003-0890-4920" }, { "family_name": "Behar", "given_name": "Ehud", "orcid": "0000-0001-9735-4873" }, { "family_name": "Boissay-Malaquin", "given_name": "Rozenn", "orcid": "0000-0003-2704-599X" }, { "family_name": "Brenneman", "given_name": "Laura", "orcid": "0000-0003-2663-1954" }, { "family_name": "Brown", "given_name": "Gregory V.", "orcid": "0000-0001-6338-9445" }, { "family_name": "Corrales", "given_name": "Lia", "orcid": "0000-0002-5466-3817" }, { "family_name": "Costantini", "given_name": "Elisa", "orcid": "0000-0001-8470-749X" }, { "family_name": "Cumbee", "given_name": "Renata", "orcid": "0000-0001-9894-295X" }, { "family_name": "Diaz Trigo", "given_name": "Maria", "orcid": "0000-0001-7796-4279" }, { "family_name": "Done", "given_name": "Chris", "orcid": "0000-0002-1065-7239" }, { "family_name": "Dotani", "given_name": "Tadayasu" }, { "family_name": "Ebisawa", "given_name": "Ken", "orcid": "0000-0002-5352-7178" }, { "family_name": "Eckart", "given_name": "Megan E.", "orcid": "0000-0003-3894-5889" }, { "family_name": "Eckert", "given_name": "Dominique", "orcid": "0000-0001-7917-3892" }, { "family_name": "Eguchi", "given_name": "Satoshi", "orcid": "0000-0003-2814-9336" }, { "family_name": "Enoto", "given_name": "Teruaki", "orcid": "0000-0003-1244-3100" }, { "family_name": "Ezoe", "given_name": "Yuichiro" }, { "family_name": "Foster", "given_name": "Adam", "orcid": "0000-0003-3462-8886" }, { "family_name": "Fujimoto", "given_name": "Ryuichi", "orcid": "0000-0002-2374-7073" }, { "family_name": "Fujita", "given_name": "Yutaka", "orcid": "0000-0003-0058-9719" }, { "family_name": "Fukazawa", "given_name": "Yasushi", "orcid": "0000-0002-0921-8837" }, { "family_name": "Fukushima", "given_name": "Kotaro", "orcid": "0000-0001-8055-7113" }, { "family_name": "Furuzawa", "given_name": "Akihiro" }, { "family_name": "Gallo", "given_name": "Luigi", "orcid": "0009-0006-4968-7108" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Gu", "given_name": "Liyi", "orcid": "0000-0001-9911-7038" }, { "family_name": "Guainazzi", "given_name": "Matteo", 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"0000-0001-5880-0703" }, { "family_name": "Tanaka", "given_name": "Keita" }, { "family_name": "Truong", "given_name": "Nhut", "orcid": "0000-0003-4983-0462" }, { "family_name": "Wik", "given_name": "Daniel R.", "orcid": "0000-0001-9110-2245" }, { "family_name": "Zhang", "given_name": "Congyao", "orcid": "0000-0001-5888-7052" }, { "family_name": "ZuHone", "given_name": "John", "orcid": "0000-0003-3175-2347" }, { "literal": "XRISM Collaboration" } ], "abstract": "

The dynamics of the intracluster medium (ICM), the hot plasma that fills galaxy clusters, are shaped by gravity-driven cluster mergers and feedback from supermassive black holes (SMBHs) in the cluster cores. XRISM measurements of ICM velocities in several clusters offer insights into these processes. We compare XRISM measurements for nine galaxy clusters (Virgo, Perseus, Centaurus, Hydra-A, PKS 0745–19, A2029, Coma, A2319, and Ophiuchus) with predictions from three state-of-the-art cosmological simulation suites, TNG-Cluster, the Three Hundred Project GADGET-X, and GIZMO-SIMBA, that employ different models of feedback. In cool cores, XRISM reveals systematically lower velocity dispersions than the simulations predict, with all 10 measurements below the median simulated values by a factor of 1.5–1.7 on average and all falling within the bottom 10% of the predicted distributions. The observed kinetic-to-total pressure ratio is also lower, with a median value of 2.2%, compared to the predicted 5.0%–6.5% for the three simulations. Outside the cool cores and in non-cool-core (NCC) clusters, simulations show better agreement with XRISM measurements, except for the outskirts of the relaxed, cool-core cluster A2029, which exhibits an exceptionally low kinetic pressure support (<1%), with none of the simulated systems in either of the three suites reaching such low levels. The NCC Coma and A2319 exhibit dispersions at the lower end but within the simulated spread. Our comparison suggests that the three numerical models may overestimate the kinetic effects of SMBH feedback in cluster cores. Additional XRISM observations of NCC clusters will clarify if there is a systematic tension in the gravity-dominated regime as well.

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{ "family_name": "Simionescu", "given_name": "Aurora", "orcid": "0000-0002-9714-3862" }, { "family_name": "Smith", "given_name": "Randall", "orcid": "0000-0003-4284-4167" }, { "family_name": "Suzuki", "given_name": "Hiromasa" }, { "family_name": "Szymkowiak", "given_name": "Andrew", "orcid": "0000-0002-4974-687X" }, { "family_name": "Takahashi", "given_name": "Hiromitsu", "orcid": "0000-0001-6314-5897" }, { "family_name": "Takeo", "given_name": "Mai" }, { "family_name": "Tamagawa", "given_name": "Toru", "orcid": "0000-0002-8801-6263" }, { "family_name": "Tamura", "given_name": "Keisuke", "orcid": "0000-0002-6677-3917" }, { "family_name": "Tanaka", "given_name": "Takaaki", "orcid": "0000-0002-4383-0368" }, { "family_name": "Tanimoto", "given_name": "Atsushi" }, { "family_name": "Tashiro", "given_name": "Makoto", "orcid": "0000-0002-5097-1257" }, { "family_name": "Terada", "given_name": "Yukikatsu", "orcid": "0000-0002-2359-1857" }, { "family_name": "Terashima", "given_name": "Yuichi" }, { "family_name": "Tsuboi", "given_name": "Yohko" }, { "family_name": "Tsujimoto", "given_name": "Masahiro" }, { "family_name": "Tsunemi", "given_name": "Hiroshi" }, { "family_name": "Tsuru", "given_name": "Takeshi G.", "orcid": "0000-0002-5504-4903" }, { "family_name": "T\u00fcmer", "given_name": "Ayseg\u00fcl" }, { "family_name": "Uchida", "given_name": "Hiroyuki" }, { "family_name": "Uchida", "given_name": "Nagomi" }, { "family_name": "Uchida", "given_name": "Yuusuke", "orcid": "0000-0002-7962-4136" }, { "family_name": "Uchiyama", "given_name": "Hideki", "orcid": "0000-0003-4580-4021" }, { "family_name": "Ueda", "given_name": "Yoshihiro", "orcid": "0000-0001-7821-6715" }, { "family_name": "Uno", "given_name": "Shinichiro" }, { "family_name": "Vink", "given_name": "Jacco", "orcid": "0000-0002-4708-4219" }, { "family_name": "Watanabe", "given_name": "Shin", "orcid": "0000-0003-0441-7404" }, { "family_name": "Williams", "given_name": "Brian J.", "orcid": "0000-0003-2063-381X" }, { "family_name": "Yamada", "given_name": "Satoshi" }, { "family_name": "Yamada", "given_name": "Shinya", "orcid": "0000-0003-4808-893X" }, { "family_name": "Yamaguchi", "given_name": "Hiroya" }, { "family_name": "Yamaoka", "given_name": "Kazutaka", "orcid": "0000-0003-3841-0980" }, { "family_name": "Yamasaki", "given_name": "Noriko", "orcid": "0000-0003-4885-5537" }, { "family_name": "Yamauchi", "given_name": "Makoto", "orcid": "0000-0003-1100-1423" }, { "family_name": "Yamauchi", "given_name": "Shigeo" }, { "family_name": "Yaqoob", "given_name": "Tahir" }, { "family_name": "Yoneyama", "given_name": "Tomokage" }, { "family_name": "Yoshida", "given_name": "Tessei" }, { "family_name": "Yukita", "given_name": "Mihoko" }, { "family_name": "Zhuravleva", "given_name": "Irina", "orcid": "0000-0001-7630-8085" }, { "family_name": "Neilsen", "given_name": "Joey", "orcid": "0000-0002-8247-786X" }, { "family_name": "Tomaru", "given_name": "Ryota", "orcid": "0000-0002-6797-2539" }, { "family_name": "Mehdipour", "given_name": "Missagh", "orcid": "0000-0002-4992-4664" }, { "literal": "XRISM collaboration" } ], "abstract": "

Accretion disks in strong gravity ubiquitously produce winds, seen as blueshifted absorption lines in the X-ray band of both stellar mass X-ray binaries (black holes and neutron stars) and supermassive black holes. Some of the most powerful winds (termed Eddington winds) are expected to arise from systems in which radiation pressure is sufficient to unbind material from the inner disk (L \u2273 LEdd). These winds should be extremely fast and carry a large amount of kinetic power, which, when associated with supermassive black holes, would make them a prime contender for the feedback mechanism linking the growth of those black holes with their host galaxies. Here we show the XRISM Resolve spectrum of the galactic neutron star X-ray binary, GX 13+1, which reveals one of the densest winds ever seen in absorption lines. This Compton-thick wind significantly attenuates the flux, making it appear faint, although it is intrinsically more luminous than usual (L \u2273 LEdd). However, the wind is extremely slow, more consistent with the predictions of thermal-radiative winds launched by X-ray irradiation of the outer disk than with the expected Eddington wind driven by radiation pressure from the inner disk. This puts new constraints on the origin of winds from bright accretion flows in binaries, but also highlights the very different origin required for the ultrafast (v ~ 0.3c) winds seen in recent Resolve observations of a supermassive black hole at a similarly high Eddington ratio.

", "doi": "10.1038/s41586-025-09495-w", "pmcid": "PMC12488489", "issn": "0028-0836", "publisher": "Nature Publishing Group", "publication": "Nature", "publication_date": "2025-10-02", "series_number": "8083", "volume": "646", "issue": "8083", "pages": "57-61" }, { "id": "authors:jztf3-q8b31", "collection": "authors", "collection_id": "jztf3-q8b31", "cite_using_url": "https://authors.library.caltech.edu/records/jztf3-q8b31", "type": "article", "title": "Delving into the depths of NGC 3783 with XRISM. II. 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"family_name": "Ogawa", "given_name": "Shoji", "orcid": "0000-0002-5701-0811" }, { "family_name": "Ogorzalek", "given_name": "Anna", "orcid": "0000-0003-4504-2557" }, { "family_name": "Okajima", "given_name": "Takashi", "orcid": "0000-0002-6054-3432" }, { "family_name": "Ota", "given_name": "Naomi", "orcid": "0000-0002-2784-3652" }, { "family_name": "Paltani", "given_name": "Stephane", "orcid": "0000-0002-8108-9179" }, { "family_name": "Petre", "given_name": "Robert", "orcid": "0000-0003-3850-2041" }, { "family_name": "Plucinsky", "given_name": "Paul", "orcid": "0000-0003-1415-5823" }, { "family_name": "Porter", "given_name": "Frederick S.", "orcid": "0000-0002-6374-1119" }, { "family_name": "Pottschmidt", "given_name": "Katja" }, { "family_name": "Sato", "given_name": "Kosuke", "orcid": "0000-0001-5774-1633" }, { "family_name": "Sato", "given_name": "Toshiki" }, { "family_name": "Sawada", "given_name": "Makoto", "orcid": "0000-0003-2008-6887" }, { "family_name": "Seta", "given_name": "Hiromi" }, { "family_name": "Shidatsu", "given_name": "Megumi", "orcid": "0000-0001-8195-6546" }, { "family_name": "Simionescu", "given_name": "Aurora" }, { "family_name": "Smith", "given_name": "Randall", "orcid": "0000-0003-4284-4167" }, { "family_name": "Suzuki", "given_name": "Hiromasa" }, { "family_name": "Szymkowiak", "given_name": "Andrew", "orcid": "0000-0002-4974-687X" }, { "family_name": "Takahashi", "given_name": "Hiromitsu", "orcid": "0000-0001-6314-5897" }, { "family_name": "Takeo", "given_name": "Mai" }, { "family_name": "Tamagawa", "given_name": "Toru", "orcid": "0000-0002-8801-6263" }, { "family_name": "Tamura", "given_name": "Keisuke", "orcid": "0009-0004-7101-4503" }, { "family_name": "Tanaka", "given_name": "Takaaki", "orcid": "0000-0002-4383-0368" }, { "family_name": "Tanimoto", "given_name": "Atsushi", "orcid": "0000-0002-0114-5581" }, { "family_name": "Tashiro", "given_name": "Makoto", "orcid": "0000-0002-5097-1257" }, { "family_name": "Terada", "given_name": "Yukikatsu" }, { "family_name": "Terashima", "given_name": "Yuichi", "orcid": "0000-0003-1780-5481" }, { "family_name": "Tsuboi", "given_name": "Yohko", "orcid": "0000-0001-9943-0024" }, { "family_name": "Tsujimoto", "given_name": "Masahiro", "orcid": "0000-0002-9184-5556" }, { "family_name": "Tsunemi", "given_name": "Hiroshi", "orcid": "0000-0003-4379-5643" }, { "family_name": "Tsuru", "given_name": "Takeshi", "orcid": "0000-0002-5504-4903" }, { "family_name": "T\u00fcmer", "given_name": "Ay\u015feg\u00fcl", "orcid": "0000-0002-3132-8776" }, { "family_name": "Uchida", "given_name": "Hiroyuki" }, { "family_name": "Uchida", "given_name": "Nagomi" }, { "family_name": "Uchida", "given_name": "Yuusuke" }, { "family_name": "Uchiyama", "given_name": "Hideki", "orcid": "0000-0003-4580-4021" }, { "family_name": "Ueda", "given_name": "Yoshihiro", "orcid": "0000-0001-7821-6715" }, { "family_name": "Uno", "given_name": "Shinichiro" }, { "family_name": "Vink", "given_name": "Jacco" }, { "family_name": "Watanabe", "given_name": "Shin" }, { "family_name": "Williams", "given_name": "Brian J.", "orcid": "0000-0003-2063-381X" }, { "family_name": "Yamada", "given_name": "Satoshi", "orcid": "0000-0002-9754-3081" }, { "family_name": "Yamada", "given_name": "Shinya", "orcid": "0000-0003-4808-893X" }, { "family_name": "Yamaguchi", "given_name": "Hiroya" }, { "family_name": "Yamaoka", "given_name": "Kazutaka" }, { "family_name": "Yamasaki", "given_name": "Noriko", "orcid": "0000-0003-4885-5537" }, { "family_name": "Yamauchi", "given_name": "Makoto", "orcid": "0000-0003-1100-1423" }, { "family_name": "Yamauchi", "given_name": "Shigeo" }, { "family_name": "Yaqoob", "given_name": "Tahir" }, { "family_name": "Yoneyama", "given_name": "Tomokage", "orcid": "0000-0002-2683-6856" }, { "family_name": "Yoshida", "given_name": "Tessei" }, { "family_name": "Yukita", "given_name": "Mihoko", "orcid": "0000-0001-6366-3459" }, { "family_name": "Zhuravleva", "given_name": "Irina", "orcid": "0000-0001-7630-8085" }, { "family_name": "Diez", "given_name": "Camille", "orcid": "0000-0001-6520-4600" }, { "family_name": "Fukumura", "given_name": "Keigo", "orcid": "0000-0001-5709-7606" }, { "family_name": "Li", "given_name": "Chen", "orcid": "0000-0001-5493-7585" }, { "family_name": "Mehdipour", "given_name": "Missagh", "orcid": "0000-0002-4992-4664" }, { "family_name": "Panagiotou", "given_name": "Christos", "orcid": "0009-0001-9034-6261" }, { "family_name": "Signorini", "given_name": "Matilde", "orcid": "0000-0002-8177-6905" }, { "family_name": "Zhao", "given_name": "Keqin", "orcid": "0000-0003-1252-8227" }, { "literal": "XRISM Collaboration" } ], "abstract": "

Context. Accurate X-ray spectroscopic measurements are fundamental for deriving basic physical parameters of the most abundant baryon components in the Universe. The plethora of X-ray observatories currently operational enables a panchromatic view of the high-energy emission of celestial sources. However, uncertainties in the energy-dependent calibration of the instrument transfer functions (e.g. the effective area, energy redistribution, or gain) can limit - and historically, did limit - the accuracy of X-ray spectroscopic measurements. Aims. We revised the status of the cross-calibration among the scientific payload on board four operation missions: Chandra, NuSTAR, XMM-Newton, and the recently launched XRISM. XRISM carries the micro-calorimeter Resolve, which yields the best energy resolution at energies ≥2 keV. For this purpose, we used the data from a 10-day-long observational campaign targeting the nearby active galactic nucleus NGC 3783, carried out in July 2024. Methods. We present a novel model-independent method for assessing the cross-calibration status that is based on a multi-node spline of the spectra with the highest-resolving power (XRISM/Resolve in our campaign). We also estimated the impact of the intrinsic variability of NGC 3783 on the cross-calibration status due to the different time coverages of participating observatories and performed an empirical reassessment of the Resolve throughput at low energies. Results. Based on this analysis, we derived a set of energy-dependent correction factors of the observed responses, enabling a statistically robust analysis of the whole spectral dataset. They will be employed in subsequent papers describing the astrophysical results of the campaign.

", "doi": "10.1051/0004-6361/202556000", "issn": "0004-6361", "publisher": "EDP Sciences", "publication": "Astronomy & Astrophysics", "publication_date": "2025-10", "volume": "702", "pages": "A147" }, { "id": "authors:k3g06-mav59", "collection": "authors", "collection_id": "k3g06-mav59", "cite_using_url": "https://authors.library.caltech.edu/records/k3g06-mav59", "type": "article", "title": "The structure of the relativistic Fe line in GX\u00a0340+0 as viewed with XRISM/Resolve, NICER, and NuSTAR", "author": [ { "family_name": "Ludlam", "given_name": "Renee M", "orcid": "0000-0002-8961-939X" }, { "family_name": "Ballhausen", "given_name": "Ralf", "orcid": "0000-0002-1118-8470" }, { "family_name": "Chakraborty", "given_name": "Priyanka", "orcid": "0000-0002-4469-2518" }, { "family_name": "Costantini", "given_name": "Elisa", "orcid": "0000-0001-8470-749X" }, { "family_name": "Corrales", "given_name": "Lia", "orcid": "0000-0002-5466-3817" }, { "family_name": "Hall", "given_name": "Hayden", "orcid": "0009-0000-4409-7914" }, { "family_name": "Kilbourne", "given_name": "Caroline A", "orcid": "0000-0001-9464-4103" }, { "family_name": "Moutard", "given_name": "David L", "orcid": "0000-0003-1463-8702" }, { "family_name": "Nakagawa", "given_name": "Takao", "orcid": "0000-0002-6660-9375" }, { "family_name": "Porter", "given_name": "Frederick S", "orcid": "0000-0002-6374-1119" }, { "family_name": "Psaradaki", "given_name": "Ioanna", "orcid": "0000-0002-1049-3182" }, { "family_name": "Sudha", "given_name": "Malu", "orcid": "0000-0003-0440-7978" }, { "family_name": "Smith", "given_name": "Randall K", "orcid": "0000-0003-4284-4167" }, { "family_name": "Takahashi", "given_name": "Hiromitsu", "orcid": "0000-0001-6314-5897" }, { "family_name": "Done", "given_name": "Chris", "orcid": "0000-0002-1065-7239" }, { "family_name": "Garc\u00eda", "given_name": "Javier A", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" } ], "abstract": "

We present a 152 ks XRISM/Resolve observation of the persistently accreting Z source GX 3400. Simultaneous observations also occurred with NuSTAR and NICER for 22.47 ks and 2.7 ks, respectively. The source covered the normal branch to the flaring branching during the observations. The data from all three missions were modeled concurrently for each spectral branch. The superior energy resolution of XRISM/Resolve reveals structure within the iron emission line complex regardless of spectral state. We model the reprocessed Fe K line with a reflection model tailored for thermal illumination of the accretion disk by a neutron star. The currently available model encompasses the broad components, but narrow emission features remain at the ~5% level. These remaining features may be described by the presence of an ionized plasma in the system as has been observed in the Z source Cygnus X-2, but subsequent updates to the reflection model code may be able to explain these features.

", "doi": "10.1093/pasj/psaf085", "issn": "0004-6264", "publisher": "Oxford University Press (OUP)", "publication": "Publications of the Astronomical Society of Japan", "publication_date": "2025-09", "series_number": "S1", "volume": "77", "issue": "S1", "pages": "S117-S130" }, { "id": "authors:30wzr-nng02", "collection": "authors", "collection_id": "30wzr-nng02", "cite_using_url": "https://authors.library.caltech.edu/records/30wzr-nng02", "type": "article", "title": "Constraining gas motion and non-thermal pressure beyond the core of the Abell\u00a02029 galaxy cluster with XRISM", "author": [ { "family_name": "Audard", "given_name": "Marc" }, { "family_name": "Awaki", "given_name": "Hisamitsu" }, { "family_name": "Ballhausen", "given_name": "Ralf", "orcid": "0000-0002-1118-8470" }, { "family_name": "Bamba", "given_name": "Aya", "orcid": "0000-0003-0890-4920" }, { "family_name": "Behar", "given_name": "Ehud", "orcid": "0000-0001-9735-4873" }, { "family_name": "Boissay-Malaquin", "given_name": "Rozenn", "orcid": "0000-0003-2704-599X" }, { "family_name": "Brenneman", "given_name": "Laura", "orcid": "0000-0003-2663-1954" }, { "family_name": "Brown", "given_name": "Gregory", "orcid": "0000-0001-6338-9445" }, { "family_name": "Corrales", "given_name": "Lia", "orcid": "0000-0002-5466-3817" }, { "family_name": "Costantini", "given_name": "Elisa", "orcid": "0000-0001-8470-749X" }, { "family_name": "Cumbee", "given_name": "Renata", "orcid": "0000-0001-9894-295X" }, { "family_name": "Diaz\u00a0Trigo", "given_name": "Maria", "orcid": "0000-0001-7796-4279" }, { "family_name": "Done", "given_name": "Chris", "orcid": "0000-0002-1065-7239" }, { "family_name": "Dotani", "given_name": "Tadayasu" }, { "family_name": "Ebisawa", "given_name": "Ken", "orcid": "0000-0002-5352-7178" }, { "family_name": "Eckart", "given_name": "Megan", "orcid": "0000-0003-3894-5889" }, { "family_name": "Eckert", "given_name": "Dominique", "orcid": "0000-0001-7917-3892" }, { "family_name": "Eguchi", "given_name": "Satoshi", "orcid": "0000-0003-2814-9336" }, { "family_name": "Enoto", "given_name": "Teruaki", "orcid": "0000-0003-1244-3100" }, { "family_name": "Ezoe", "given_name": "Yuichiro" }, { "family_name": "Foster", "given_name": "Adam", "orcid": "0000-0003-3462-8886" }, { "family_name": "Fujimoto", "given_name": "Ryuichi", "orcid": "0000-0002-2374-7073" }, { "family_name": "Fujita", "given_name": "Yutaka", "orcid": "0000-0003-0058-9719" }, { "family_name": "Fukazawa", "given_name": "Yasushi", "orcid": "0000-0002-0921-8837" }, { "family_name": "Fukushima", "given_name": "Kotaro", "orcid": "0000-0001-8055-7113" }, { "family_name": "Furuzawa", "given_name": "Akihiro" }, { "family_name": "Gallo", "given_name": "Luigi", "orcid": "0009-0006-4968-7108" }, { "family_name": "Garc\u00eda", "given_name": "Javier", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Gu", "given_name": "Liyi", "orcid": "0000-0001-9911-7038" }, { "family_name": "Guainazzi", "given_name": "Matteo", "orcid": "0000-0002-1094-3147" }, { "family_name": "Hagino", "given_name": "Kouichi", "orcid": "0000-0003-4235-5304" }, { "family_name": "Hamaguchi", "given_name": "Kenji", "orcid": "0000-0001-7515-2779" }, { "family_name": "Hatsukade", "given_name": "Isamu", "orcid": "0000-0003-3518-3049" }, { "family_name": "Hayashi", "given_name": "Katsuhiro", "orcid": "0000-0001-6922-6583" }, { "family_name": "Hayashi", "given_name": "Takayuki", "orcid": "0000-0001-6665-2499" }, { "family_name": "Hell", "given_name": "Natalie", "orcid": "0000-0003-3057-1536" }, { "family_name": "Hodges-Kluck", "given_name": "Edmund", "orcid": "0000-0002-2397-206X" }, { "family_name": "Hornschemeier", "given_name": "Ann", "orcid": "0000-0001-8667-2681" }, { "family_name": "Ichinohe", "given_name": "Yuto", "orcid": "0000-0002-6102-1441" }, { "family_name": "Ishi", "given_name": "Daiki" }, { "family_name": "Ishida", "given_name": "Manabu" }, { "family_name": "Ishikawa", "given_name": "Kumi" }, { "family_name": "Ishisaki", "given_name": "Yoshitaka" }, { "family_name": "Kaastra", "given_name": "Jelle", "orcid": "0000-0001-5540-2822" }, { "family_name": "Kallman", "given_name": "Timothy" }, { "family_name": "Kara", "given_name": "Erin", "orcid": "0000-0003-0172-0854" }, { "family_name": "Katsuda", "given_name": "Satoru", "orcid": "0000-0002-1104-7205" }, { "family_name": "Kanemaru", "given_name": "Yoshiaki", "orcid": "0000-0002-4541-1044" }, { "family_name": "Kelley", "given_name": "Richard", "orcid": "0009-0007-2283-3336" }, { "family_name": "Kilbourne", "given_name": "Caroline", "orcid": "0000-0001-9464-4103" }, { "family_name": "Kitamoto", "given_name": "Shunji", "orcid": "0000-0001-8948-7983" }, { "family_name": "Kobayashi", "given_name": "Shogo", "orcid": "0000-0001-7773-9266" }, { "family_name": "Kohmura", "given_name": "Takayoshi" }, { "family_name": "Kubota", "given_name": "Aya" }, { "family_name": "Leutenegger", "given_name": "Maurice", "orcid": "0000-0002-3331-7595" }, { "family_name": "Loewenstein", "given_name": "Michael", "orcid": "0000-0002-1661-4029" }, { "family_name": "Maeda", "given_name": "Yoshitomo", "orcid": "0000-0002-9099-5755" }, { "family_name": "Markevitch", "given_name": "Maxim" }, { "family_name": "Matsumoto", "given_name": "Hironori" }, { "family_name": "Matsushita", "given_name": "Kyoko", "orcid": "0000-0003-2907-0902" }, { "family_name": "McCammon", "given_name": "Dan", "orcid": "0000-0001-5170-4567" }, { "family_name": "McNamara", "given_name": "Brian" }, { "family_name": "Mernier", "given_name": "Fran\u00e7ois", "orcid": "0000-0002-7031-4772" }, { "family_name": "Miller", "given_name": "Eric", "orcid": "0000-0002-3031-2326" }, { "family_name": "Miller", "given_name": "Jon", "orcid": "0000-0003-2869-7682" }, { "family_name": "Mitsuishi", "given_name": "Ikuyuki", "orcid": "0000-0002-9901-233X" }, { "family_name": "Mizumoto", "given_name": "Misaki", "orcid": "0000-0003-2161-0361" }, { "family_name": "Mizuno", "given_name": "Tsunefumi", "orcid": "0000-0001-7263-0296" }, { "family_name": "Mori", "given_name": "Koji", "orcid": "0000-0002-0018-0369" }, { "family_name": "Mukai", "given_name": "Koji", "orcid": "0000-0002-8286-8094" }, { "family_name": "Murakami", "given_name": "Hiroshi" }, { "family_name": "Mushotzky", "given_name": "Richard", "orcid": "0000-0002-7962-5446" }, { "family_name": "Nakajima", "given_name": "Hiroshi", "orcid": "0000-0001-6988-3938" }, { "family_name": "Nakazawa", "given_name": "Kazuhiro", "orcid": "0000-0003-2930-350X" }, { "family_name": "Ness", "given_name": "Jan-Uwe" }, { "family_name": "Nobukawa", "given_name": "Kumiko", "orcid": "0000-0002-0726-7862" }, { "family_name": "Nobukawa", "given_name": "Masayoshi", "orcid": "0000-0003-1130-5363" }, { "family_name": "Noda", "given_name": "Hirofumi", "orcid": "0000-0001-6020-517X" }, { "family_name": "Odaka", "given_name": "Hirokazu" }, { "family_name": "Ogawa", "given_name": "Shoji", "orcid": "0000-0002-5701-0811" }, { "family_name": "Ogorzalek", "given_name": "Anna", "orcid": "0000-0003-4504-2557" }, { "family_name": "Okajima", "given_name": "Takashi", "orcid": "0000-0002-6054-3432" }, { "family_name": "Ota", "given_name": "Naomi", "orcid": "0000-0002-2784-3652" }, { "family_name": "Paltani", "given_name": "Stephane", "orcid": "0000-0002-8108-9179" }, { "family_name": "Petre", "given_name": "Robert", "orcid": "0000-0003-3850-2041" }, { "family_name": "Plucinsky", "given_name": "Paul", "orcid": "0000-0003-1415-5823" }, { "family_name": "Porter", "given_name": "Frederick", "orcid": "0000-0002-6374-1119" }, { "family_name": "Pottschmidt", "given_name": "Katja", "orcid": "0000-0002-4656-6881" }, { "family_name": "Sato", "given_name": "Kosuke", "orcid": "0000-0001-5774-1633" }, { "family_name": "Sato", "given_name": "Toshiki" }, { "family_name": "Sawada", "given_name": "Makoto", "orcid": "0000-0003-2008-6887" }, { "family_name": "Seta", "given_name": "Hiromi" }, { "family_name": "Shidatsu", "given_name": "Megumi", "orcid": "0000-0001-8195-6546" }, { "family_name": "Simionescu", "given_name": "Aurora", "orcid": "0000-0002-9714-3862" }, { "family_name": "Smith", "given_name": "Randall", "orcid": "0000-0003-4284-4167" }, { "family_name": "Suzuki", "given_name": "Hiromasa", "orcid": "0000-0002-8152-6172" }, { "family_name": "Szymkowiak", "given_name": "Andrew", "orcid": "0000-0002-4974-687X" }, { "family_name": "Takahashi", "given_name": "Hiromitsu", "orcid": "0000-0001-6314-5897" }, { "family_name": "Takeo", "given_name": "Mai" }, { "family_name": "Tamagawa", "given_name": "Toru" }, { "family_name": "Tamura", "given_name": "Keisuke" }, { "family_name": "Tanaka", "given_name": "Takaaki", "orcid": "0000-0002-4383-0368" }, { "family_name": "Tanimoto", "given_name": "Atsushi", "orcid": "0000-0002-0114-5581" }, { "family_name": "Tashiro", "given_name": "Makoto", "orcid": "0000-0002-5097-1257" }, { "family_name": "Terada", "given_name": "Yukikatsu", "orcid": "0000-0002-2359-1857" }, { "family_name": "Terashima", "given_name": "Yuichi", "orcid": "0000-0003-1780-5481" }, { "family_name": "Tsuboi", "given_name": "Yohko" }, { "family_name": "Tsujimoto", "given_name": "Masahiro", "orcid": "0000-0002-9184-5556" }, { "family_name": "Tsunemi", "given_name": "Hiroshi" }, { "family_name": "Tsuru", "given_name": "Takeshi", "orcid": "0000-0002-5504-4903" }, { "family_name": "Uchida", "given_name": "Hiroyuki", "orcid": "0000-0003-1518-2188" }, { "family_name": "Uchida", "given_name": "Nagomi", "orcid": "0000-0002-5641-745X" }, { "family_name": "Uchida", "given_name": "Yuusuke", "orcid": "0000-0002-7962-4136" }, { "family_name": "Uchiyama", "given_name": "Hideki", "orcid": "0000-0003-4580-4021" }, { "family_name": "Ueda", "given_name": "Yoshihiro", "orcid": "0000-0001-7821-6715" }, { "family_name": "Uno", "given_name": "Shinichiro" }, { "family_name": "Vink", "given_name": "Jacco", "orcid": "0000-0002-4708-4219" }, { "family_name": "Watanabe", "given_name": "Shin", "orcid": "0000-0003-0441-7404" }, { "family_name": "Williams", "given_name": "Brian J", "orcid": "0000-0003-2063-381X" }, { "family_name": "Yamada", "given_name": "Satoshi", "orcid": "0000-0002-9754-3081" }, { "family_name": "Yamada", "given_name": "Shinya", "orcid": "0000-0003-4808-893X" }, { "family_name": "Yamaguchi", "given_name": "Hiroya", "orcid": "0000-0002-5092-6085" }, { "family_name": "Yamaoka", "given_name": "Kazutaka", "orcid": "0000-0003-3841-0980" }, { "family_name": "Yamasaki", "given_name": "Noriko", "orcid": "0000-0003-4885-5537" }, { "family_name": "Yamauchi", "given_name": "Makoto", "orcid": "0000-0003-1100-1423" }, { "family_name": "Yamauchi", "given_name": "Shigeo" }, { "family_name": "Yaqoob", "given_name": "Tahir" }, { "family_name": "Yoneyama", "given_name": "Tomokage" }, { "family_name": "Yoshida", "given_name": "Tessei" }, { "family_name": "Yukita", "given_name": "Mihoko", "orcid": "0000-0001-6366-3459" }, { "family_name": "Zhuravleva", "given_name": "Irina", "orcid": "0000-0001-7630-8085" }, { "family_name": "Bartalesi", "given_name": "Tommaso", "orcid": "0009-0004-5838-2213" }, { "family_name": "Ettori", "given_name": "Stefano", "orcid": "0000-0003-4117-8617" }, { "family_name": "Kosarzycki", "given_name": "Roman" }, { "family_name": "Lovisari", "given_name": "Lorenzo", "orcid": "0000-0002-3754-2415" }, { "family_name": "Rose", "given_name": "Tom", "orcid": "0000-0002-8310-2218" }, { "family_name": "Sarkar", "given_name": "Arnab", "orcid": "0000-0002-5222-1337" }, { "family_name": "Sun", "given_name": "Ming", "orcid": "0000-0001-5880-0703" }, { "family_name": "Tamhane", "given_name": "Prathamesh", "orcid": "0000-0001-8176-7665" }, { "literal": "XRISM Collaboration" } ], "abstract": "

We report on a detailed spectroscopic study of the gas dynamics and hydrostatic mass bias of the galaxy cluster Abell 2029, utilizing high-resolution observations from XRISM Resolve. Abell 2029, known for its cool core and relaxed X-ray morphology, provides an excellent opportunity to investigate the influence of gas motions beyond the central region. Expanding upon prior studies that revealed low turbulence and bulk motions within the core, our analysis covers regions out to the scale radius R\u2082\u2085\u2080\u2080 (670 kpc) based on three radial pointings extending from the cluster center toward the northern side. We obtain accurate measurements of bulk and turbulent velocities along the line of sight. The results indicate that non-thermal pressure accounts for no more than 2% of the total pressure at all radii, with a gradual decrease outward. The observed radial trend differs from many numerical simulations, which often predict an increase in non-thermal pressure fraction at larger radii. These findings suggest that deviations from hydrostatic equilibrium are small, leading to a hydrostatic mass bias of around 2% across the observed area.

", "doi": "10.1093/pasj/psaf055", "issn": "0004-6264", "publisher": "Oxford University Press (OUP)", "publication": "Publications of the Astronomical Society of Japan", "publication_date": "2025-09", "series_number": "S1", "volume": "77", "issue": "S1", "pages": "S242-S253" }, { "id": "authors:w222p-9ww86", "collection": "authors", "collection_id": "w222p-9ww86", "cite_using_url": "https://authors.library.caltech.edu/records/w222p-9ww86", "type": "article", "title": "Thermal and kinematic properties of ejecta in SN1987A revealed by XRISM", "author": [ { "family_name": "Audard", "given_name": "Marc", "orcid": "0000-0003-4721-034X" }, { "family_name": "Awaki", "given_name": "Hisamitsu" }, { "family_name": "Ballhausen", "given_name": "Ralf", "orcid": "0000-0002-1118-8470" }, { "family_name": "Bamba", "given_name": "Aya", "orcid": "0000-0003-0890-4920" }, { "family_name": "Behar", "given_name": "Ehud", "orcid": "0000-0001-9735-4873" }, { "family_name": "Boissay-Malaquin", "given_name": "Rozenn", "orcid": "0000-0003-2704-599X" }, { "family_name": "Brenneman", "given_name": "Laura", "orcid": "0000-0003-2663-1954" }, { "family_name": "Brown", "given_name": "Gregory V", "orcid": "0000-0001-6338-9445" }, { "family_name": "Corrales", "given_name": "Lia", "orcid": "0000-0002-5466-3817" }, { "family_name": "Costantini", "given_name": "Elisa", "orcid": "0000-0001-8470-749X" }, { "family_name": "Cumbee", "given_name": "Renata", "orcid": "0000-0001-9894-295X" }, { "family_name": "D\u00edaz\u00a0Trigo", "given_name": "Mar\u00eda", "orcid": "0000-0001-7796-4279" }, { "family_name": "Done", "given_name": "Chris", "orcid": "0000-0002-1065-7239" }, { "family_name": "Dotani", "given_name": "Tadayasu" }, { "family_name": "Ebisawa", "given_name": "Ken", "orcid": "0000-0002-5352-7178" }, { "family_name": "Eckart", "given_name": "Megan E", "orcid": "0000-0003-3894-5889" }, { "family_name": "Eckert", "given_name": "Dominique", "orcid": "0000-0001-7917-3892" }, { "family_name": "Enoto", "given_name": "Teruaki", "orcid": "0000-0003-1244-3100" }, { "family_name": "Eguchi", "given_name": "Satoshi", "orcid": "0000-0003-2814-9336" }, { "family_name": "Ezoe", "given_name": "Yuichiro" }, { "family_name": "Foster", "given_name": "Adam", "orcid": "0000-0003-3462-8886" }, { "family_name": "Fujimoto", "given_name": "Ryuichi", "orcid": "0000-0002-2374-7073" }, { "family_name": "Fujita", "given_name": "Yutaka", "orcid": "0000-0003-0058-9719" }, { "family_name": "Fukazawa", "given_name": "Yasushi", "orcid": "0000-0002-0921-8837" }, { "family_name": "Fukushima", "given_name": "Kotaro", "orcid": "0000-0001-8055-7113" }, { "family_name": "Furuzawa", "given_name": "Akihiro" }, { "family_name": "Gallo", "given_name": "Luigi", "orcid": "0009-0006-4968-7108" }, { "family_name": "Garc\u00eda", "given_name": "Javier A", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Gu", "given_name": "Liyi", "orcid": "0000-0001-9911-7038" }, { "family_name": "Guainazzi", "given_name": "Matteo", "orcid": "0000-0002-1094-3147" }, { "family_name": "Giuffrida", "given_name": "Roberta", "orcid": "0000-0002-2774-3491" }, { "family_name": "Hagino", "given_name": "Kouichi", "orcid": "0000-0003-4235-5304" }, { "family_name": "Hamaguchi", "given_name": "Kenji", "orcid": "0000-0001-7515-2779" }, { "family_name": "Hatsukade", "given_name": "Isamu", "orcid": "0000-0003-3518-3049" }, { "family_name": "Hayashi", "given_name": "Katsuhiro", "orcid": "0000-0001-6922-6583" }, { "family_name": "Hayashi", "given_name": "Takayuki", "orcid": "0000-0001-6665-2499" }, { "family_name": "Hell", "given_name": "Natalie", "orcid": "0000-0003-3057-1536" }, { "family_name": "Hodges-Kluck", "given_name": "Edmund", "orcid": "0000-0002-2397-206X" }, { "family_name": "Hornschemeier", "given_name": "Ann", "orcid": "0000-0001-8667-2681" }, { "family_name": "Ichinohe", "given_name": "Yuto", "orcid": "0000-0002-6102-1441" }, { "family_name": "Ishi", "given_name": "Daiki" }, { "family_name": "Ishida", "given_name": "Manabu" }, { "family_name": "Ishikawa", "given_name": "Kumi" }, { "family_name": "Ishisaki", "given_name": "Yoshitaka" }, { "family_name": "Kaastra", "given_name": "Jelle", "orcid": "0000-0001-5540-2822" }, { "family_name": "Kallman", "given_name": "Timothy", "orcid": "0000-0002-5779-6906" }, { "family_name": "Kara", "given_name": "Erin", "orcid": "0000-0003-0172-0854" }, { "family_name": "Katsuda", "given_name": "Satoru", "orcid": "0000-0002-1104-7205" }, { "family_name": "Kanemaru", "given_name": "Yoshiaki", "orcid": "0000-0002-4541-1044" }, { "family_name": "Kelley", "given_name": "Richard", "orcid": "0009-0007-2283-3336" }, { "family_name": "Kikuchi", "given_name": "Ryunosuke" }, { "family_name": "Kilbourne", "given_name": "Caroline", "orcid": "0000-0001-9464-4103" }, { "family_name": "Kitamoto", "given_name": "Shunji", "orcid": "0000-0001-8948-7983" }, { "family_name": "Kobayashi", "given_name": "Shogo", "orcid": "0000-0001-7773-9266" }, { "family_name": "Kohmura", "given_name": "Takayoshi" }, { "family_name": "Kubota", "given_name": "Aya" }, { "family_name": "Leutenegger", "given_name": "Maurice", "orcid": "0000-0002-3331-7595" }, { "family_name": "Loewenstein", "given_name": "Michael", "orcid": "0000-0002-1661-4029" }, { "family_name": "Maeda", "given_name": "Yoshitomo", "orcid": "0000-0002-9099-5755" }, { "family_name": "Markevitch", "given_name": "Maxim" }, { "family_name": "Matsumoto", "given_name": "Hironori" }, { "family_name": "Matsushima", "given_name": "Tsukasa" }, { "family_name": "Matsushita", "given_name": "Kyoko", "orcid": "0000-0003-2907-0902" }, { "family_name": "McCammon", "given_name": "Dan", "orcid": "0000-0001-5170-4567" }, { "family_name": "McNamara", "given_name": "Brian" }, { "family_name": "Mernier", "given_name": "Fran\u00e7ois", "orcid": "0000-0002-7031-4772" }, { "family_name": "Miller", "given_name": "Eric D", "orcid": "0000-0002-3031-2326" }, { "family_name": "Miller", "given_name": "Jon M", "orcid": "0000-0003-2869-7682" }, { "family_name": "Mitsuishi", "given_name": "Ikuyuki", "orcid": "0000-0002-9901-233X" }, { "family_name": "Mizumoto", "given_name": "Misaki", "orcid": "0000-0003-2161-0361" }, { "family_name": "Mizuno", "given_name": "Tsunefumi", "orcid": "0000-0001-7263-0296" }, { "family_name": "Mori", "given_name": "Koji", "orcid": "0000-0002-0018-0369" }, { "family_name": "Mukai", "given_name": "Koji", "orcid": "0000-0002-8286-8094" }, { "family_name": "Murakami", "given_name": "Hiroshi" }, { "family_name": "Mushotzky", "given_name": "Richard", "orcid": "0000-0002-7962-5446" }, { "family_name": "Nakajima", "given_name": "Hiroshi", "orcid": "0000-0001-6988-3938" }, { "family_name": "Nakazawa", "given_name": "Kazuhiro", "orcid": "0000-0003-2930-350X" }, { "family_name": "Ness", "given_name": "Jan-Uwe" }, { "family_name": "Nobukawa", "given_name": "Kumiko", "orcid": "0000-0002-0726-7862" }, { "family_name": "Nobukawa", "given_name": "Masayoshi", "orcid": "0000-0003-1130-5363" }, { "family_name": "Noda", "given_name": "Hirofumi", "orcid": "0000-0001-6020-517X" }, { "family_name": "Odaka", "given_name": "Hirokazu" }, { "family_name": "Ogawa", "given_name": "Shoji", "orcid": "0000-0002-5701-0811" }, { "family_name": "Ogorzalek", "given_name": "Anna", "orcid": "0000-0003-4504-2557" }, { "family_name": "Okajima", "given_name": "Takashi", "orcid": "0000-0002-6054-3432" }, { "family_name": "Ota", "given_name": "Naomi", "orcid": "0000-0002-2784-3652" }, { "family_name": "Paltani", "given_name": "Stephane", "orcid": "0000-0002-8108-9179" }, { "family_name": "Petre", "given_name": "Robert", "orcid": "0000-0003-3850-2041" }, { "family_name": "Plucinsky", "given_name": "Paul", "orcid": "0000-0003-1415-5823" }, { "family_name": "Porter", "given_name": "Frederick Scott", "orcid": "0000-0002-6374-1119" }, { "family_name": "Pottschmidt", "given_name": "Katja", "orcid": "0000-0002-4656-6881" }, { "family_name": "Sato", "given_name": "Kosuke", "orcid": "0000-0001-5774-1633" }, { "family_name": "Sato", "given_name": "Toshiki" }, { "family_name": "Sawada", "given_name": "Makoto", "orcid": "0000-0003-2008-6887" }, { "family_name": "Seta", "given_name": "Hiromi" }, { "family_name": "Shidatsu", "given_name": "Megumi", "orcid": "0000-0001-8195-6546" }, { "family_name": "Shimoda", "given_name": "Jiro", "orcid": "0000-0003-3383-2279" }, { "family_name": "Simionescu", "given_name": "Aurora", "orcid": "0000-0002-9714-3862" }, { "family_name": "Smith", "given_name": "Randall", "orcid": "0000-0003-4284-4167" }, { "family_name": "Suzuki", "given_name": "Hiromasa", "orcid": "0000-0002-8152-6172" }, { "family_name": "Szymkowiak", "given_name": "Andrew", "orcid": "0000-0002-4974-687X" }, { "family_name": "Takahashi", "given_name": "Hiromitsu", "orcid": "0000-0001-6314-5897" }, { "family_name": "Takeo", "given_name": "Mai" }, { "family_name": "Tamagawa", "given_name": "Toru" }, { "family_name": "Tamura", "given_name": "Keisuke" }, { "family_name": "Tanaka", "given_name": "Takaaki", "orcid": "0000-0002-4383-0368" }, { "family_name": "Tanimoto", "given_name": "Atsushi", "orcid": "0000-0002-0114-5581" }, { "family_name": "Tashiro", "given_name": "Makoto", "orcid": "0000-0002-5097-1257" }, { "family_name": "Terada", "given_name": "Yukikatsu", "orcid": "0000-0002-2359-1857" }, { "family_name": "Terashima", "given_name": "Yuichi", "orcid": "0000-0003-1780-5481" }, { "family_name": "Tsuboi", "given_name": "Yohko", "orcid": "0000-0001-9943-0024" }, { "family_name": "Tsujimoto", "given_name": "Masahiro", "orcid": "0000-0002-9184-5556" }, { "family_name": "Tsunemi", "given_name": "Hiroshi" }, { "family_name": "Tsuru", "given_name": "Takeshi G", "orcid": "0000-0002-5504-4903" }, { "family_name": "Uchida", "given_name": "Hiroyuki", "orcid": "0000-0003-1518-2188" }, { "family_name": "Uchida", "given_name": "Nagomi", "orcid": "0000-0002-5641-745X" }, { "family_name": "Uchida", "given_name": "Yuusuke", "orcid": "0000-0002-7962-4136" }, { "family_name": "Uchiyama", "given_name": "Hideki", "orcid": "0000-0003-4580-4021" }, { "family_name": "Ueda", "given_name": "Shutaro" }, { "family_name": "Ueda", "given_name": "Yoshihiro", "orcid": "0000-0001-7821-6715" }, { "family_name": "Uno", "given_name": "Shinichiro" }, { "family_name": "Vink", "given_name": "Jacco", "orcid": "0000-0002-4708-4219" }, { "family_name": "Watanabe", "given_name": "Shin", "orcid": "0000-0003-0441-7404" }, { "family_name": "Williams", "given_name": "Brian J", "orcid": "0000-0003-2063-381X" }, { "family_name": "Yamada", "given_name": "Satoshi", "orcid": "0000-0002-9754-3081" }, { "family_name": "Yamada", "given_name": "Shinya", "orcid": "0000-0003-4808-893X" }, { "family_name": "Yamaguchi", "given_name": "Hiroya", "orcid": "0000-0002-5092-6085" }, { "family_name": "Yamaoka", "given_name": "Kazutaka", "orcid": "0000-0003-3841-0980" }, { "family_name": "Yamasaki", "given_name": "Noriko", "orcid": "0000-0003-4885-5537" }, { "family_name": "Yamauchi", "given_name": "Makoto", "orcid": "0000-0003-1100-1423" }, { "family_name": "Yamauchi", "given_name": "Shigeo" }, { "family_name": "Yaqoob", "given_name": "Tahir" }, { "family_name": "Yoneyama", "given_name": "Tomokage", "orcid": "0000-0002-2683-6856" }, { "family_name": "Yoshida", "given_name": "Tessei" }, { "family_name": "Yukita", "given_name": "Mihoko", "orcid": "0000-0001-6366-3459" }, { "family_name": "Zhuravleva", "given_name": "Irina", "orcid": "0000-0001-7630-8085" }, { "family_name": "Miceli", "given_name": "Marco", "orcid": "0000-0003-0876-8391" }, { "family_name": "Sapienza", "given_name": "Vincenzo", "orcid": "0000-0002-6045-136X" }, { "literal": "XRISM Collaboration" } ], "abstract": "

We present an analysis of high-resolution spectra from the shock-heated plasmas in SN 1987A, based on an observation using the Resolve instrument onboard the X-Ray Imaging and Spectroscopy Mission (XRISM). The 1.7–10 keV Resolve spectra are accurately represented by a single-component, plane-parallel shock plasma model, with a temperature of 2.84_(-0.08)^(+0.09) keV and an ionization parameter of 2.64_(-0.45)^(+0.58) × 10¹¹ s cm\u207b³, The Resolve spectra are also well reproduced by the 3D magneto-hydrodynamic simulation presented by Orlando et al. (2020, A&A, 636, A22) suggesting substantial contribution from the ejecta. The metal abundances obtained with Resolve align with the Large Magellanic Cloud value, indicating that the X-rays in 2024 originate from \"non-metal-rich\" shock-heated ejecta and the reverse shock has not reached the inner metal-rich region of ejecta. Doppler widths of the atomic lines from Si, S, and Fe correspond to velocities of 1500–1700 km s\u207b¹, where the thermal broadening effects in this non-metal-rich plasma are negligible. Therefore, the line broadening seen in Resolve spectra is determined by the large bulk motion of ejecta. For reference, we determined a 90% upper limit on non-thermal emission from a pulsar wind nebula at 4.3 x 10\u207b¹³ erg cm\u207b² s\u207b¹ in the 2–10 keV range, aligning with NuSTAR findings by Greco et al. (2022, ApJ, 931, 132). Additionally, we searched for the \u2074\u2074Sc K line feature and found a 1σ upper limit of 1.0 x 10\u207b\u2076 photons cm\u207b² s\u207b¹, which translates to an initial \u2074\u2074Ti mass of approximately 2 x 10\u207b\u2074 M\u2299, consistent with previous X-ray to soft gamma-ray observations (Boggs et al. 2015, Science, 348, 670; Grebenev et al. 2012, Nature, 490, 373; Leising 2006, ApJ, 651, 1019).

", "doi": "10.1093/pasj/psaf056", "issn": "0004-6264", "publisher": "Oxford University Press (OUP)", "publication": "Publications of the Astronomical Society of Japan", "publication_date": "2025-09", "series_number": "S1", "volume": "77", "issue": "S1", "pages": "S193-S208" }, { "id": "authors:c8774-ww370", "collection": "authors", "collection_id": "c8774-ww370", "cite_using_url": "https://authors.library.caltech.edu/records/c8774-ww370", "type": "article", "title": "X-Ray Reflection Spectroscopy with Improved Calculations of the Emission Angle", "author": [ { "family_name": "Huang", "given_name": "Yimin", "orcid": "0009-0008-3299-9185" }, { "family_name": "Liu", "given_name": "Honghui", "orcid": "0000-0003-2845-1009" }, { "family_name": "Mirzaev", "given_name": "Temurbek", "orcid": "0000-0002-9337-4612" }, { "family_name": "Fan", "given_name": "Ningyue", "orcid": "0009-0009-2549-1161" }, { "family_name": "Bambi", "given_name": "Cosimo", "orcid": "0000-0002-3180-9502" }, { "family_name": "Zhang", "given_name": "Zuobin", "orcid": "0000-0003-0847-1299" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Ingram", "given_name": "Adam", "orcid": "0000-0002-5311-9078" }, { "family_name": "Jiang", "given_name": "Jiachen", "orcid": "0000-0002-9639-4352" }, { "family_name": "Mastroserio", "given_name": "Guglielmo", "orcid": "0000-0003-4216-7936" }, { "family_name": "Riaz", "given_name": "Shafqat" }, { "family_name": "Shashank", "given_name": "Swarnim", "orcid": "0000-0003-3402-7212" } ], "abstract": "

The reflection spectrum produced by a cold medium illuminated by X-ray photons is not isotropic and its shape depends on the emission angle. In the reflection spectrum of an accretion disk of a black hole, the value of the emission angle changes over the disk and, in general, is different from the value of the inclination angle of the disk because of the light bending in the strong gravitational field of the black hole. Current reflection models make some approximations, as calculating a reflection spectrum taking the correct emission angle at every point of the disk into account would be too time-consuming and make the model too slow to analyze observations. In a recent paper, we showed that these approximations are unsuitable to fit high-quality black hole spectra expected from the next generation of X-ray missions. Here, we present a reflection model with improved calculations of the emission angle that solves this problem.

", "doi": "10.3847/1538-4357/adf111", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2025-08-20", "series_number": "2", "volume": "989", "issue": "2", "pages": "168" }, { "id": "authors:jhe77-pnj16", "collection": "authors", "collection_id": "jhe77-pnj16", "cite_using_url": "https://authors.library.caltech.edu/records/jhe77-pnj16", "type": "article", "title": "The nature of the X-ray binary transient MAXI J1834\u2013021: Clues from its first observed outburst", "author": [ { "family_name": "Manca", "given_name": "A.", "orcid": "0009-0001-2063-4719" }, { "family_name": "Marino", "given_name": "A.", "orcid": "0000-0001-5674-4664" }, { "family_name": "Borghese", "given_name": "A.", "orcid": "0000-0001-8785-5922" }, { "family_name": "Coti Zelati", "given_name": "F.", "orcid": "0000-0001-7611-1581" }, { "family_name": "Mastroserio", "given_name": "G.", "orcid": "0000-0003-4216-7936" }, { "family_name": "Sanna", "given_name": "A.", "orcid": "0000-0002-0118-2649" }, { "family_name": "Homan", "given_name": "J.", "orcid": "0000-0001-8371-2713" }, { "family_name": "Connors", "given_name": "R. M. T.", "orcid": "0000-0002-8908-759X" }, { "family_name": "Del Santo", "given_name": "M.", "orcid": "0000-0002-1793-1050" }, { "family_name": "Armas Padilla", "given_name": "M.", "orcid": "0000-0002-4344-7334" }, { "family_name": "Mu\u00f1oz-Darias", "given_name": "T.", "orcid": "0000-0002-3348-4035" }, { "family_name": "Di Salvo", "given_name": "T.", "orcid": "0000-0002-3220-6375" }, { "family_name": "Rea", "given_name": "N.", "orcid": "0000-0003-2177-6388" }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Riggio", "given_name": "A.", "orcid": "0000-0002-6145-9224" }, { "family_name": "Baglio", "given_name": "M. C.", "orcid": "0000-0003-1285-4057" }, { "family_name": "Burderi", "given_name": "L.", "orcid": "0000-0001-5458-891X" } ], "abstract": "

MAXI J1834–021 is a new X-ray transient discovered in February 2023. We analysed the spectral and timing properties of MAXI J1834–021 using NICER, NuSTAR and Swift data collected between March and October 2023. The light curve showed a main peak followed by a second activity phase. Most of the spectra extracted from individual NICER observations could be adequately fit with a Comptonisation component alone, while some required an additional thermal component. The spectral evolution is consistent with a softening trend as the source becomes brighter in X-rays. We also analysed the broadband spectrum by combining data from simultaneous NICER and NuSTAR observations on March 10, 2023. This spectrum can be fitted with a disc component having an inner radius temperature of kTin∼0.4 keV and a Comptonisation component with a power-law photon index of Γ∼1.8. By including a reflection component in the modelling, we obtained a 3σ upper limit for the inner disc radius of 11.4 gravitational radii. We also detected a quasi-periodic oscillation (QPO), whose central frequency varies with time (from 2 Hz to ∼0.9 Hz), and anti-correlates with the hardness ratio. Based on the observed spectral-timing properties, MAXI J1834–021 can be classified as a low-mass X-ray binary in outburst. However, we cannot draw a definitive conclusion about the nature of the accreting compact object, which could currently be a black hole or a neutron star.

", "doi": "10.1051/0004-6361/202451513", "issn": "0004-6361", "publisher": "EDP Sciences", "publication": "Astronomy and Astrophysics", "publication_date": "2025-07", "volume": "699", "pages": "A114" }, { "id": "authors:5ck7n-nfy18", "collection": "authors", "collection_id": "5ck7n-nfy18", "cite_using_url": "https://authors.library.caltech.edu/records/5ck7n-nfy18", "type": "article", "title": "Structured ionized winds shooting out from a quasar at relativistic speeds", "author": [ { "family_name": "Audard", "given_name": "Marc", "orcid": "0000-0003-4721-034X" }, { "family_name": "Awaki", "given_name": "Hisamitsu" }, { "family_name": "Ballhausen", "given_name": "Ralf" }, { "family_name": "Bamba", "given_name": "Aya", "orcid": "0000-0003-0890-4920" }, { "family_name": "Behar", "given_name": "Ehud", "orcid": "0000-0001-9735-4873" }, { "family_name": "Boissay-Malaquin", "given_name": "Rozenn", "orcid": "0000-0003-2704-599X" }, { "family_name": "Brenneman", "given_name": "Laura" }, { "family_name": "Brown", "given_name": "Gregory V." }, { "family_name": "Corrales", "given_name": "Lia" }, { "family_name": "Costantini", "given_name": "Elisa", "orcid": "0000-0001-8470-749X" }, { "family_name": "Cumbee", "given_name": "Renata", "orcid": "0000-0001-9894-295X" }, { "family_name": "Trigo", "given_name": "Mar\u00eda D\u00edaz", "orcid": "0000-0001-7796-4279" }, { "family_name": "Done", "given_name": "Chris", "orcid": "0000-0002-1065-7239" }, { "family_name": "Dotani", "given_name": "Tadayasu" }, { "family_name": "Ebisawa", "given_name": "Ken" }, { "family_name": "Eckart", "given_name": "Megan", "orcid": "0000-0003-3894-5889" }, { "family_name": "Eckert", "given_name": "Dominique" }, { "family_name": "Enoto", "given_name": "Teruaki" }, { "family_name": "Eguchi", "given_name": "Satoshi", "orcid": "0000-0003-2814-9336" }, { "family_name": "Ezoe", "given_name": "Yuichiro" }, { "family_name": "Foster", "given_name": "Adam" }, { "family_name": "Fujimoto", "given_name": "Ryuichi", "orcid": "0000-0002-2374-7073" }, { "family_name": "Fujita", "given_name": "Yutaka", "orcid": "0000-0003-0058-9719" }, { "family_name": "Fukazawa", "given_name": "Yasushi" }, { "family_name": "Fukushima", "given_name": "Kotaro", "orcid": "0000-0001-8055-7113" }, { "family_name": "Furuzawa", "given_name": "Akihiro" }, { "family_name": "Gallo", "given_name": "Luigi" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Gu", "given_name": "Liyi" }, { "family_name": "Guainazzi", "given_name": "Matteo" }, { "family_name": "Hagino", "given_name": "Kouichi", "orcid": "0000-0003-4235-5304" }, { "family_name": "Hamaguchi", "given_name": "Kenji", "orcid": "0000-0001-7515-2779" }, { "family_name": "Hatsukade", "given_name": "Isamu" }, { "family_name": "Hayashi", "given_name": "Katsuhiro" }, { "family_name": "Hayashi", "given_name": "Takayuki", "orcid": "0000-0001-6665-2499" }, { "family_name": "Hell", "given_name": "Natalie", "orcid": "0000-0003-3057-1536" }, { "family_name": "Hodges-Kluck", "given_name": "Edmund" }, { "family_name": "Hornschemeier", "given_name": "Ann" }, { "family_name": "Ichinohe", "given_name": "Yuto", "orcid": "0000-0002-6102-1441" }, { "family_name": "Ishida", "given_name": "Manabu" }, { "family_name": "Ishikawa", "given_name": "Kumi" }, { "family_name": "Ishisaki", "given_name": "Yoshitaka" }, { "family_name": "Kaastra", "given_name": "Jelle", "orcid": "0000-0001-5540-2822" }, { "family_name": "Kallman", "given_name": "Timothy" }, { "family_name": "Kara", "given_name": "Erin", "orcid": "0000-0003-0172-0854" }, { "family_name": "Katsuda", "given_name": "Satoru" }, { "family_name": "Kanemaru", "given_name": "Yoshiaki", "orcid": "0000-0002-4541-1044" }, { "family_name": "Kelley", "given_name": "Richard" }, { "family_name": "Kilbourne", "given_name": "Caroline" }, { "family_name": "Kitamoto", "given_name": "Shunji" }, { "family_name": "Kobayashi", "given_name": "Shogo" }, { "family_name": "Kohmura", "given_name": "Takayoshi", "orcid": "0000-0003-4403-4512" }, { "family_name": "Kubota", "given_name": "Aya" }, { "family_name": "Leutenegger", "given_name": "Maurice", "orcid": "0000-0002-3331-7595" }, { "family_name": "Loewenstein", "given_name": "Michael", "orcid": "0000-0002-1661-4029" }, { "family_name": "Maeda", "given_name": "Yoshitomo" }, { "family_name": "Markevitch", "given_name": "Maxim" }, { "family_name": "Matsumoto", "given_name": "Hironori" }, { "family_name": "Matsushita", "given_name": "Kyoko" }, { "family_name": "McCammon", "given_name": "Dan", "orcid": "0000-0001-5170-4567" }, { "family_name": "McNamara", "given_name": "Brian" }, { "family_name": "Mernier", "given_name": "Fran\u00e7ois" }, { "family_name": "Miller", "given_name": "Eric D.", "orcid": "0000-0002-3031-2326" }, { "family_name": "Miller", "given_name": "Jon M.", "orcid": "0000-0003-2869-7682" }, { "family_name": "Mitsuishi", "given_name": "Ikuyuki", "orcid": "0000-0002-9901-233X" }, { "family_name": "Mizumoto", "given_name": "Misaki", "orcid": "0000-0003-2161-0361" }, { "family_name": "Mizuno", "given_name": "Tsunefumi", "orcid": "0000-0001-7263-0296" }, { "family_name": "Mori", "given_name": "Koji", "orcid": "0000-0002-0018-0369" }, { "family_name": "Mukai", "given_name": "Koji", "orcid": "0000-0002-8286-8094" }, { "family_name": "Murakami", "given_name": "Hiroshi" }, { "family_name": "Mushotzky", "given_name": "Richard", "orcid": "0000-0002-7962-5446" }, { "family_name": "Nakajima", "given_name": "Hiroshi" }, { "family_name": "Nakazawa", "given_name": "Kazuhiro" }, { "family_name": "Ness", "given_name": "Jan-Uwe" }, { "family_name": "Nobukawa", "given_name": "Kumiko" }, { "family_name": "Nobukawa", "given_name": "Masayoshi" }, { "family_name": "Noda", "given_name": "Hirofumi" }, { "family_name": "Odaka", "given_name": "Hirokazu" }, { "family_name": "Ogawa", "given_name": "Shoji" }, { "family_name": "Ogorzalek", "given_name": "Anna" }, { "family_name": "Okajima", "given_name": "Takashi", "orcid": "0000-0002-6054-3432" }, { "family_name": "Ota", "given_name": "Naomi", "orcid": "0000-0002-2784-3652" }, { "family_name": "Paltani", "given_name": "Stephane" }, { "family_name": "Petre", "given_name": "Robert" }, { "family_name": "Plucinsky", "given_name": "Paul" }, { "family_name": "Porter", "given_name": "Frederick Scott", "orcid": "0000-0002-6374-1119" }, { "family_name": "Pottschmidt", "given_name": "Katja", "orcid": "0000-0002-4656-6881" }, { "family_name": "Sato", "given_name": "Kosuke", "orcid": "0000-0001-5774-1633" }, { "family_name": "Sato", "given_name": "Toshiki" }, { "family_name": "Sawada", "given_name": "Makoto" }, { "family_name": "Seta", "given_name": "Hiromi" }, { "family_name": "Shidatsu", "given_name": "Megumi", "orcid": "0000-0001-8195-6546" }, { "family_name": "Simionescu", "given_name": "Aurora", "orcid": "0000-0002-9714-3862" }, { "family_name": "Smith", "given_name": "Randall", "orcid": "0000-0003-4284-4167" }, { "family_name": "Suzuki", "given_name": "Hiromasa" }, { "family_name": "Szymkowiak", "given_name": "Andrew" }, { "family_name": "Takahashi", "given_name": "Hiromitsu", "orcid": "0000-0001-6314-5897" }, { "family_name": "Takeo", "given_name": "Mai" }, { "family_name": "Tamagawa", "given_name": "Toru", "orcid": "0000-0002-8801-6263" }, { "family_name": "Tamura", "given_name": "Keisuke", "orcid": "0000-0002-6677-3917" }, { "family_name": "Tanaka", "given_name": "Takaaki", "orcid": "0000-0002-4383-0368" }, { "family_name": "Tanimoto", "given_name": "Atsushi" }, { "family_name": "Tashiro", "given_name": "Makoto", "orcid": "0000-0002-5097-1257" }, { "family_name": "Terada", "given_name": "Yukikatsu", "orcid": "0000-0002-2359-1857" }, { "family_name": "Terashima", "given_name": "Yuichi" }, { "family_name": "Tsuboi", "given_name": "Yohko" }, { "family_name": "Tsujimoto", "given_name": "Masahiro" }, { "family_name": "Tsunemi", "given_name": "Hiroshi" }, { "family_name": "Tsuru", "given_name": "Takeshi G.", "orcid": "0000-0002-5504-4903" }, { "family_name": "Uchida", "given_name": "Hiroyuki" }, { "family_name": "Uchida", "given_name": "Nagomi" }, { "family_name": "Uchida", "given_name": "Yuusuke", "orcid": "0000-0002-7962-4136" }, { "family_name": "Uchiyama", "given_name": "Hideki", "orcid": "0000-0003-4580-4021" }, { "family_name": "Ueda", "given_name": "Yoshihiro" }, { "family_name": "Uno", "given_name": "Shinichiro" }, { "family_name": "Vink", "given_name": "Jacco", "orcid": "0000-0002-4708-4219" }, { "family_name": "Watanabe", "given_name": "Shin", "orcid": "0000-0003-0441-7404" }, { "family_name": "Williams", "given_name": "Brian J.", "orcid": "0000-0003-2063-381X" }, { "family_name": "Yamada", "given_name": "Satoshi" }, { "family_name": "Yamada", "given_name": "Shinya", "orcid": "0000-0003-4808-893X" }, { "family_name": "Yamaguchi", "given_name": "Hiroya" }, { "family_name": "Yamaoka", "given_name": "Kazutaka" }, { "family_name": "Yamasaki", "given_name": "Noriko", "orcid": "0000-0003-4885-5537" }, { "family_name": "Yamauchi", "given_name": "Makoto", "orcid": "0000-0003-1100-1423" }, { "family_name": "Yamauchi", "given_name": "Shigeo" }, { "family_name": "Yaqoob", "given_name": "Tahir" }, { "family_name": "Yoneyama", "given_name": "Tomokage" }, { "family_name": "Yoshida", "given_name": "Tessei" }, { "family_name": "Yukita", "given_name": "Mihoko" }, { "family_name": "Zhuravleva", "given_name": "Irina", "orcid": "0000-0001-7630-8085" }, { "family_name": "Braito", "given_name": "Valentina" }, { "family_name": "Cond\u00f2", "given_name": "Pierpaolo", "orcid": "0009-0005-9183-8662" }, { "family_name": "Fukumura", "given_name": "Keigo", "orcid": "0000-0001-5709-7606" }, { "family_name": "Gonzalez", "given_name": "Adam", "orcid": "0000-0003-3678-5033" }, { "family_name": "Luminari", "given_name": "Alfredo" }, { "family_name": "Miyamoto", "given_name": "Aiko" }, { "family_name": "Mizukawa", "given_name": "Ryuki" }, { "family_name": "Reeves", "given_name": "James", "orcid": "0000-0002-0982-0561" }, { "family_name": "Sato", "given_name": "Riki", "orcid": "0009-0002-6943-8169" }, { "family_name": "Tombesi", "given_name": "Francesco", "orcid": "0000-0002-6562-8654" }, { "family_name": "Xu", "given_name": "Yerong" }, { "literal": "XRISM collaboration" } ], "abstract": "Evidence indicates that supermassive black holes (SMBHs) exist at the centres of most galaxies. Their mass correlates with the galactic bulge mass1, suggesting a coevolution with their host galaxies2, most likely through powerful winds3. X-ray observations have detected highly ionized winds outflowing at sub-relativistic speeds from the accretion disks around SMBHs4,5. However, the limited spectral resolution of present X-ray instruments has left the physical structure and location of the winds poorly understood, hindering accurate estimates of their kinetic power6,7. Here the first X-Ray Imaging and Spectroscopy Mission (XRISM) observation of the luminous quasar PDS\u2009456 is reported. The high-resolution spectrometer Resolve aboard XRISM enabled the discovery of five discrete velocity components outflowing at 20\u201330% of the speed of light. This demonstrates that the wind structure is highly inhomogeneous, which probably consists of up to a million clumps. The mass outflow rate is estimated to be 60\u2013300 solar masses per year, with the wind kinetic power exceeding the Eddington luminosity limit. Compared with the galaxy-scale outflows, the kinetic power is more than three orders of magnitude larger, whereas the momentum flux is ten times larger. These estimates disfavour both energy-driven and momentum-driven outflow models. This suggests that such wind activity occurs in less than 10% of the quasar phase and/or that its energy/momentum is not efficiently transferred to the galaxy-scale outflows owing to the clumpiness of the wind and the interstellar medium.", "doi": "10.1038/s41586-025-08968-2", "issn": "0028-0836", "publisher": "Nature Publishing Group", "publication": "Nature", "publication_date": "2025-05-29", "volume": "641", "pages": "1132-1136" }, { "id": "authors:fqmdb-vw367", "collection": "authors", "collection_id": "fqmdb-vw367", "cite_using_url": "https://authors.library.caltech.edu/records/fqmdb-vw367", "type": "article", "title": "XRISM Forecast for the Coma Cluster: Stormy, with a Steep Power Spectrum", "author": [ { "family_name": "Audard", "given_name": "Marc", "orcid": "0000-0003-4721-034X" }, { "family_name": "Awaki", "given_name": "Hisamitsu" }, { "family_name": "Ballhausen", "given_name": "Ralf", "orcid": "0000-0002-1118-8470" }, { "family_name": "Bamba", "given_name": "Aya", "orcid": "0000-0003-0890-4920" }, { "family_name": "Behar", "given_name": "Ehud", "orcid": "0000-0001-9735-4873" }, { "family_name": "Boissay-Malaquin", "given_name": "Rozenn", "orcid": "0000-0003-2704-599X" }, { "family_name": "Brenneman", "given_name": "Laura", "orcid": "0000-0003-2663-1954" }, { "family_name": "Brown", "given_name": "Gregory V.", "orcid": "0000-0001-6338-9445" }, { "family_name": "Corrales", "given_name": "Lia", "orcid": "0000-0002-5466-3817" }, { "family_name": "Costantini", "given_name": "Elisa", "orcid": "0000-0001-8470-749X" }, { "family_name": "Cumbee", "given_name": "Renata", "orcid": "0000-0001-9894-295X" }, { "family_name": "Diaz Trigo", "given_name": "Maria", "orcid": "0000-0001-7796-4279" }, { "family_name": "Done", "given_name": "Chris", "orcid": "0000-0002-1065-7239" }, { "family_name": "Dotani", "given_name": "Tadayasu" }, { "family_name": "Ebisawa", "given_name": "Ken", "orcid": "0000-0002-5352-7178" }, { "family_name": "Eckart", "given_name": "Megan E.", "orcid": "0000-0003-3894-5889" }, { "family_name": "Eckert", "given_name": "Dominique", "orcid": "0000-0001-7917-3892" }, { "family_name": "Eguchi", "given_name": "Satoshi", "orcid": "0000-0003-2814-9336" }, { "family_name": "Enoto", "given_name": "Teruaki", "orcid": "0000-0003-1244-3100" }, { "family_name": "Ezoe", "given_name": "Yuichiro" }, { "family_name": "Foster", "given_name": "Adam", "orcid": "0000-0003-3462-8886" }, { "family_name": "Fujimoto", "given_name": "Ryuichi", "orcid": "0000-0002-2374-7073" }, { "family_name": "Fujita", "given_name": "Yutaka", "orcid": "0000-0003-0058-9719" }, { "family_name": "Fukazawa", "given_name": "Yasushi", "orcid": "0000-0002-0921-8837" }, { "family_name": "Fukushima", "given_name": "Kotaro", "orcid": "0000-0001-8055-7113" }, { "family_name": "Furuzawa", "given_name": "Akihiro" }, { "family_name": "Gallo", "given_name": "Luigi", "orcid": "0009-0006-4968-7108" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Gu", "given_name": "Liyi", "orcid": "0000-0001-9911-7038" }, { "family_name": "Guainazzi", "given_name": "Matteo", "orcid": "0000-0002-1094-3147" }, { "family_name": "Hagino", "given_name": "Kouichi", "orcid": "0000-0003-4235-5304" }, { "family_name": "Hamaguchi", "given_name": "Kenji", "orcid": "0000-0001-7515-2779" }, { "family_name": "Hatsukade", "given_name": "Isamu", "orcid": "0000-0003-3518-3049" }, { "family_name": "Hayashi", "given_name": "Katsuhiro", "orcid": "0000-0001-6922-6583" }, { "family_name": "Hayashi", "given_name": "Takayuki", "orcid": "0000-0001-6665-2499" }, { "family_name": "Hell", "given_name": "Natalie", "orcid": "0000-0003-3057-1536" }, { "family_name": "Hodges-Kluck", "given_name": "Edmund", "orcid": "0000-0002-2397-206X" }, { "family_name": "Hornschemeier", "given_name": "Ann", "orcid": "0000-0001-8667-2681" }, { "family_name": "Ichinohe", "given_name": "Yuto", "orcid": "0000-0002-6102-1441" }, { "family_name": "Ishi", "given_name": "Daiki" }, { "family_name": "Ishida", "given_name": "Manabu" }, { "family_name": "Ishikawa", "given_name": "Kumi" }, { "family_name": "Ishisaki", "given_name": "Yoshitaka" }, { "family_name": "Kaastra", "given_name": "Jelle", "orcid": "0000-0001-5540-2822" }, { "family_name": "Kallman", "given_name": "Timothy" }, { "family_name": "Kara", "given_name": "Erin", "orcid": "0000-0003-0172-0854" }, { "family_name": "Katsuda", "given_name": "Satoru", "orcid": "0000-0002-1104-7205" }, { "family_name": "Kanemaru", "given_name": "Yoshiaki", "orcid": "0000-0002-4541-1044" }, { "family_name": "Kelley", "given_name": "Richard", "orcid": "0009-0007-2283-3336" }, { "family_name": "Kilbourne", "given_name": "Caroline", "orcid": "0000-0001-9464-4103" }, { "family_name": "Kitamoto", "given_name": "Shunji", "orcid": "0000-0001-8948-7983" }, { "family_name": "Kobayashi", "given_name": "Shogo", "orcid": "0000-0001-7773-9266" }, { "family_name": "Kohmura", "given_name": "Takayoshi" }, { "family_name": "Kubota", "given_name": "Aya" }, { "family_name": "Leutenegger", "given_name": "Maurice", "orcid": "0000-0002-3331-7595" }, { "family_name": "Loewenstein", "given_name": "Michael", "orcid": "0000-0002-1661-4029" }, { "family_name": "Maeda", "given_name": "Yoshitomo", "orcid": "0000-0002-9099-5755" }, { "family_name": "Markevitch", "given_name": "Maxim" }, { "family_name": "Matsumoto", "given_name": "Hironori" }, { "family_name": "Matsushita", "given_name": "Kyoko", "orcid": "0000-0003-2907-0902" }, { "family_name": "McCammon", "given_name": "Dan", "orcid": "0000-0001-5170-4567" }, { "family_name": "McNamara", "given_name": "Brian" }, { "family_name": "Mernier", "given_name": "Fran\u00e7ois", "orcid": "0000-0002-7031-4772" }, { "family_name": "Miller", "given_name": "Eric D.", "orcid": "0000-0002-3031-2326" }, { "family_name": "Miller", "given_name": "Jon M.", "orcid": "0000-0003-2869-7682" }, { "family_name": "Mitsuishi", "given_name": "Ikuyuki", "orcid": "0000-0002-9901-233X" }, { "family_name": "Mizumoto", "given_name": "Misaki", "orcid": "0000-0003-2161-0361" }, { "family_name": "Mizuno", "given_name": "Tsunefumi", "orcid": "0000-0001-7263-0296" }, { "family_name": "Mori", "given_name": "Koji", "orcid": "0000-0002-0018-0369" }, { "family_name": "Mukai", "given_name": "Koji", "orcid": "0000-0002-8286-8094" }, { "family_name": "Murakami", "given_name": "Hiroshi" }, { "family_name": "Mushotzky", "given_name": "Richard", "orcid": "0000-0002-7962-5446" }, { "family_name": "Nakajima", "given_name": "Hiroshi", "orcid": "0000-0001-6988-3938" }, { "family_name": "Nakazawa", "given_name": "Kazuhiro", "orcid": "0000-0003-2930-350X" }, { "family_name": "Ness", "given_name": "Jan-Uwe" }, { "family_name": "Nobukawa", "given_name": "Kumiko", "orcid": "0000-0002-0726-7862" }, { "family_name": "Nobukawa", "given_name": "Masayoshi", "orcid": "0000-0003-1130-5363" }, { "family_name": "Noda", "given_name": "Hirofumi", "orcid": "0000-0001-6020-517X" }, { "family_name": "Odaka", "given_name": "Hirokazu" }, { "family_name": "Ogawa", "given_name": "Shoji", "orcid": "0000-0002-5701-0811" }, { "family_name": "Ogorza\u0142ek", "given_name": "Anna", "orcid": "0000-0003-4504-2557" }, { "family_name": "Okajima", "given_name": "Takashi", "orcid": "0000-0002-6054-3432" }, { "family_name": "Ota", "given_name": "Naomi", "orcid": "0000-0002-2784-3652" }, { "family_name": "Paltani", "given_name": "St\u00e9phane", "orcid": "0000-0002-8108-9179" }, { "family_name": "Petre", "given_name": "Robert", "orcid": "0000-0003-3850-2041" }, { "family_name": "Plucinsky", "given_name": "Paul", "orcid": "0000-0003-1415-5823" }, { "family_name": "Porter", "given_name": "Frederick S.", "orcid": "0000-0002-6374-1119" }, { "family_name": "Pottschmidt", "given_name": "Katja", "orcid": "0000-0002-4656-6881" }, { "family_name": "Sato", "given_name": "Kosuke" }, { "family_name": "Sato", "given_name": "Toshiki" }, { "family_name": "Sawada", "given_name": "Makoto", "orcid": "0000-0003-2008-6887" }, { "family_name": "Seta", "given_name": "Hiromi" }, { "family_name": "Shidatsu", "given_name": "Megumi", "orcid": "0000-0001-8195-6546" }, { "family_name": "Simionescu", "given_name": "Aurora", "orcid": "0000-0002-9714-3862" }, { "family_name": "Smith", "given_name": "Randall", "orcid": "0000-0003-4284-4167" }, { "family_name": "Suzuki", "given_name": "Hiromasa", "orcid": "0000-0002-8152-6172" }, { "family_name": "Szymkowiak", "given_name": "Andrew", "orcid": "0000-0002-4974-687X" }, { "family_name": "Takahashi", "given_name": "Hiromitsu", "orcid": "0000-0001-6314-5897" }, { "family_name": "Takeo", "given_name": "Mai" }, { "family_name": "Tamagawa", "given_name": "Toru", "orcid": "0000-0002-8801-6263" }, { "family_name": "Tamura", "given_name": "Keisuke" }, { "family_name": "Tanaka", "given_name": "Takaaki", "orcid": "0000-0002-4383-0368" }, { "family_name": "Tanimoto", "given_name": "Atsushi", "orcid": "0000-0002-0114-5581" }, { "family_name": "Tashiro", "given_name": "Makoto", "orcid": "0000-0002-5097-1257" }, { "family_name": "Terada", "given_name": "Yukikatsu", "orcid": "0000-0002-2359-1857" }, { "family_name": "Terashima", "given_name": "Yuichi", "orcid": "0000-0003-1780-5481" }, { "family_name": "Tsuboi", "given_name": "Yohko", "orcid": "0000-0001-9943-0024" }, { "family_name": "Tsujimoto", "given_name": "Masahiro", "orcid": "0000-0002-9184-5556" }, { "family_name": "Tsunemi", "given_name": "Hiroshi" }, { "family_name": "Tsuru", "given_name": "Takeshi", "orcid": "0000-0002-5504-4903" }, { "family_name": "T\u00fcmer", "given_name": "Ay\u015feg\u00fcl", "orcid": "0000-0002-3132-8776" }, { "family_name": "Uchida", "given_name": "Hiroyuki", "orcid": "0000-0003-1518-2188" }, { "family_name": "Uchida", "given_name": "Nagomi", "orcid": "0000-0002-5641-745X" }, { "family_name": "Uchida", "given_name": "Yuusuke", "orcid": "0000-0002-7962-4136" }, { "family_name": "Uchiyama", "given_name": "Hideki", "orcid": "0000-0003-4580-4021" }, { "family_name": "Ueda", "given_name": "Shutaro" }, { "family_name": "Ueda", "given_name": "Yoshihiro", "orcid": "0000-0001-7821-6715" }, { "family_name": "Uno", "given_name": "Shinichiro" }, { "family_name": "Vink", "given_name": "Jacco", "orcid": "0000-0002-4708-4219" }, { "family_name": "Watanabe", "given_name": "Shin", "orcid": "0000-0003-0441-7404" }, { "family_name": "Williams", "given_name": "Brian J.", "orcid": "0000-0003-2063-381X" }, { "family_name": "Yamada", "given_name": "Satoshi", "orcid": "0000-0002-9754-3081" }, { "family_name": "Yamada", "given_name": "Shinya", "orcid": "0000-0003-4808-893X" }, { "family_name": "Yamaguchi", "given_name": "Hiroya", "orcid": "0000-0002-5092-6085" }, { "family_name": "Yamaoka", "given_name": "Kazutaka", "orcid": "0000-0003-3841-0980" }, { "family_name": "Yamasaki", "given_name": "Noriko", "orcid": "0000-0003-4885-5537" }, { "family_name": "Yamauchi", "given_name": "Makoto", "orcid": "0000-0003-1100-1423" }, { "family_name": "Yamauchi", "given_name": "Shigeo" }, { "family_name": "Yaqoob", "given_name": "Tahir" }, { "family_name": "Yoneyama", "given_name": "Tomokage" }, { "family_name": "Yoshida", "given_name": "Tessei" }, { "family_name": "Yukita", "given_name": "Mihoko", "orcid": "0000-0001-6366-3459" }, { "family_name": "Zhuravleva", "given_name": "Irina", "orcid": "0000-0001-7630-8085" }, { "family_name": "Fabian", "given_name": "Andrew" }, { "family_name": "Nelson", "given_name": "Dylan", "orcid": "0000-0001-8421-5890" }, { "family_name": "Okabe", "given_name": "Nobuhiro", "orcid": "0000-0003-2898-0728" }, { "family_name": "Pillepich", "given_name": "Annalisa", "orcid": "0000-0003-1065-9274" }, { "family_name": "Potter", "given_name": "Cicely", "orcid": "0009-0003-7738-9173" }, { "family_name": "Regamey", "given_name": "Manon" }, { "family_name": "Sakai", "given_name": "Kosei" }, { "family_name": "Shishido", "given_name": "Mona", "orcid": "0009-0002-7226-5019" }, { "family_name": "Truong", "given_name": "Nhut" }, { "family_name": "Wik", "given_name": "Daniel R.", "orcid": "0000-0001-9110-2245" }, { "family_name": "ZuHone", "given_name": "John", "orcid": "0000-0003-3175-2347" }, { "literal": "XRISM Collaboration" } ], "abstract": "

The XRISM Resolve microcalorimeter array measured the velocities of hot intracluster gas at two positions in the Coma galaxy cluster: 3′×3′ squares at the center and at 6′ (170 kpc) to the south. We find the line-of-sight velocity dispersions in those regions to be σz = 208 ± 12 km s−1 and 202 ± 24 km s−1, respectively. The central value corresponds to a 3D Mach number of M = 0.24 ± 0.015 and a ratio of the kinetic pressure of small-scale motions to thermal pressure in the intracluster plasma of only 3.1% ± 0.4%, at the lower end of predictions from cosmological simulations for merging clusters like Coma, and similar to that observed in the cool core of the relaxed cluster A2029. Meanwhile, the gas in both regions exhibits high line-of-sight velocity differences from the mean velocity of the cluster galaxies, Δvz = 450 ± 15 km s−1 and 730 ± 30 km s−1, respectively. A small contribution from an additional gas velocity component, consistent with the cluster optical mean, is detected along a sight line near the cluster center. The combination of the observed velocity dispersions and bulk velocities is not described by a Kolmogorov velocity power spectrum of steady-state turbulence; instead, the data imply a much steeper effective slope (i.e., relatively more power at larger linear scales). This may indicate either a very large dissipation scale, resulting in the suppression of small-scale motions, or a transient dynamic state of the cluster, where large-scale gas flows generated by an ongoing merger have not yet cascaded down to small scales.

", "doi": "10.3847/2041-8213/add2f6", "issn": "2041-8205", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal Letters", "publication_date": "2025-05-20", "series_number": "1", "volume": "985", "issue": "1", "pages": "L20" }, { "id": "authors:e1jmm-rjn72", "collection": "authors", "collection_id": "e1jmm-rjn72", "cite_using_url": "https://authors.library.caltech.edu/records/e1jmm-rjn72", "type": "article", "title": "Frequency-resolved Time Lags due to X-Ray Disk Reprocessing in AGN", "author": [ { "family_name": "Panagiotou", "given_name": "Christos", "orcid": "0009-0001-9034-6261" }, { "family_name": "Papadakis", "given_name": "Iossif", "orcid": "0000-0001-6264-140X" }, { "family_name": "Kara", "given_name": "Erin", "orcid": "0000-0003-0172-0854" }, { "family_name": "Papoutsis", "given_name": "Marios" }, { "family_name": "Cackett", "given_name": "Edward M.", "orcid": "0000-0002-8294-9281" }, { "family_name": "Dov\u010diak", "given_name": "Michal", "orcid": "0000-0003-0079-1239" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Kammoun", "given_name": "Elias", "orcid": "0000-0002-0273-218X", "clpid": "Kammoun-Elias" }, { "family_name": "Lewin", "given_name": "Collin", "orcid": "0000-0002-8671-1190" } ], "abstract": "

Over the last years, a number of broadband reverberation mapping campaigns have been conducted to explore the short-term UV and optical variability of nearby AGN. Despite the extensive data collected, the origin of the observed variability is still debated in the literature. Frequency-resolved time lags offer a promising approach to distinguish between different scenarios as they probe variability on different timescales. In this study, we present the expected frequency-resolved lags resulting from X-ray reprocessing in the accretion disk. The predicted lags are found to feature a general shape that resembles that of observational measurements while exhibiting strong dependence on various physical parameters. Additionally, we compare our model predictions to observational data for the case of NGC 5548, concluding that the X-ray illumination of the disk can effectively account for the observed frequency-resolved lags and power spectra in a self-consistent way. To date, X-ray disk reprocessing is the only physical model that has successfully reproduced the observed multiwavelength variability, in both amplitude and time delays, across a range of temporal frequencies.

", "doi": "10.3847/1538-4357/adbf95", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2025-04-20", "series_number": "2", "volume": "983", "issue": "2", "pages": "132" }, { "id": "authors:s8g9r-h6x78", "collection": "authors", "collection_id": "s8g9r-h6x78", "cite_using_url": "https://authors.library.caltech.edu/records/s8g9r-h6x78", "type": "article", "title": "Reprocessing from Highly Ionized Gas in the Soft Spectral State of V4641 Sgr with NuSTAR", "author": [ { "family_name": "Connors", "given_name": "Riley M. T.", "orcid": "0000-0002-8908-759X" }, { "family_name": "Neilsen", "given_name": "Joey", "orcid": "0000-0002-8247-786X" }, { "family_name": "Shaw", "given_name": "Aarran W.", "orcid": "0000-0002-8808-520X" }, { "family_name": "Steiner", "given_name": "James F.", "orcid": "0000-0002-5872-6061" }, { "family_name": "Vincentelli", "given_name": "Federico", "orcid": "0000-0002-1481-1870" }, { "family_name": "Garcia", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Uttley", "given_name": "Phil", "orcid": "0000-0001-9355-961X" }, { "family_name": "Remillard", "given_name": "Ronald A.", "orcid": "0000-0003-4815-0481" }, { "family_name": "Mastroserio", "given_name": "Guglielmo", "orcid": "0000-0003-4216-7936" } ], "abstract": "

V4641 Sgr is a low-mass black hole X-ray binary system with somewhat puzzling spectral characteristics during its soft state. Recent high-resolution spectroscopic studies of V4641 Sgr have revealed strong ionized emission-line features in both the optical and X-ray bands, including P-Cygni signatures, and an unusually low soft-state luminosity, indicating that the central engine is obscured. Here, we present an analysis of five Nuclear Spectroscopic Telescope Array (NuSTAR) observations of V4641 Sgr taken during its recent outburst in 2021, when the source was in the soft state. We identify highly ionized Fe K emission lines—consistent with a combination of the near-neutral 6.4 keV Fe Kα line and the H-like and He-like Fe Kα and Fe Kβ transitions found at 6.7–7 keV and ∼8 keV—and find no evidence for strong relativistic broadening. The line fluxes correlate linearly with the observed disk continuum flux, implying a direct connection between the central engine and the reprocessing region. Most interestingly, all five spectra also show a persistent highly ionized Fe K continuum edge feature at ∼9 keV with a stable optical depth, which is likely smeared, implying a localized reprocessing zone. We find tentative supporting evidence for obscuration of the inner accretion disk based on its unusually low intrinsic luminosity, although the NuSTAR spectra do not require obscuration from cold, optically thick gas.

", "doi": "10.3847/1538-4357/adbbdb", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2025-04-10", "series_number": "1", "volume": "983", "issue": "1", "pages": "25" }, { "id": "authors:p5bed-mp537", "collection": "authors", "collection_id": "p5bed-mp537", "cite_using_url": "https://authors.library.caltech.edu/records/p5bed-mp537", "type": "article", "title": "Impact of the returning radiation on x-ray reflection spectroscopy measurements: The case of Galactic black holes", "author": [ { "family_name": "Huang", "given_name": "Kexin", "orcid": "0009-0008-0472-9022" }, { "family_name": "Liu", "given_name": "Honghui", "orcid": "0000-0003-2845-1009" }, { "family_name": "Bambi", "given_name": "Cosimo", "orcid": "0000-0002-3180-9502" }, { "family_name": "Garcia", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Zhang", "given_name": "Zuobin" } ], "abstract": "

The effect of the returning radiation has long been ignored in the analysis of the reflection spectra of Galactic black holes and active galactic nuclei and only recently has been implemented in the relxill package. Here we present a study on the impact of the returning radiation on the estimate of the parameters of Galactic black holes. We consider high-quality NuSTAR spectra of three Galactic black holes (GX 339–4, Swift J1658.2–4242, and MAXI J1535–571) and we fit the data with the lamppost model in the latest version of relxill, first without including the returning radiation and then including the returning radiation. We do not find any significant difference in the estimate of the parameters of these systems between the two cases, even if all three sources are fast-rotating black holes and for two sources the estimate of the height of the corona is very low, two ingredients that should maximize the effect of the returning radiation. We discuss our results and the approximations in relxill.

", "doi": "10.1103/physrevd.111.063025", "issn": "2470-0010", "publisher": "American Physical Society", "publication": "Physical Review D", "publication_date": "2025-03-10", "series_number": "6", "volume": "111", "issue": "6", "pages": "063025" }, { "id": "authors:wcd07-0bp41", "collection": "authors", "collection_id": "wcd07-0bp41", "cite_using_url": "https://authors.library.caltech.edu/records/wcd07-0bp41", "type": "article", "title": "Millihertz oscillations near the innermost orbit of a supermassive black hole", "author": [ { "family_name": "Masterson", "given_name": "Megan", "orcid": "0000-0003-4127-0739" }, { "family_name": "Kara", "given_name": "Erin", "orcid": "0000-0003-0172-0854" }, { "family_name": "Panagiotou", "given_name": "Christos", "orcid": "0009-0001-9034-6261" }, { "family_name": "Alston", "given_name": "William N.", "orcid": "0000-0003-2658-6559" }, { "family_name": "Chakraborty", "given_name": "Joheen" }, { "family_name": "Burdge", "given_name": "Kevin", "orcid": "0000-0002-7226-836X" }, { "family_name": "Ricci", "given_name": "Claudio" }, { "family_name": "Laha", "given_name": "Sibasish" }, { "family_name": "Arcavi", "given_name": "Iair", "orcid": "0000-0001-7090-4898" }, { "family_name": "Arcodia", "given_name": "Riccardo", "orcid": "0000-0003-4054-7978" }, { "family_name": "Cenko", "given_name": "S. Bradley", "orcid": "0000-0003-1673-970X" }, { "family_name": "Fabian", "given_name": "Andrew C.", "orcid": "0000-0002-9378-4072" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Giustini", "given_name": "Margherita" }, { "family_name": "Ingram", "given_name": "Adam", "orcid": "0000-0002-5311-9078" }, { "family_name": "Kosec", "given_name": "Peter", "orcid": "0000-0003-4511-8427" }, { "family_name": "Loewenstein", "given_name": "Michael", "orcid": "0000-0002-1661-4029" }, { "family_name": "Meyer", "given_name": "Eileen T.", "orcid": "0000-0002-7676-9962" }, { "family_name": "Miniutti", "given_name": "Giovanni", "orcid": "0000-0003-0707-4531" }, { "family_name": "Pinto", "given_name": "Ciro", "orcid": "0000-0003-2532-7379" }, { "family_name": "Remillard", "given_name": "Ronald A.", "orcid": "0000-0003-4815-0481" }, { "family_name": "Sadaula", "given_name": "Dev R." }, { "family_name": "Shuvo", "given_name": "Onic I.", "orcid": "0000-0003-4727-2209" }, { "family_name": "Trakhtenbrot", "given_name": "Benny", "orcid": "0000-0002-3683-7297" }, { "family_name": "Wang", "given_name": "Jingyi" } ], "abstract": "

Recent discoveries from time-domain surveys are defying our expectations for how matter accretes onto supermassive black holes (SMBHs). The increased rate of short-timescale, repetitive events around SMBHs, including the recently discovered quasi-periodic eruptions1, 2, 3, 4–5, are garnering further interest in stellar-mass companions around SMBHs and the progenitors to millihertz-frequency gravitational-wave events. Here we report the discovery of a highly significant millihertz quasi-periodic oscillation (QPO) in an actively accreting SMBH, 1ES 1927+654, which underwent a major optical, ultraviolet and X-ray outburst beginning in 20186,7. The QPO was detected in 2022 with a roughly 18-minute period, corresponding to coherent motion on a scale of less than 10 gravitational radii, much closer to the SMBH than typical quasi-periodic eruptions. The period decreased to 7.1 minutes over 2 years with a decelerating period evolution (P greater than zero). To our knowledge, this evolution has never been seen in SMBH QPOs or high-frequency QPOs in stellar-mass black holes. Models invoking orbital decay of a stellar-mass companion struggle to explain the period evolution without stable mass transfer to offset angular-momentum losses, and the lack of a direct analogue to stellar-mass black-hole QPOs means that many instability models cannot explain all of the observed properties of the QPO in 1ES 1927+654. Future X-ray monitoring will test these models, and if it is a stellar-mass orbiter, the Laser Interferometer Space Antenna (LISA) should detect its low-frequency gravitational-wave emission.

", "doi": "10.1038/s41586-024-08385-x", "issn": "0028-0836", "publisher": "Nature Publishing Group", "publication": "Nature", "publication_date": "2025-02-13", "volume": "638", "pages": "370-375" }, { "id": "authors:1v5y7-0kv77", "collection": "authors", "collection_id": "1v5y7-0kv77", "cite_using_url": "https://authors.library.caltech.edu/records/1v5y7-0kv77", "type": "article", "title": "About the accuracy of the relxill/relxill_nk models in view of the next generation of X-ray missions", "author": [ { "family_name": "Liu", "given_name": "Honghui", "orcid": "0000-0003-2845-1009" }, { "family_name": "Abdikamalov", "given_name": "Askar B." }, { "family_name": "Mirzaev", "given_name": "Temurbek", "orcid": "0000-0002-9337-4612" }, { "family_name": "Bambi", "given_name": "Cosimo", "orcid": "0000-0002-3180-9502" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048" }, { "family_name": "Garcia", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Zhang", "given_name": "Zuobin", "orcid": "0000-0003-0847-1299" } ], "abstract": "

X-ray reflection spectroscopy is a powerful tool to study the strong gravity region of black holes. The next generation of astrophysical X-ray missions promises to provide unprecedented high-quality data, which could permit us to get very precise measurements of the properties of the accretion flow and of the space–time geometry in the strong gravity region around these objects. In this work, we test the accuracy of the relativistic calculations of the reflection model relxill and of its extension to non-Kerr space–times relxill_nk in view of the next generation of X-ray missions. We simulate simultaneous observations with Athena/X-IFU and LAD of bright Galactic black holes with a precise and accurate ray-tracing code and we fit the simulated data with the latest versions of relline and relline_nk. While we always recover the correct input parameters, we find residuals in the fits when the emission from the inner part of the accretion disc is higher. Such residuals disappear if we increase the number of interpolation points on the disc in the integral of the transfer function. We also simulate full reflection spectra and find that the emission angle from the accretion disc should be treated properly in this case.

", "doi": "10.1093/mnras/stae2722", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2025-01", "series_number": "3", "volume": "536", "issue": "3", "pages": "2594-2602" }, { "id": "authors:0g4be-5jz54", "collection": "authors", "collection_id": "0g4be-5jz54", "cite_using_url": "https://authors.library.caltech.edu/records/0g4be-5jz54", "type": "article", "title": "Characterizing the Broadband Reflection Spectrum of MAXI J1803-298 during Its 2021 Outburst with NuSTAR and NICER", "author": [ { "family_name": "Adegoke", "given_name": "Oluwashina K.", "orcid": "0000-0002-5966-4210", "clpid": "Adegoke-Oluwashina-K" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Connors", "given_name": "Riley M. T.", "orcid": "0000-0002-8908-759X" }, { "family_name": "Ding", "given_name": "Yuanze", "orcid": "0000-0002-5770-2666", "clpid": "Ding-Yuanze" }, { "family_name": "Mastroserio", "given_name": "Guglielmo", "orcid": "0000-0003-4216-7936" }, { "family_name": "Steiner", "given_name": "James F.", "orcid": "0000-0002-5872-6061" }, { "family_name": "Ingram", "given_name": "Adam", "orcid": "0000-0002-5311-9078" }, { "family_name": "Harrison", "given_name": "Fiona A.", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" }, { "family_name": "Tomsick", "given_name": "John A.", "orcid": "0000-0001-5506-9855" }, { "family_name": "Kara", "given_name": "Erin", "orcid": "0000-0003-0172-0854" }, { "family_name": "Mehdipour", "given_name": "Missagh", "orcid": "0000-0002-4992-4664" }, { "family_name": "Fukumura", "given_name": "Keigo", "orcid": "0000-0001-5709-7606" }, { "family_name": "Stern", "given_name": "Daniel", "orcid": "0000-0003-2686-9241", "clpid": "Stern-D" }, { "family_name": "Ubach", "given_name": "Santiago", "orcid": "0000-0002-6159-5883" }, { "family_name": "Lucchini", "given_name": "Matteo", "orcid": "0000-0002-2235-3347" } ], "abstract": "

MAXI J1803-298 is a transient black hole candidate discovered in 2021 May during an outburst that lasted several months. Multiple X-ray observations reveal recurring \"dipping\" intervals in several of its light curves, particularly during the hard/intermediate states, with a typical recurrence period of ∼7 hr. We report analysis of four NuSTAR observations of the source, supplemented with NICER data where available, over the duration of the outburst evolution covering the hard, intermediate, and the soft states. Reflection spectroscopy reveals the black hole to be rapidly spinning (a * = 0.990 ± 0.001) with a near edge-on viewing angle (i = 70° ± 1°). Additionally, we show that the light-curve dips are caused by photoelectric absorption from a moderately ionized absorber whose origin is not fully understood, although it is likely linked to material from the companion star impacting the outer edges of the accretion disk. We further detect absorption lines in some of the spectra, potentially associated with Fe xxv and Fe xxvi, indicative of disk winds with moderate to extreme velocities. During the intermediate state and just before transitioning into the soft state, the source showed a sudden flux increase, which we found to be dominated by soft disk photons and consistent with the filling of the inner accretion disk, at the onset of state transition. In the soft state, we show that models of disk self-irradiation provide a better fit and a preferred explanation to the broadband reflection spectrum, consistent with previous studies of other accreting sources.

", "doi": "10.3847/1538-4357/ad82e9", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2024-12-10", "series_number": "1", "volume": "977", "issue": "1", "pages": "26" }, { "id": "authors:wctc2-f0071", "collection": "authors", "collection_id": "wctc2-f0071", "cite_using_url": "https://authors.library.caltech.edu/records/wctc2-f0071", "type": "article", "title": "Evidence for a shock-compressed magnetic field in the northwestern rim of Vela Jr. from X-ray polarimetry", "author": [ { "family_name": "Prokhorov", "given_name": "Dmitry A.", "orcid": "0000-0001-6511-4330" }, { "family_name": "Yang", "given_name": "Yi-Jung", "orcid": "0000-0001-9108-573X" }, { "family_name": "Ferrazzoli", "given_name": "Riccardo", "orcid": "0000-0003-1074-8605" }, { "family_name": "Vink", "given_name": "Jacco", "orcid": "0000-0002-4708-4219" }, { "family_name": "Slane", "given_name": "Patrick", "orcid": "0000-0002-6986-6756" }, { "family_name": "Costa", "given_name": "Enrico", "orcid": "0000-0003-4925-8523" }, { "family_name": "Silvestri", "given_name": "Stefano", "orcid": "0000-0002-8665-0105" }, { "family_name": "Zhou", "given_name": "Ping", "orcid": "0000-0002-5683-822X" }, { "family_name": "Bucciantini", "given_name": "Niccol\u00f2", "orcid": "0000-0002-8848-1392" }, { "family_name": "Di Marco", "given_name": "Alessandro", "orcid": "0000-0003-0331-3259" }, { "family_name": "Weisskopf", "given_name": "Martin C.", "orcid": "0000-0002-5270-4240" }, { "family_name": "Baldini", "given_name": "Luca", "orcid": "0000-0002-9785-7726" }, { "family_name": "Doroshenko", "given_name": "Victor", "orcid": "0000-0001-8162-1105" }, { "family_name": "Ehlert", "given_name": "Steven R.", "orcid": "0000-0003-4420-2838" }, { "family_name": "Heyl", "given_name": "Jeremy", "orcid": "0000-0001-9739-367X" }, { "family_name": "Kaaret", "given_name": "Philip", "orcid": "0000-0002-3638-0637" }, { "family_name": "Kim", "given_name": "Dawoon E.", "orcid": "0000-0001-5717-3736" }, { "family_name": "Marin", "given_name": "Fr\u00e9d\u00e9ric", "orcid": "0000-0003-4952-0835" }, { "family_name": "Mizuno", "given_name": "Tsunefumi", "orcid": "0000-0001-7263-0296" }, { "family_name": "Ng", "given_name": "Chi-Yung", "orcid": "0000-0002-5847-2612" }, { "family_name": "Pesce-Rollins", "given_name": "Melissa", "orcid": "0000-0003-1790-8018" }, { "family_name": "Sgr\u00f2", "given_name": "Carmelo", "orcid": "0000-0001-5676-6214" }, { "family_name": "Soffitta", "given_name": "Paolo", "orcid": "0000-0002-7781-4104" }, { "family_name": "Swartz", "given_name": "Douglas A.", "orcid": "0000-0002-2954-4461" }, { "family_name": "Tamagawa", "given_name": "Toru", "orcid": "0000-0002-8801-6263" }, { "family_name": "Xie", "given_name": "Fei", "orcid": "0000-0002-0105-5826" }, { "family_name": "Agudo", "given_name": "Iv\u00e1n", "orcid": "0000-0002-3777-6182" }, { "family_name": "Antonelli", "given_name": "Lucio A.", "orcid": "0000-0002-5037-9034" }, { "family_name": "Bachetti", "given_name": "Matteo", "orcid": "0000-0002-4576-9337" }, { "family_name": "Baumgartner", "given_name": "Wayne H.", "orcid": "0000-0002-5106-0463" }, { "family_name": "Bellazzini", "given_name": "Ronaldo", "orcid": "0000-0002-2469-7063" }, { "family_name": "Bianchi", "given_name": "Stefano", "orcid": "0000-0002-4622-4240" }, { "family_name": "Bongiorno", "given_name": "Stephen D.", "orcid": "0000-0002-0901-2097" }, { "family_name": "Bonino", "given_name": "Raffaella", "orcid": "0000-0002-4264-1215" }, { "family_name": "Brez", "given_name": "Alessandro", "orcid": "0000-0002-9460-1821" }, { "family_name": "Capitanio", "given_name": "Fiamma", "orcid": "0000-0002-6384-3027" }, { "family_name": "Castellano", "given_name": "Simone", "orcid": "0000-0003-1111-4292" }, { "family_name": "Cavazzuti", "given_name": "Elisabetta", "orcid": "0000-0001-7150-9638" }, { "family_name": "Chen", "given_name": "Chien-Ting", "orcid": "0000-0002-4945-5079" }, { "family_name": "Ciprini", "given_name": "Stefano", "orcid": "0000-0002-0712-2479" }, { "family_name": "De Rosa", "given_name": "Alessandra", "orcid": "0000-0001-5668-6863" }, { "family_name": "Del Monte", "given_name": "Ettore", "orcid": "0000-0002-3013-6334" }, { "family_name": "Di Gesu", "given_name": "Laura", "orcid": "0000-0002-5614-5028" }, { "family_name": "Di Lalla", "given_name": "Niccol\u00f2", "orcid": "0000-0002-7574-1298" }, { "family_name": "Donnarumma", "given_name": "Immacolata", "orcid": "0000-0002-4700-4549" }, { "family_name": "Dov\u010diak", "given_name": "Michal", "orcid": "0000-0003-0079-1239" }, { "family_name": "Enoto", "given_name": "Teruaki", "orcid": "0000-0003-1244-3100" }, { "family_name": "Evangelista", "given_name": "Yuri", "orcid": "0000-0001-6096-6710" }, { "family_name": "Fabiani", "given_name": "Sergio", "orcid": "0000-0003-1533-0283" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Gunji", "given_name": "Shuichi", "orcid": "0000-0002-5881-2445" }, { "family_name": "Iwakiri", "given_name": "Wataru", "orcid": "0000-0002-0207-9010" }, { "family_name": "Jorstad", "given_name": "Svetlana G.", "orcid": "0000-0001-9522-5453" }, { "family_name": "Karas", "given_name": "Vladimir", "orcid": "0000-0002-5760-0459" }, { "family_name": "Kislat", "given_name": "Fabian", "orcid": "0000-0001-7477-0380" }, { "family_name": "Kitaguchi", "given_name": "Takao" }, { "family_name": "Kolodziejczak", "given_name": "Jeffery J.", "orcid": "0000-0002-0110-6136" }, { "family_name": "Krawczynski", "given_name": "Henric", "orcid": "0000-0002-1084-6507" }, { "family_name": "La Monaca", "given_name": "Fabio", "orcid": "0000-0001-8916-4156" }, { "family_name": "Latronico", "given_name": "Luca", "orcid": "0000-0002-0984-1856" }, { "family_name": "Liodakis", "given_name": "Ioannis", "orcid": "0000-0001-9200-4006" }, { "family_name": "Maldera", "given_name": "Simone", "orcid": "0000-0002-0698-4421" }, { "family_name": "Manfreda", "given_name": "Alberto", "orcid": "0000-0002-0998-4953" }, { "family_name": "Marinucci", "given_name": "Andrea", "orcid": "0000-0002-2055-4946" }, { "family_name": "Marscher", "given_name": "Alan P.", "orcid": "0000-0001-7396-3332" }, { "family_name": "Marshall", "given_name": "Herman L.", "orcid": "0000-0002-6492-1293" }, { "family_name": "Massaro", "given_name": "Francesco", "orcid": "0000-0002-1704-9850" }, { "family_name": "Matt", "given_name": "Giorgio", "orcid": "0000-0002-2152-0916" }, { "family_name": "Mitsuishi", "given_name": "Ikuyuki", "orcid": "0000-0002-9901-233X" }, { "family_name": "Muleri", "given_name": "Fabio", "orcid": "0000-0003-3331-3794" }, { "family_name": "Negro", "given_name": "Michela", "orcid": "0000-0002-6548-5622" }, { "family_name": "O'Dell", "given_name": "Stephen L.", "orcid": "0000-0002-1868-8056" }, { "family_name": "Omodei", "given_name": "Nicola", "orcid": "0000-0002-5448-7577" }, { "family_name": "Oppedisano", "given_name": "Chiara", "orcid": "0000-0001-6194-4601" }, { "family_name": "Papitto", "given_name": "Alessandro", "orcid": "0000-0001-6289-7413" }, { "family_name": "Pavlov", "given_name": "George G.", "orcid": "0000-0002-7481-5259" }, { "family_name": "Peirson", "given_name": "Abel L.", "orcid": "0000-0001-6292-1911" }, { "family_name": "Perri", "given_name": "Matteo", "orcid": "0000-0003-3613-4409" }, { "family_name": "Petrucci", "given_name": "Pierre-Olivier", "orcid": "0000-0001-6061-3480" }, { "family_name": "Pilia", "given_name": "Maura", "orcid": "0000-0001-7397-8091" }, { "family_name": "Possenti", "given_name": "Andrea", "orcid": "0000-0001-5902-3731" }, { "family_name": "Poutanen", "given_name": "Juri", "orcid": "0000-0002-0983-0049" }, { "family_name": "Puccetti", "given_name": "Simonetta", "orcid": "0000-0002-2734-7835" }, { "family_name": "Ramsey", "given_name": "Brian D.", "orcid": "0000-0003-1548-1524" }, { "family_name": "Rankin", "given_name": "John", "orcid": "0000-0002-9774-0560" }, { "family_name": "Ratheesh", "given_name": "Ajay", "orcid": "0000-0003-0411-4243" }, { "family_name": "Roberts", "given_name": "Oliver J.", "orcid": "0000-0002-7150-9061" }, { "family_name": "Romani", "given_name": "Roger W.", "orcid": "0000-0001-6711-3286" }, { "family_name": "Spandre", "given_name": "Gloria", "orcid": "0000-0003-0802-3453" }, { "family_name": "Tavecchio", "given_name": "Fabrizio", "orcid": "0000-0003-0256-0995" }, { "family_name": "Taverna", "given_name": "Roberto", "orcid": "0000-0002-1768-618X" }, { "family_name": "Tawara", "given_name": "Yuzuru" }, { "family_name": "Tennant", "given_name": "Allyn F.", "orcid": "0000-0002-9443-6774" }, { "family_name": "Thomas", "given_name": "Nicholas E.", "orcid": "0000-0003-0411-4606" }, { "family_name": "Tombesi", "given_name": "Francesco", "orcid": "0000-0002-6562-8654" }, { "family_name": "Trois", "given_name": "Alessio", "orcid": "0000-0002-3180-6002" }, { "family_name": "Tsygankov", "given_name": "Sergey S.", "orcid": "0000-0002-9679-0793" }, { "family_name": "Turolla", "given_name": "Roberto", "orcid": "0000-0003-3977-8760" }, { "family_name": "Wu", "given_name": "Kinwah", "orcid": "0000-0002-7568-8765" }, { "family_name": "Zane", "given_name": "Silvia", "orcid": "0000-0001-5326-880X" } ], "abstract": "Synchrotron X-ray emission has been detected from nearly a dozen young supernova remnants (SNRs). X-rays of synchrotron origin exhibit linear polarization in a regular, non-randomly oriented magnetic field. The significant polarized X-ray emission from four such SNRs has already been reported on the basis of observations with the Imaging X-ray Polarimetry Explorer (IXPE). The magnetic-field structure as derived from IXPE observations is radial for Cassiopeia A, Tycho's SNR, and SN 1006, and tangential for RX J1713.7\u22123946. The latter together with the recent detection of a tangential magnetic field in SNR 1E 0102.2-7219 by the Australia Telescope Compact Array in the radio band shows that tangential magnetic fields can also be present in young SNRs. Thus, the dichotomy in polarization between young and middle-aged SNRs (radial magnetic fields in young SNRs, but tangential magnetic fields in middle-aged SNRs), previously noticed in the radio band, deserves additional attention. The present analysis of IXPE observations determines, for the first time, a magnetic-field structure in the northwestern rim of Vela Jr, also known as RX J0852.0\u22124622, and provides a new example of a young SNR with a tangential magnetic field.", "doi": "10.1051/0004-6361/202452062", "issn": "0004-6361", "publisher": "EDP Sciences", "publication": "Astronomy and Astrophysics", "publication_date": "2024-12", "volume": "692", "pages": "A59" }, { "id": "authors:fjhpg-5j723", "collection": "authors", "collection_id": "fjhpg-5j723", "cite_using_url": "https://authors.library.caltech.edu/records/fjhpg-5j723", "type": "article", "title": "The high energy X-ray probe (HEX-P): science overview", "author": [ { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Stern", "given_name": "Daniel", "orcid": "0000-0003-2686-9241", "clpid": "Stern-D" }, { "family_name": "Madsen", "given_name": "Kristin", "orcid": "0000-0003-1252-4891" }, { "family_name": "Smith", "given_name": "Miles", "clpid": "Smith-Miles" }, { "family_name": "Grefenstette", "given_name": "Brian", "orcid": "0000-0002-1984-2932", "clpid": "Grefenstette-Brian" }, { "family_name": "Ajello", "given_name": "Marco", "orcid": "0000-0002-6584-1703" }, { "family_name": "Alford", "given_name": "Jason" }, { "family_name": "Annuar", "given_name": "Adlyka", "orcid": "0000-0003-0387-1429" }, { "family_name": "Bachetti", "given_name": "Matteo", "orcid": "0000-0002-4576-9337" }, { "family_name": "Balokovi\u0107", "given_name": "Mislav", "orcid": "0000-0003-0476-6647" }, { "family_name": "Beckmann", "given_name": "Ricarda S." }, { "family_name": "Bianchi", "given_name": "Stefano", "orcid": "0000-0002-4622-4240" }, { "family_name": "Biccari", "given_name": "Daniela", "clpid": "Biccari-Daniela" }, { "family_name": "Boorman", "given_name": "Peter", "orcid": "0000-0001-9379-4716", "clpid": "Boorman-Peter" }, { "family_name": "Brightman", "given_name": "Murray", "orcid": "0000-0002-8147-2602", "clpid": "Brightman-Murray" }, { "family_name": "Buchner", "given_name": "Johannes", "orcid": "0000-0003-0426-6634" }, { "family_name": "Bulbul", "given_name": "Esra" }, { "family_name": "Chen", "given_name": "Chien-Ting", "orcid": "0000-0002-4945-5079" }, { "family_name": "Civano", "given_name": "Francesca", "orcid": "0000-0002-2115-1137" }, { "family_name": "Coley", "given_name": "Joel", "orcid": "0000-0001-7532-8359" }, { "family_name": "Connors", "given_name": "Riley M. T.", "orcid": "0000-0002-8908-759X" }, { "family_name": "Del Santo", "given_name": "Melania" }, { "family_name": "Gesu", "given_name": "Laura Di", "orcid": "0000-0002-5614-5028" }, { "family_name": "Draghis", "given_name": "Paul A." }, { "family_name": "Fragile", "given_name": "P. Chris" }, { "family_name": "G\u00farpide", "given_name": "Andr\u00e9s" }, { "family_name": "Gangi", "given_name": "Manuele", "orcid": "0000-0002-8364-7795" }, { "family_name": "Gezari", "given_name": "Suvi", "orcid": "0000-0003-3703-5154" }, { "family_name": "Harrison", "given_name": "Fiona A.", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" }, { "family_name": "Kammoun", "given_name": "Elias", "orcid": "0000-0002-0273-218X" }, { "family_name": "Lanzuisi", "given_name": "Giorgio", "orcid": "0000-0001-9094-0984" }, { "family_name": "Lehmer", "given_name": "Bret", "orcid": "0000-0003-2192-3296" }, { "family_name": "Lohfink", "given_name": "Anne" }, { "family_name": "Ludlam", "given_name": "Renee", "orcid": "0000-0002-8961-939X" }, { "family_name": "Marchesi", "given_name": "Stefano", "orcid": "0000-0001-5544-0749" }, { "family_name": "Marcotulli", "given_name": "Lea" }, { "family_name": "Margutti", "given_name": "Raffaella", "orcid": "0000-0003-4768-7586" }, { "family_name": "Masterson", "given_name": "Megan", "orcid": "0000-0003-4127-0739" }, { "family_name": "Merloni", "given_name": "Andrea" }, { "family_name": "Middleton", "given_name": "Matthew", "orcid": "0000-0002-8183-2970" }, { "family_name": "Mori", "given_name": "Kaya", "orcid": "0000-0002-9709-5389" }, { "family_name": "Moretti", "given_name": "Alberto" }, { "family_name": "Nandra", "given_name": "Kirpal", "orcid": "0000-0002-7150-9192" }, { "family_name": "Perez", "given_name": "Kerstin", "orcid": "0000-0002-6404-4737" }, { "family_name": "Pfeifle", "given_name": "Ryan W.", "orcid": "0000-0001-8640-8522" }, { "family_name": "Pinto", "given_name": "Ciro", "orcid": "0000-0003-2532-7379" }, { "family_name": "Piotrowska", "given_name": "Joanna", "clpid": "Piotrowska-Joanna" }, { "family_name": "Ponti", "given_name": "Gabriele" }, { "family_name": "Pottschmidt", "given_name": "Katja" }, { "family_name": "Predehl", "given_name": "Peter" }, { "family_name": "Puccetti", "given_name": "Simonetta", "orcid": "0000-0002-2734-7835" }, { "family_name": "Rau", "given_name": "Arne", "orcid": "0000-0001-5990-6243" }, { "family_name": "Reynolds", "given_name": "Stephen" }, { "family_name": "Santangelo", "given_name": "Andrea", "orcid": "0000-0003-4187-9560" }, { "family_name": "Spiga", "given_name": "Daniele", "orcid": "0000-0002-2991-6384" }, { "family_name": "Tomsick", "given_name": "John A.", "orcid": "0000-0001-5506-9855" }, { "family_name": "Torres-Alb\u00e0", "given_name": "N\u00faria" }, { "family_name": "Walton", "given_name": "Dominic J.", "orcid": "0000-0001-5819-3552" }, { "family_name": "Wilkins", "given_name": "Daniel" }, { "family_name": "Wilms", "given_name": "Joern", "orcid": "0000-0003-2065-5410" }, { "family_name": "Zhang", "given_name": "Will", "orcid": "0000-0002-1426-9698" }, { "family_name": "Zhao", "given_name": "Xiurui" }, { "literal": "HEX-P Collaboration" } ], "editor": [ { "family_name": "Fornengo", "given_name": "Nicolao", "orcid": "0000-0002-3074-3118" } ], "contributor": [ { "family_name": "Di Mauro", "given_name": "Mattia", "orcid": "0000-0003-2759-5625" }, { "family_name": "Martin-Carrillo", "given_name": "Antonio", "orcid": "0000-0001-5108-0627" } ], "abstract": "To answer NASA's call for a sensitive X-ray observatory in the 2030s, we present the High Energy X-ray Probe (HEX-P) mission concept. HEX-P is designed to provide the required capabilities to explore current scientific questions and make new discoveries with a broadband X-ray observatory that simultaneously measures sources from 0.2 to 80 keV. HEX-P's main scientific goals include: 1) understand the growth of supermassive black holes and how they drive galaxy evolution; 2) explore the lower mass populations of white dwarfs, neutron stars, and stellar-mass black holes in the nearby universe; 3) explain the physics of the mysterious corona, the luminous plasma close to the central engine of accreting compact objects that dominates cosmic X-ray emission; and 4) find the sources of the highest energy particles in the Galaxy. These goals motivate a sensitive, broadband X-ray observatory with imaging, spectroscopic, and timing capabilities, ensuring a versatile platform to serve a broad General Observer (GO) and Guest Investigator (GI) community. In this paper, we present an overview of these mission goals, which have been extensively discussed in a collection of more than a dozen papers that are part of this Research Topic volume. The proposed investigations will address key questions in all three science themes highlighted by Astro2020, including their associated priority areas. HEX-P will extend the capabilities of the most sensitive low- and high-energy X-ray satellites currently in orbit and will complement existing and planned high-energy, time-domain, and multi-messenger facilities in the next decade.", "doi": "10.3389/fspas.2024.1471585", "issn": "2296-987X", "publisher": "Frontiers Media SA", "publication": "Frontiers in Astronomy and Space Sciences", "publication_date": "2024-11-25", "volume": "11", "pages": "1471585" }, { "id": "authors:xagym-va411", "collection": "authors", "collection_id": "xagym-va411", "cite_using_url": "https://authors.library.caltech.edu/records/xagym-va411", "type": "article", "title": "Subrelativistic Outflow and Hours-timescale Large-amplitude X-Ray Dips during Super-Eddington Accretion onto a Low-mass Massive Black Hole in the Tidal Disruption Event AT2022lri", "author": [ { "family_name": "Yao", "given_name": "Yuhan", "orcid": "0000-0001-6747-8509" }, { "family_name": "Guolo", "given_name": "Muryel", "orcid": "0000-0002-5063-0751" }, { "family_name": "Tombesi", "given_name": "Francesco", "orcid": "0000-0002-6562-8654" }, { "family_name": "Li", "given_name": "Ruancun", "orcid": "0000-0001-8496-4162" }, { "family_name": "Gezari", "given_name": "Suvi", "orcid": "0000-0003-3703-5154" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Dai", "given_name": "Lixin", "orcid": "0000-0002-9589-5235" }, { "family_name": "Chornock", "given_name": "Ryan", "orcid": "0000-0002-7706-5668" }, { "family_name": "Lu", "given_name": "Wenbin", "orcid": "0000-0002-1568-7461" }, { "family_name": "Kulkarni", "given_name": "S. R.", "orcid": "0000-0001-5390-8563", "clpid": "Kulkarni-S-R" }, { "family_name": "Gendreau", "given_name": "Keith C.", "orcid": "0000-0001-7115-2819" }, { "family_name": "Pasham", "given_name": "Dheeraj R.", "orcid": "0000-0003-1386-7861" }, { "family_name": "Cenko", "given_name": "S. Bradley", "orcid": "0000-0003-1673-970X" }, { "family_name": "Kara", "given_name": "Erin", "orcid": "0000-0003-0172-0854" }, { "family_name": "Margutti", "given_name": "Raffaella", "orcid": "0000-0003-4768-7586" }, { "family_name": "Ajay", "given_name": "Yukta", "orcid": "0009-0007-8764-9062" }, { "family_name": "Wevers", "given_name": "Thomas", "orcid": "0000-0002-4043-9400" }, { "family_name": "Kwan", "given_name": "Tom M.", "orcid": "0000-0003-0509-2541" }, { "family_name": "Andreoni", "given_name": "Igor", "orcid": "0000-0002-8977-1498" }, { "family_name": "Bloom", "given_name": "Joshua S.", "orcid": "0000-0002-7777-216X" }, { "family_name": "Drake", "given_name": "Andrew J.", "orcid": "0000-0003-0228-6594", "clpid": "Drake-Andrew-J" }, { "family_name": "Graham", "given_name": "Matthew J.", "orcid": "0000-0002-3168-0139", "clpid": "Graham-M-J" }, { "family_name": "Hammerstein", "given_name": "Erica", "orcid": "0000-0002-5698-8703" }, { "family_name": "Laher", "given_name": "Russ R.", "orcid": "0000-0003-2451-5482", "clpid": "Laher-R-R" }, { "family_name": "LeBaron", "given_name": "Natalie", "orcid": "0000-0002-2249-0595" }, { "family_name": "Mahabal", "given_name": "Ashish A.", "orcid": "0000-0003-2242-0244", "clpid": "Mahabal-A-A" }, { "family_name": "O'Connor", "given_name": "Brendan", "orcid": "0000-0002-9700-0036" }, { "family_name": "Purdum", "given_name": "Josiah", "orcid": "0000-0003-1227-3738", "clpid": "Purdum-Josiah" }, { "family_name": "Ravi", "given_name": "Vikram", "orcid": "0000-0002-7252-5485", "clpid": "Ravi-Vikram" }, { "family_name": "Sears", "given_name": "Huei", "orcid": "0000-0001-8023-4912" }, { "family_name": "Sharma", "given_name": "Yashvi", "orcid": "0000-0003-4531-1745", "clpid": "Sharma-Yashvi" }, { "family_name": "Smith", "given_name": "Roger", "orcid": "0000-0001-7062-9726", "clpid": "Smith-R-M" }, { "family_name": "Sollerman", "given_name": "Jesper", "orcid": "0000-0003-1546-6615" }, { "family_name": "Somalwar", "given_name": "Jean J.", "orcid": "0000-0001-8426-5732", "clpid": "Somalwar-Jean-J" }, { "family_name": "Wold", "given_name": "Avery", "orcid": "0000-0002-9998-6732", "clpid": "Wold-Avery" } ], "abstract": "
\n

We present the tidal disruption event (TDE) AT2022lri, hosted in a nearby (≈144 Mpc) quiescent galaxy with a low-mass massive black hole (104M\u2299 < MBH < 106M\u2299). AT2022lri belongs to the TDE-H+He subtype. More than 1 Ms of X-ray data were collected with NICER, Swift, and XMM-Newton from 187 to 672 days after peak. The X-ray luminosity gradually declined from 1.5 × 1044 erg s−1 to 1.5 × 1043 erg s−1 and remains much above the UV and optical luminosity, consistent with a super-Eddington accretion flow viewed face-on. Sporadic strong X-ray dips atop a long-term decline are observed, with a variability timescale of ≈0.5 hr–1 days and amplitude of ≈2–8. When fitted with simple continuum models, the X-ray spectrum is dominated by a thermal disk component with inner temperature going from ∼146 to ∼86 eV. However, there are residual features that peak around 1 keV, which, in some cases, cannot be reproduced by a single broad emission line. We analyzed a subset of time-resolved spectra with two physically motivated models describing a scenario either where ionized absorbers contribute extra absorption and emission lines or where disk reflection plays an important role. Both models provide good and statistically comparable fits, show that the X-ray dips are correlated with drops in the inner disk temperature, and require the existence of subrelativistic (0.1–0.3c) ionized outflows. We propose that the disk temperature fluctuation stems from episodic drops of the mass accretion rate triggered by magnetic instabilities or/and wobbling of the inner accretion disk along the black hole's spin axis.

\n
", "doi": "10.3847/1538-4357/ad7d93", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2024-11-20", "series_number": "1", "volume": "976", "issue": "1", "pages": "34" }, { "id": "authors:vjj0z-5v497", "collection": "authors", "collection_id": "vjj0z-5v497", "cite_using_url": "https://authors.library.caltech.edu/records/vjj0z-5v497", "type": "article", "title": "A View of the Long-term Spectral Behavior of Ultracompact X-Ray Binary 4U 0614+091", "author": [ { "family_name": "Moutard", "given_name": "D. L.", "orcid": "0000-0003-1463-8702" }, { "family_name": "Ludlam", "given_name": "R. M.", "orcid": "0000-0002-8961-939X" }, { "family_name": "Cackett", "given_name": "E. M.", "orcid": "0000-0002-8294-9281" }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Miller", "given_name": "J. M.", "orcid": "0000-0003-2869-7682" }, { "family_name": "Wilkins", "given_name": "D. R.", "orcid": "0000-0002-4794-5998" } ], "abstract": "

In this study, we examine 51 archival NICER observations and six archival NuSTAR observations of the neutron star ultracompact X-ray binary (UCXB) 4U 0614+091, which span over 5 yr. The source displays persistent reflection features, so we use a reflection model designed for UCXBs, with overabundant carbon and oxygen (xillverCO) to study how various components of the system vary over time. The flux of this source is known to vary quasiperiodically on a timescale of a few days, so we study how the various model components change as the overall flux varies. The flux of most components scales linearly with the overall flux, while the power law, representing coronal emission, is anticorrelated, as expected. This is consistent with previous studies of the source. We also find that during observations of the high-soft state, the disk emissivity profile as a function of radius becomes steeper. We interpret this as the corona receding to be closer to the compact object during these states, at which point the assumed power law illumination of xillverCO may be inadequate to describe the illumination of the disk.

", "doi": "10.3847/1538-4357/ad794d", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2024-11-01", "series_number": "1", "volume": "975", "issue": "1", "pages": "68" }, { "id": "authors:7skrd-ajz35", "collection": "authors", "collection_id": "7skrd-ajz35", "cite_using_url": "https://authors.library.caltech.edu/records/7skrd-ajz35", "type": "article", "title": "Observations of Low and Intermediate Spectral Peak Blazars with the Imaging X-Ray Polarimetry Explorer", "author": [ { "family_name": "Marshall", "given_name": "Herman L.", "orcid": "0000-0002-6492-1293" }, { "family_name": "Liodakis", "given_name": "Ioannis", "orcid": "0000-0001-9200-4006" }, { "family_name": "Marscher", "given_name": "Alan P.", "orcid": "0000-0001-7396-3332" }, { "family_name": "Di Lalla", "given_name": "Niccol\u00f2", "orcid": "0000-0002-7574-1298" }, { "family_name": "Jorstad", "given_name": "Svetlana G.", "orcid": "0000-0001-6158-1708" }, { "family_name": "Kim", "given_name": "Dawoon E.", "orcid": "0000-0001-5717-3736" }, { "family_name": "Middei", "given_name": "Riccardo", "orcid": "0000-0001-9815-9092" }, { "family_name": "Negro", "given_name": "Michela", "orcid": "0000-0002-6548-5622" }, { "family_name": "Omodei", "given_name": "Nicola", "orcid": "0000-0002-5448-7577" }, { "family_name": "Peirson", "given_name": "Abel L.", "orcid": "0000-0001-6292-1911" }, { "family_name": "Perri", "given_name": "Matteo", "orcid": "0000-0003-3613-4409" }, { "family_name": "Puccetti", "given_name": "Simonetta", "orcid": "0000-0002-2734-7835" }, { "family_name": "Laurenti", "given_name": "Marco", "orcid": "0000-0001-5762-6360" }, { "family_name": "Agudo", "given_name": "Iv\u00e1n", "orcid": "0000-0002-3777-6182" }, { "family_name": "Bonnoli", "given_name": "Giacomo", "orcid": "0000-0003-2464-9077" }, { "family_name": "Berdyugin", "given_name": "Andrei V.", "orcid": "0000-0002-9353-5164" }, { "family_name": "Cavazzuti", "given_name": "Elisabetta", "orcid": "0000-0001-7150-9638" }, { "family_name": "Rodriguez Cavero", "given_name": "Nicole", "orcid": "0000-0001-5256-0278" }, { "family_name": "Donnarumma", "given_name": "Immacolata", "orcid": "0000-0002-4700-4549" }, { "family_name": "Di Gesu", "given_name": "Laura", "orcid": "0000-0002-5614-5028" }, { "family_name": "Jormanainen", "given_name": "Jenni", "orcid": "0000-0003-4519-7751" }, { "family_name": "Krawczynski", "given_name": "Henric", "orcid": "0000-0002-1084-6507" }, { "family_name": "Lindfors", "given_name": "Elina", "orcid": "0000-0002-9155-6199" }, { "family_name": "Madjeski", "given_name": "Greg" }, { "family_name": "Marin", "given_name": "Fr\u00e9d\u00e9ric", "orcid": "0000-0003-4952-0835" }, { "family_name": "Massaro", "given_name": "Francesco", "orcid": "0000-0002-1704-9850" }, { "family_name": "Pacciani", "given_name": "Luigi", "orcid": "0000-0001-6897-5996" }, { "family_name": "Poutanen", "given_name": "Juri", "orcid": "0000-0002-0983-0049" }, { "family_name": "Tavecchio", "given_name": "Fabrizio", "orcid": "0000-0003-0256-0995" }, { "family_name": "Kouch", "given_name": "Pouya M.", "orcid": "0000-0002-9328-2750" }, { "family_name": "Aceituno", "given_name": "Francisco Jos\u00e9", "orcid": "0000-0001-8074-4760" }, { "family_name": "Bernardos", "given_name": "Maria I.", "orcid": "0000-0001-8872-1168" }, { "family_name": "Casanova", "given_name": "V\u00edctor", "orcid": "0000-0003-2036-8999" }, { "family_name": "Garc\u00eda-Comas", "given_name": "Maya", "orcid": "0000-0003-2323-4486" }, { "family_name": "Ag\u00eds-Gonz\u00e1lez", "given_name": "Beatriz", "orcid": "0000-0001-7702-8931" }, { "family_name": "Husillos", "given_name": "C\u00e9sar", "orcid": "0000-0001-8286-5443" }, { "family_name": "Marchini", "given_name": "Alessandro", "orcid": "0000-0003-3779-6762" }, { "family_name": "Sota", "given_name": "Alfredo", "orcid": "0000-0002-9404-6952" }, { "family_name": "Blinov", "given_name": "Dmitry", "orcid": "0000-0003-0611-5784" }, { "family_name": "Bourbah", "given_name": "Ioakeim G.", "orcid": "0000-0002-8597-6154" }, { "family_name": "Kielhmann", "given_name": "Sebastian" }, { "family_name": "Kontopodis", "given_name": "Evangelos", "orcid": "0009-0009-8043-0986" }, { "family_name": "Mandarakas", "given_name": "Nikos", "orcid": "0000-0002-2567-2132" }, { "family_name": "Romanopoulos", "given_name": "Stylianos", "orcid": "0000-0002-2897-2448" }, { "family_name": "Skalidis", "given_name": "Raphael", "orcid": "0000-0003-2337-0277", "clpid": "Skalidis-Rafail" }, { "family_name": "Vervelaki", "given_name": "Anna", "orcid": "0000-0003-0271-9724" }, { "family_name": "Borman", "given_name": "George A.", "orcid": "0000-0002-7262-6710" }, { "family_name": "Kopatskaya", "given_name": "Evgenia N.", "orcid": "0000-0001-9518-337X" }, { "family_name": "Larionova", "given_name": "Elena G.", "orcid": "0000-0002-2471-6500" }, { "family_name": "Morozova", "given_name": "Daria A.", "orcid": "0000-0002-9407-7804" }, { "family_name": "Savchenko", "given_name": "Sergey S.", "orcid": "0000-0003-4147-3851" }, { "family_name": "Vasilyev", "given_name": "Andrey A.", "orcid": "0000-0002-8293-0214" }, { "family_name": "Zhovtan", "given_name": "Alexey V." }, { "family_name": "Casadio", "given_name": "Carolina", "orcid": "0000-0003-1117-2863" }, { "family_name": "Escudero", "given_name": "Juan", "orcid": "0000-0002-4131-655X" }, { "family_name": "Kramer", "given_name": "Joana", "orcid": "0009-0003-3011-0454" }, { "family_name": "Myserlis", "given_name": "Ioannis", "orcid": "0000-0003-3025-9497" }, { "family_name": "Trainou", "given_name": "Efthalia" }, { "family_name": "Imazawa", "given_name": "Ryo", "orcid": "0000-0002-0643-7946" }, { "family_name": "Sasada", "given_name": "Mahito", "orcid": "0000-0001-5946-9960" }, { "family_name": "Fukazawa", "given_name": "Yasushi", "orcid": "0000-0002-0921-8837" }, { "family_name": "Kawabata", "given_name": "Koji S.", "orcid": 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"family_name": "Kameno", "given_name": "Seiji", "orcid": "0000-0002-5158-0063" }, { "family_name": "Kneissl", "given_name": "Ruediger", "orcid": "0000-0002-5580-006X" }, { "family_name": "Messias", "given_name": "Hugo", "orcid": "0000-0002-2985-7994" }, { "family_name": "Nagai", "given_name": "Hiroshi", "orcid": "0000-0003-0292-3645" }, { "family_name": "Antonelli", "given_name": "Lucio A.", "orcid": "0000-0002-5037-9034" }, { "family_name": "Bachetti", "given_name": "Matteo", "orcid": "0000-0002-4576-9337" }, { "family_name": "Baldini", "given_name": "Luca", "orcid": "0000-0002-9785-7726" }, { "family_name": "Baumgartner", "given_name": "Wayne H.", "orcid": "0000-0002-5106-0463" }, { "family_name": "Bellazzini", "given_name": "Ronaldo", "orcid": "0000-0002-2469-7063" }, { "family_name": "Bianchi", "given_name": "Stefano", "orcid": "0000-0002-4622-4240" }, { "family_name": "Bongiorno", "given_name": "Stephen D.", "orcid": "0000-0002-0901-2097" }, { "family_name": "Bonino", "given_name": "Raffaella", "orcid": "0000-0002-4264-1215" }, { "family_name": "Brez", "given_name": "Alessandro", "orcid": "0000-0002-9460-1821" }, { "family_name": "Bucciantini", "given_name": "Niccol\u00f2", "orcid": "0000-0002-8848-1392" }, { "family_name": "Capitanio", "given_name": "Fiamma", "orcid": "0000-0002-6384-3027" }, { "family_name": "Castellano", "given_name": "Simone", "orcid": "0000-0003-1111-4292" }, { "family_name": "Chen", "given_name": "Chen-Ting", "orcid": "0000-0002-4945-5079" }, { "family_name": "Ciprini", "given_name": "Stefano", "orcid": "0000-0002-0712-2479" }, { "family_name": "Costa", "given_name": "Enrico", "orcid": "0000-0003-4925-8523" }, { "family_name": "De Rosa", "given_name": "Alessandra", "orcid": "0000-0001-5668-6863" }, { "family_name": "Del Monte", "given_name": "Ettore", "orcid": "0000-0002-3013-6334" }, { "family_name": "Di Marco", "given_name": "Alessandro", "orcid": "0000-0003-0331-3259" }, { "family_name": "Doroshenko", "given_name": "Victor", "orcid": "0000-0001-8162-1105" }, { "family_name": "Dov\u010diak", "given_name": "Michal", "orcid": "0000-0003-0079-1239" }, { "family_name": "Ehlert", "given_name": "Steven R.", "orcid": "0000-0003-4420-2838" }, { "family_name": "Enoto", "given_name": "Teruaki", "orcid": "0000-0003-1244-3100" }, { "family_name": "Evangelista", "given_name": "Yuri", "orcid": "0000-0001-6096-6710" }, { "family_name": "Fabiani", "given_name": "Sergio", "orcid": "0000-0003-1533-0283" }, { "family_name": "Ferrazzoli", "given_name": "Riccardo", "orcid": "0000-0003-1074-8605" }, { "family_name": "Garcia", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Gunji", "given_name": "Shuichi", "orcid": "0000-0002-5881-2445" }, { "family_name": "Hayashida", "given_name": "Kiyoshi" }, { "family_name": "Heyl", "given_name": "Jeremy", "orcid": "0000-0001-9739-367X" }, { "family_name": "Iwakiri", "given_name": "Wataru", "orcid": "0000-0002-0207-9010" }, { "family_name": "Kaaret", "given_name": "Philip", "orcid": "0000-0002-3638-0637" }, { "family_name": "Karas", "given_name": "Vladimir", "orcid": "0000-0002-5760-0459" }, { "family_name": "Kislat", "given_name": "Fabian", "orcid": "0000-0001-7477-0380" }, { "family_name": "Kitaguchi", "given_name": "Takao" }, { "family_name": "Kolodziejczak", "given_name": "Jeffery J.", "orcid": "0000-0002-0110-6136" }, { "family_name": "La Monaca", "given_name": "Fabio", "orcid": "0000-0001-8916-4156" }, { "family_name": "Latronico", "given_name": "Luca", "orcid": "0000-0002-0984-1856" }, { "family_name": "Maldera", "given_name": "Simone", "orcid": "0000-0002-0698-4421" }, { "family_name": "Manfreda", "given_name": "Alberto", "orcid": "0000-0002-0998-4953" }, { "family_name": "Marinucci", "given_name": "Andrea", "orcid": "0000-0002-2055-4946" }, { "family_name": "Matt", "given_name": "Giorgio", "orcid": "0000-0002-2152-0916" }, { "family_name": "Mitsuishi", "given_name": "Ikuyuki", "orcid": "0000-0002-9901-233X" }, { "family_name": "Muleri", "given_name": "Fabio", "orcid": "0000-0003-3331-3794" }, { "family_name": "Ng", "given_name": "C.-Y.", "orcid": "0000-0002-5847-2612" }, { "family_name": "O'Dell", "given_name": "Stephen L.", "orcid": "0000-0002-1868-8056" }, { "family_name": "Oppedisano", "given_name": "Chiara", "orcid": "0000-0001-6194-4601" }, { "family_name": "Papitto", "given_name": "Alessandro", "orcid": "0000-0001-6289-7413" }, { "family_name": "Pavlov", "given_name": "George G.", "orcid": "0000-0002-7481-5259" }, { "family_name": "Pesce-Rollins", "given_name": "Melissa", "orcid": "0000-0003-1790-8018" }, { "family_name": "Petrucci", "given_name": "Pierre-Olivier", "orcid": "0000-0001-6061-3480" }, { "family_name": "Pilia", "given_name": "Maura", "orcid": "0000-0001-7397-8091" }, { "family_name": "Possenti", "given_name": "Andrea", "orcid": "0000-0001-5902-3731" }, { "family_name": "Ramsey", "given_name": "Brian D.", "orcid": "0000-0003-1548-1524" }, { "family_name": "Rankin", "given_name": "John", "orcid": "0000-0002-9774-0560" }, { "family_name": "Ratheesh", "given_name": "Ajay", "orcid": "0000-0003-0411-4243" }, { "family_name": "Roberts", "given_name": "Oliver J.", "orcid": "0000-0002-7150-9061" }, { "family_name": "Romani", "given_name": "Roger W.", "orcid": "0000-0001-6711-3286" }, { "family_name": "Sgr\u00f2", "given_name": "Carmelo", "orcid": "0000-0001-5676-6214" }, { "family_name": "Slane", "given_name": "Patrick", "orcid": "0000-0002-6986-6756" }, { "family_name": "Spandre", "given_name": "Gloria", "orcid": "0000-0003-0802-3453" }, { "family_name": "Swartz", "given_name": "Douglas A.", "orcid": "0000-0002-2954-4461" }, { "family_name": "Tamagawa", "given_name": "Toru", "orcid": "0000-0002-8801-6263" }, { "family_name": "Taverna", "given_name": "Roberto", "orcid": "0000-0002-1768-618X" }, { "family_name": "Tawara", "given_name": "Yuzuru" }, { "family_name": "Tennant", "given_name": "Allyn F.", "orcid": "0000-0002-9443-6774" }, { "family_name": "Thomas", "given_name": "Nicholas E.", "orcid": "0000-0003-0411-4606" }, { "family_name": "Tombesi", "given_name": "Francesco", "orcid": "0000-0002-6562-8654" }, { "family_name": "Trois", "given_name": "Alessio", "orcid": "0000-0002-3180-6002" }, { "family_name": "Tsygankov", "given_name": "Sergey S.", "orcid": "0000-0002-9679-0793" }, { "family_name": "Turolla", "given_name": "Roberto", "orcid": "0000-0003-3977-8760" }, { "family_name": "Vink", "given_name": "Jacco", "orcid": "0000-0002-4708-4219" }, { "family_name": "Weisskopf", "given_name": "Martin C.", "orcid": "0000-0002-5270-4240" }, { "family_name": "Wu", "given_name": "Kinwah", "orcid": "0000-0002-7568-8765" }, { "family_name": "Xie", "given_name": "Fei", "orcid": "0000-0002-0105-5826" }, { "family_name": "Zane", "given_name": "Silvia", "orcid": "0000-0001-5326-880X" } ], "abstract": "

We present X-ray polarimetry observations from the Imaging X-ray Polarimetry Explorer (IXPE) of three low spectral peak and one intermediate spectral peak blazars, namely 3C 273, 3C 279, 3C 454.3, and S5 0716+714. For none of these objects was IXPE able to detect X-ray polarization at the 3σ level. However, we placed upper limits on the polarization degree at ∼10%–30%. The undetected polarizations favor models where the X-ray band is dominated by unpolarized photons upscattered by relativistic electrons in the jets of blazars, although hadronic models are not completely eliminated. We discuss the X-ray polarization upper limits in the context of our contemporaneous multiwavelength polarization campaigns.

", "doi": "10.3847/1538-4357/ad5671", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2024-09-01", "series_number": "1", "volume": "972", "issue": "1", "pages": "74" }, { "id": "authors:xyd1j-66r19", "collection": "authors", "collection_id": "xyd1j-66r19", "cite_using_url": "https://authors.library.caltech.edu/records/xyd1j-66r19", "type": "article", "title": "Cygnus X-3 revealed as a Galactic ultraluminous X-ray source by IXPE", "author": [ { "family_name": "Veledina", "given_name": "Alexandra", "orcid": "0000-0002-5767-7253", "clpid": "Veledina-Alexandra" }, { "family_name": "Muleri", "given_name": "Fabio", "orcid": "0000-0003-3331-3794" }, { "family_name": "Poutanen", "given_name": "Juri", "orcid": "0000-0002-0983-0049" }, { "family_name": "Podgorn\u00fd", "given_name": "Jakub", "orcid": "0000-0001-5418-291X" }, { "family_name": "Dov\u010diak", "given_name": "Michal", "orcid": "0000-0003-0079-1239" }, { "family_name": "Capitanio", "given_name": "Fiamma", "orcid": "0000-0002-6384-3027" }, { "family_name": "Churazov", "given_name": "Eugene", "orcid": "0000-0002-0322-884X" }, { "family_name": "De Rosa", "given_name": "Alessandra", "clpid": "/0000-0001-5668-6863" }, { "family_name": "Di Marco", "given_name": "Alessandro", "orcid": "0000-0003-0331-3259" }, { "family_name": "Forsblom", "given_name": "Sofia V.", "orcid": "0000-0001-9167-2790" }, { "family_name": "Kaaret", "given_name": "Philip", "orcid": "0000-0002-3638-0637" }, { "family_name": "Krawczynski", "given_name": "Henric", "orcid": "0000-0002-1084-6507" }, { "family_name": "La Monaca", "given_name": "Fabio", "orcid": "0000-0001-8916-4156" }, { "family_name": "Loktev", "given_name": "Vladislav", "orcid": "0000-0001-6894-871X" }, { "family_name": "Lutovinov", "given_name": "Alexander A.", "orcid": "0000-0002-6255-9972" }, { "family_name": "Molkov", "given_name": "Sergey V.", "orcid": "0000-0002-5983-5788" }, { "family_name": "Mushtukov", "given_name": "Alexander A.", "orcid": "0000-0003-2306-419X" }, { "family_name": "Ratheesh", "given_name": "Ajay", "orcid": "0000-0003-0411-4243" }, { "family_name": "Rodriguez Cavero", "given_name": "Nicole", "orcid": "0000-0001-5256-0278" }, { "family_name": "Steiner", "given_name": "James F.", "orcid": "0000-0002-5872-6061" }, { "family_name": "Sunyaev", "given_name": "Rashid A.", "orcid": "0000-0002-2764-7192" }, { "family_name": "Tsygankov", "given_name": "Sergey S.", "orcid": "0000-0002-9679-0793" }, { "family_name": "Weisskopf", "given_name": "Martin C.", "orcid": "0000-0002-5270-4240" }, { "family_name": "Zdziarski", "given_name": "Andrzej A.", "orcid": "0000-0002-0333-2452" }, { "family_name": "Bianchi", "given_name": "Stefano", "orcid": "0000-0002-4622-4240" }, { "family_name": "Bright", "given_name": "Joe S.", "orcid": "0000-0002-7735-5796" }, { "family_name": "Bursov", "given_name": "Nikolaj" }, { "family_name": "Costa", "given_name": "Enrico", "orcid": "0000-0003-4925-8523" }, { "family_name": "Egron", "given_name": "Elise", "orcid": "0000-0002-1532-4142" }, { "family_name": "Garcia", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Green", "given_name": "David A.", "orcid": "0000-0003-3189-9998" }, { "family_name": "Gurwell", "given_name": "Mark", "orcid": "0000-0003-0685-3621" }, { "family_name": "Ingram", "given_name": "Adam", "orcid": "0000-0002-5311-9078" }, { "family_name": "Kajava", "given_name": "Jari J. E.", "orcid": "0000-0002-3010-8333" }, { "family_name": "Kale", "given_name": "Ruta", "orcid": "0000-0003-1449-3718" }, { "family_name": "Kraus", "given_name": "Alex", "orcid": "0000-0002-4184-9372" }, { "family_name": "Malyshev", "given_name": "Denys", "orcid": "0000-0001-9689-2194" }, { "family_name": "Marin", "given_name": "Fr\u00e9d\u00e9ric", "orcid": "0000-0003-4952-0835" }, { "family_name": "Matt", "given_name": "Giorgio", "orcid": "0000-0002-2152-0916" }, { "family_name": "McCollough", "given_name": "Michael", "orcid": "0000-0002-8384-3374" }, { "family_name": "Mereminskiy", "given_name": "Ilya A.", "orcid": "0000-0001-8931-1320" }, { "family_name": "Nizhelsky", "given_name": "Nikolaj" }, { "family_name": "Piano", "given_name": "Giovanni", "orcid": "0000-0002-9332-5319" }, { "family_name": "Pilia", "given_name": "Maura", "orcid": "0000-0001-7397-8091" }, { "family_name": "Pittori", "given_name": "Carlotta", "orcid": "0000-0001-6661-9779" }, { "family_name": "Rao", "given_name": "Ramprasad", "orcid": "0000-0002-1407-7944" }, { "family_name": "Righini", "given_name": "Simona", "orcid": "0000-0001-7332-5138" }, { "family_name": "Soffitta", "given_name": "Paolo", "orcid": "0000-0002-7781-4104" }, { "family_name": "Shevchenko", "given_name": "Anton", "orcid": "0000-0003-3522-6037" }, { "family_name": "Svoboda", "given_name": "Jiri", "orcid": "0000-0003-2931-0742" }, { "family_name": "Tombesi", "given_name": "Francesco", "orcid": "0000-0002-6562-8654" }, { "family_name": "Trushkin", "given_name": "Sergei A.", "orcid": "0000-0002-7586-5856" }, { "family_name": "Tsybulev", "given_name": "Peter", "orcid": "0000-0001-5600-8018" }, { "family_name": "Ursini", "given_name": "Francesco", "orcid": "0000-0001-9442-7897" }, { "family_name": "Wu", "given_name": "Kinwah", "orcid": "0000-0002-7568-8765" }, { "family_name": "Agudo", "given_name": "Iv\u00e1n", "orcid": "0000-0002-3777-6182" }, { "family_name": "Antonelli", "given_name": "Lucio A.", "orcid": "0000-0002-5037-9034" }, { "family_name": "Bachetti", "given_name": "Matteo", "orcid": "0000-0002-4576-9337" }, { "family_name": "Baldini", "given_name": "Luca", "orcid": "0000-0002-9785-7726" }, { "family_name": "Baumgartner", "given_name": "Wayne H.", "clpid": "/0000-0002-5106-0463" }, { "family_name": "Bellazzini", "given_name": "Ronaldo", "orcid": "0000-0002-2469-7063" }, { "family_name": "Bongiorno", "given_name": "Stephen D.", "orcid": "0000-0002-0901-2097" }, { "family_name": "Bonino", "given_name": "Raffaella", "orcid": "0000-0002-4264-1215" }, { "family_name": "Brez", "given_name": "Alessandro", "orcid": "0000-0002-9460-1821" }, { "family_name": "Bucciantini", "given_name": "Niccol\u00f2", "orcid": "0000-0002-8848-1392" }, { "family_name": "Castellano", "given_name": "Simone", "orcid": "0000-0003-1111-4292" }, { "family_name": "Cavazzuti", "given_name": "Elisabetta", "orcid": "0000-0001-7150-9638" }, { "family_name": "Chen", "given_name": "Chien-Ting", "orcid": "0000-0002-4945-5079" }, { "family_name": "Ciprini", "given_name": "Stefano", "orcid": "0000-0002-0712-2479" }, { "family_name": "Del Monte", "given_name": "Ettore", "orcid": "0000-0002-3013-6334" }, { "family_name": "Di Gesu", "given_name": "Laura", "orcid": "0000-0002-5614-5028" }, { "family_name": "Di Lalla", "given_name": "Niccol\u00f2", "orcid": "0000-0002-7574-1298" }, { "family_name": "Donnarumma", "given_name": "Immacolata", "orcid": "0000-0002-4700-4549" }, { "family_name": "Doroshenko", "given_name": "Victor", "orcid": "0000-0001-8162-1105" }, { "family_name": "Ehlert", "given_name": "Steven R.", "orcid": "0000-0003-4420-2838" }, { "family_name": "Enoto", "given_name": "Teruaki", "orcid": "0000-0003-1244-3100" }, { "family_name": "Evangelista", "given_name": "Yuri", "orcid": "0000-0001-6096-6710" }, { "family_name": "Fabiani", "given_name": "Sergio", "orcid": "0000-0003-1533-0283" }, { "family_name": "Ferrazzoli", "given_name": "Riccardo", "orcid": "0000-0003-1074-8605" }, { "family_name": "Gunji", "given_name": "Shuichi", "orcid": "0000-0002-5881-2445" }, { "family_name": "Hayashida", "given_name": "Kiyoshi" }, { "family_name": "Heyl", "given_name": "Jeremy", "orcid": "0000-0001-9739-367X" }, { "family_name": "Iwakiri", "given_name": "Wataru", "orcid": "0000-0002-0207-9010" }, { "family_name": "Jorstad", "given_name": "Svetlana G.", "orcid": "0000-0001-6158-1708" }, { "family_name": "Karas", "given_name": "Vladimir", "orcid": "0000-0002-5760-0459" }, { "family_name": "Kislat", "given_name": "Fabian", "orcid": "0000-0001-7477-0380" }, { "family_name": "Kitaguchi", "given_name": "Takao" }, { "family_name": "Kolodziejczak", "given_name": "Jeffery J.", "orcid": "0000-0002-0110-6136" }, { "family_name": "Latronico", "given_name": "Luca", "orcid": "0000-0002-0984-1856" }, { "family_name": "Liodakis", "given_name": "Ioannis", "orcid": "0000-0001-9200-4006" }, { "family_name": "Maldera", "given_name": "Simone", "orcid": "0000-0002-0698-4421" }, { "family_name": "Manfreda", "given_name": "Alberto", "orcid": "0000-0002-0998-4953" }, { "family_name": "Marinucci", "given_name": "Andrea", "orcid": "0000-0002-2055-4946" }, { "family_name": "Marscher", "given_name": "Alan P.", "orcid": "0000-0001-7396-3332" }, { "family_name": "Marshall", "given_name": "Herman L.", "orcid": "0000-0002-6492-1293" }, { "family_name": "Massaro", "given_name": "Francesco", "orcid": "0000-0002-1704-9850" }, { "family_name": "Mitsuishi", "given_name": "Ikuyuki", "orcid": "0000-0002-9901-233X" }, { "family_name": "Mizuno", "given_name": "Tsunefumi", "orcid": "0000-0001-7263-0296" }, { "family_name": "Negro", "given_name": "Michela", "orcid": "0000-0002-6548-5622" }, { "family_name": "Ng", "given_name": "Chi-Yung", "orcid": "0000-0002-5847-2612" }, { "family_name": "O'Dell", "given_name": "Stephen L.", "orcid": "0000-0002-1868-8056" }, { "family_name": "Omodei", "given_name": "Nicola", "orcid": "0000-0002-5448-7577" }, { "family_name": "Oppedisano", "given_name": "Chiara", "orcid": "0000-0001-6194-4601" }, { "family_name": "Papitto", "given_name": "Alessandro", "orcid": "0000-0001-6289-7413" }, { "family_name": "Pavlov", "given_name": "George G.", "orcid": "0000-0002-7481-5259" }, { "family_name": "Peirson", "given_name": "Abel L.", "orcid": "0000-0001-6292-1911" }, { "family_name": "Perri", "given_name": "Matteo", "orcid": "0000-0003-3613-4409" }, { "family_name": "Pesce-Rollins", "given_name": "Melissa", "orcid": "0000-0003-1790-8018" }, { "family_name": "Petrucci", "given_name": "Pierre-Olivier", "orcid": "0000-0001-6061-3480" }, { "family_name": "Possenti", "given_name": "Andrea", "orcid": "0000-0001-5902-3731" }, { "family_name": "Puccetti", "given_name": "Simonetta", "orcid": "0000-0002-2734-7835" }, { "family_name": "Ramsey", "given_name": "Brian D.", "orcid": "0000-0003-1548-1524" }, { "family_name": "Rankin", "given_name": "John", "orcid": "0000-0002-9774-0560" }, { "family_name": "Roberts", "given_name": "Oliver", "orcid": "0000-0002-7150-9061" }, { "family_name": "Romani", "given_name": "Roger W.", "orcid": "0000-0001-6711-3286" }, { "family_name": "Sgr\u00f2", "given_name": "Carmelo", "orcid": "0000-0001-5676-6214" }, { "family_name": "Slane", "given_name": "Patrick", "orcid": "0000-0002-6986-6756" }, { "family_name": "Spandre", "given_name": "Gloria", "orcid": "0000-0003-0802-3453" }, { "family_name": "Swartz", "given_name": "Doug", "orcid": "0000-0002-2954-4461" }, { "family_name": "Tamagawa", "given_name": "Toru", "orcid": "0000-0002-8801-6263" }, { "family_name": "Tavecchio", "given_name": "Fabrizio", "orcid": "0000-0003-0256-0995" }, { "family_name": "Taverna", "given_name": "Roberto", "orcid": "0000-0002-1768-618X" }, { "family_name": "Tawara", "given_name": "Yuzuru" }, { "family_name": "Tennant", "given_name": "Allyn F.", "orcid": "0000-0002-9443-6774" }, { "family_name": "Thomas", "given_name": "Nicholas E." }, { "family_name": "Trois", "given_name": "Alessio", "orcid": "0000-0002-3180-6002" }, { "family_name": "Turolla", "given_name": "Roberto", "clpid": "/0000-0003-3977-8760" }, { "family_name": "Vink", "given_name": "Jacco", "orcid": "0000-0002-4708-4219" }, { "family_name": "Xie", "given_name": "Fei", "orcid": "0000-0002-0105-5826" }, { "family_name": "Zane", "given_name": "Silvia", "orcid": "0000-0001-5326-880X" } ], "abstract": "
\n
\n

The accretion of matter by compact objects can be inhibited by radiation pressure if the luminosity exceeds a critical value known as the Eddington limit. The discovery of ultraluminous X-ray sources has shown that accretion can proceed even when the apparent luminosity considerably exceeds this limit. A high apparent luminosity might be produced due to the geometric beaming of radiation by an outflow. The outflow half-opening angle, which determines the amplification due to beaming, has never been robustly constrained. Using the Imaging X-ray Polarimetry Explorer, we measured the X-ray polarization in the Galactic X-ray binary Cygnus X-3 (Cyg X-3). We found high, >20%, nearly energy-independent linear polarization orthogonal to the direction of the radio ejections. These properties unambiguously indicate the presence of a collimating outflow from the X-ray binary Cyg X-3 and constrain its half-opening angle to \u227215°. Thus, the source can be used as a laboratory for studying the supercritical accretion regime. This finding underscores the importance of X-ray polarimetry in advancing our understanding of accreting sources.

\n
\n
", "doi": "10.1038/s41550-024-02294-9", "issn": "2397-3366", "publisher": "Nature Publishing Group", "publication": "Nature Astronomy", "publication_date": "2024-08", "volume": "8", "pages": "1031-1046" }, { "id": "authors:wchce-m0146", "collection": "authors", "collection_id": "wchce-m0146", "cite_using_url": "https://authors.library.caltech.edu/records/wchce-m0146", "type": "article", "title": "Complex rotational dynamics of the neutron star in Hercules X-1 revealed by X-ray polarization", "author": [ { "family_name": "Heyl", "given_name": "Jeremy", "orcid": "0000-0001-9739-367X", "clpid": "Heyl-Jeremy-S" }, { "family_name": "Doroshenko", "given_name": "Victor", "orcid": "0000-0001-8162-1105" }, { "family_name": "Gonz\u00e1lez-Caniulef", "given_name": "Denis", "orcid": "0000-0001-5848-0180" }, { "family_name": "Caiazzo", "given_name": "Ilaria", "orcid": "0000-0002-4770-5388", "clpid": "Caiazzo-Ilaria" }, { "family_name": "Poutanen", "given_name": "Juri", "orcid": "0000-0002-0983-0049" }, { "family_name": "Mushtukov", "given_name": "Alexander", "orcid": "0000-0003-2306-419X" }, { "family_name": "Tsygankov", "given_name": "Sergey S.", "orcid": "0000-0002-9679-0793" }, { "family_name": "Kirmizibayrak", "given_name": "Demet", "orcid": "0000-0003-2675-740X" }, { "family_name": "Bachetti", "given_name": "Matteo", "orcid": "0000-0002-4576-9337" }, { "family_name": "Pavlov", "given_name": "George G.", "orcid": "0000-0002-7481-5259" }, { "family_name": "Forsblom", "given_name": "Sofia V.", "orcid": "0000-0001-9167-2790" }, { "family_name": "Malacaria", "given_name": "Christian", "orcid": "0000-0002-0380-0041" }, { "family_name": "Suleimanov", "given_name": "Valery F.", "orcid": "0000-0003-3733-7267" }, { "family_name": "Agudo", "given_name": "Iv\u00e1n", "orcid": "0000-0002-3777-6182" }, { "family_name": "Antonelli", "given_name": "Lucio Angelo", "orcid": "0000-0002-5037-9034" }, { "family_name": "Baldini", "given_name": "Luca", "orcid": "0000-0002-9785-7726" }, { "family_name": "Baumgartner", "given_name": "Wayne H.", "orcid": "0000-0002-5106-0463" }, { "family_name": "Bellazzini", "given_name": "Ronaldo", "orcid": "0000-0002-2469-7063" }, { "family_name": "Bianchi", "given_name": "Stefano", "orcid": "0000-0002-4622-4240" }, { "family_name": "Bongiorno", "given_name": "Stephen D.", "orcid": "0000-0002-0901-2097" }, { "family_name": "Bonino", "given_name": "Raffaella", "orcid": "0000-0002-4264-1215" }, { "family_name": "Brez", "given_name": "Alessandro", "orcid": "0000-0002-9460-1821" }, { "family_name": "Bucciantini", "given_name": "Niccol\u00f2", "orcid": "0000-0002-8848-1392" }, { "family_name": "Capitanio", "given_name": "Fiamma", "orcid": "0000-0002-6384-3027" }, { "family_name": "Castellano", "given_name": "Simone", "orcid": "0000-0003-1111-4292" }, { "family_name": "Cavazzuti", "given_name": "Elisabetta", "orcid": "0000-0001-7150-9638" }, { "family_name": "Chen", "given_name": "Chien-Ting", "orcid": "0000-0002-4945-5079" }, { "family_name": "Ciprini", "given_name": "Stefano", "orcid": "0000-0002-0712-2479" }, { "family_name": "Costa", "given_name": "Enrico", "orcid": "0000-0003-4925-8523" }, { "family_name": "De Rosa", "given_name": "Alessandra", "orcid": "0000-0001-5668-6863" }, { "family_name": "Del Monte", "given_name": "Ettore", "orcid": "0000-0002-3013-6334" }, { "family_name": "Di Gesu", "given_name": "Laura", "orcid": "0000-0002-5614-5028" }, { "family_name": "Di Lalla", "given_name": "Niccol\u00f2", "orcid": "0000-0002-7574-1298" }, { "family_name": "Di Marco", "given_name": "Alessandro", "orcid": "0000-0003-0331-3259" }, { "family_name": "Donnarumma", "given_name": "Immacolata", "orcid": "0000-0002-4700-4549" }, { "family_name": "Dov\u010diak", "given_name": "Michal", "orcid": "0000-0003-0079-1239" }, { "family_name": "Ehlert", "given_name": "Steven R.", "orcid": "0000-0003-4420-2838" }, { "family_name": "Enoto", "given_name": "Teruaki", "orcid": "0000-0003-1244-3100" }, { "family_name": "Evangelista", "given_name": "Yuri", "orcid": "0000-0001-6096-6710" }, { "family_name": "Fabiani", "given_name": "Sergio", "orcid": "0000-0003-1533-0283" }, { "family_name": "Ferrazzoli", "given_name": "Riccardo", "orcid": "0000-0003-1074-8605" }, { "family_name": "Garcia", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Gunji", "given_name": "Shuichi", "orcid": "0000-0002-5881-2445" }, { "family_name": "Hayashida", "given_name": "Kiyoshi" }, { "family_name": "Iwakiri", "given_name": "Wataru", "orcid": "0000-0002-0207-9010" }, { "family_name": "Jorstad", "given_name": "Svetlana G.", "orcid": "0000-0001-6158-1708" }, { "family_name": "Kaaret", "given_name": "Philip", "orcid": "0000-0002-3638-0637" }, { "family_name": "Karas", "given_name": "Vladimir", "orcid": "0000-0002-5760-0459" }, { "family_name": "Kislat", "given_name": "Fabian", "orcid": "0000-0001-7477-0380" }, { "family_name": "Kitaguchi", "given_name": "Takao" }, { "family_name": "Kolodziejczak", "given_name": "Jeffery J.", "orcid": "0000-0002-0110-6136" }, { "family_name": "Krawczynski", "given_name": "Henric", "orcid": "0000-0002-1084-6507" }, { "family_name": "La Monaca", "given_name": "Fabio", "orcid": "0000-0001-8916-4156" }, { "family_name": "Latronico", "given_name": "Luca", "orcid": "0000-0002-0984-1856" }, { "family_name": "Liodakis", "given_name": "Ioannis", "orcid": "0000-0001-9200-4006" }, { "family_name": "Maldera", "given_name": "Simone", "orcid": "0000-0002-0698-4421" }, { "family_name": "Manfreda", "given_name": "Alberto", "orcid": "0000-0002-0998-4953" }, { "family_name": "Marin", "given_name": "Fr\u00e9d\u00e9ric", "orcid": "0000-0003-4952-0835" }, { "family_name": "Marinucci", "given_name": "Andrea", "orcid": "0000-0002-2055-4946" }, { "family_name": "Marscher", "given_name": "Alan P.", "orcid": "0000-0001-7396-3332" }, { "family_name": "Marshall", "given_name": "Herman L.", "orcid": "0000-0002-6492-1293" }, { "family_name": "Massaro", "given_name": "Francesco", "orcid": "0000-0002-1704-9850" }, { "family_name": "Matt", "given_name": "Giorgio", "orcid": "0000-0002-2152-0916" }, { "family_name": "Mitsuishi", "given_name": "Ikuyuki", "orcid": "0000-0002-9901-233X" }, { "family_name": "Mizuno", "given_name": "Tsunefumi", "orcid": "0000-0001-7263-0296" }, { "family_name": "Muleri", "given_name": "Fabio", "orcid": "0000-0003-3331-3794" }, { "family_name": "Negro", "given_name": "Michela", "orcid": "0000-0002-6548-5622" }, { "family_name": "Ng", "given_name": "C.-Y.", "orcid": "0000-0002-5847-2612" }, { "family_name": "O'Dell", "given_name": "Stephen L.", "orcid": "0000-0002-1868-8056" }, { "family_name": "Omodei", "given_name": "Nicola", "orcid": "0000-0002-5448-7577" }, { "family_name": "Oppedisano", "given_name": "Chiara", "orcid": "0000-0001-6194-4601" }, { "family_name": "Papitto", "given_name": "Alessandro", "orcid": "0000-0001-6289-7413" }, { "family_name": "Peirson", "given_name": "Abel Lawrence", "orcid": "0000-0001-6292-1911" }, { "family_name": "Perri", "given_name": "Matteo", "orcid": "0000-0003-3613-4409" }, { "family_name": "Pesce-Rollins", "given_name": "Melissa", "orcid": "0000-0003-1790-8018" }, { "family_name": "Petrucci", "given_name": "Pierre-Olivier", "orcid": "0000-0001-6061-3480" }, { "family_name": "Pilia", "given_name": "Maura", "orcid": "0000-0001-7397-8091" }, { "family_name": "Possenti", "given_name": "Andrea", "orcid": "0000-0001-5902-3731" }, { "family_name": "Puccetti", "given_name": "Simonetta", "orcid": "0000-0002-2734-7835" }, { "family_name": "Ramsey", "given_name": "Brian D.", "orcid": "0000-0003-1548-1524" }, { "family_name": "Rankin", "given_name": "John", "orcid": "0000-0002-9774-0560" }, { "family_name": "Ratheesh", "given_name": "Ajay", "orcid": "0000-0003-0411-4243" }, { "family_name": "Roberts", "given_name": "Oliver J.", "orcid": "0000-0002-7150-9061" }, { "family_name": "Romani", "given_name": "Roger W.", "orcid": "0000-0001-6711-3286" }, { "family_name": "Sgr\u00f2", "given_name": "Carmelo", "orcid": "0000-0001-5676-6214" }, { "family_name": "Slane", "given_name": "Patrick", "orcid": "0000-0002-6986-6756" }, { "family_name": "Soffitta", "given_name": "Paolo", "orcid": "0000-0002-7781-4104" }, { "family_name": "Spandre", "given_name": "Gloria", "orcid": "0000-0003-0802-3453" }, { "family_name": "Swartz", "given_name": "Douglas A.", "orcid": "0000-0002-2954-4461" }, { "family_name": "Tamagawa", "given_name": "Toru", "orcid": "0000-0002-8801-6263" }, { "family_name": "Tavecchio", "given_name": "Fabrizio", "orcid": "0000-0003-0256-0995" }, { "family_name": "Taverna", "given_name": "Roberto", "orcid": "0000-0002-1768-618X" }, { "family_name": "Tawara", "given_name": "Yuzuru" }, { "family_name": "Tennant", "given_name": "Allyn F.", "orcid": "0000-0002-9443-6774" }, { "family_name": "Thomas", "given_name": "Nicholas E." }, { "family_name": "Tombesi", "given_name": "Francesco", "orcid": "0000-0002-6562-8654" }, { "family_name": "Trois", "given_name": "Alessio", "orcid": "0000-0002-3180-6002" }, { "family_name": "Turolla", "given_name": "Roberto", "orcid": "0000-0003-3977-8760" }, { "family_name": "Vink", "given_name": "Jacco", "orcid": "0000-0002-4708-4219" }, { "family_name": "Weisskopf", "given_name": "Martin C.", "orcid": "0000-0002-5270-4240" }, { "family_name": "Wu", "given_name": "Kinwah", "orcid": "0000-0002-7568-8765" }, { "family_name": "Xie", "given_name": "Fei", "orcid": "0000-0002-0105-5826" }, { "family_name": "Zane", "given_name": "Silvia", "orcid": "0000-0001-5326-880X" } ], "abstract": "
\n
\n

In an accreting X-ray pulsar, a neutron star accretes matter from a companion star through an accretion disk. The magnetic field of the rotating neutron star disrupts the inner edge of the disk, funnelling the gas to flow onto the poles on its surface. Hercules X-1 is a prototypical persistent X-ray pulsar about 7 kpc from Earth. Its emission varies on three distinct timescales: the neutron star rotates every 1.2 s, it is eclipsed by its companion each 1.7 d, and the system exhibits a superorbital period of 35 d, which has remained stable since its discovery. Several lines of evidence point to the source of this variation as the precession of the accretion disk or that of the neutron star. Despite the many hints over the past 50 yr, the precession of the neutron star itself has yet not been confirmed or refuted. X-ray polarization measurements (probing the spin geometry of Her X-1) with the Imaging X-ray Polarimetry Explorer suggest that free precession of the neutron star crust sets the 35 d period; this has the important implication that its crust is somewhat asymmetric by a few parts per ten million.

\n
\n
", "doi": "10.1038/s41550-024-02295-8", "issn": "2397-3366", "publisher": "Nature Publishing Group", "publication": "Nature Astronomy", "publication_date": "2024-08", "volume": "8", "pages": "1047-1053" }, { "id": "authors:8rmpn-t8z76", "collection": "authors", "collection_id": "8rmpn-t8z76", "cite_using_url": "https://authors.library.caltech.edu/records/8rmpn-t8z76", "type": "article", "title": "Investigating the Ultracompact X-Ray Binary Candidate SLX 1735-269 with NICER and NuSTAR", "author": [ { "family_name": "Moutard", "given_name": "D. L.", "orcid": "0000-0003-1463-8702", "clpid": "Moutard-David-L" }, { "family_name": "Ludlam", "given_name": "R. M.", "orcid": "0000-0002-8961-939X", "clpid": "Ludlam-Renee-M" }, { "family_name": "Sudha", "given_name": "M.", "orcid": "0000-0003-0440-7978", "clpid": "Sudha-Malu" }, { "family_name": "Buisson", "given_name": "D. J. K.", "clpid": "Buisson-D-J-K" }, { "family_name": "Cackett", "given_name": "E. M.", "orcid": "0000-0002-8294-9281", "clpid": "Cackett-Edward-M" }, { "family_name": "Degenaar", "given_name": "N.", "orcid": "0000-0002-0092-3548", "clpid": "Degenaar-Nathalie" }, { "family_name": "Fabian", "given_name": "A. C.", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-Andrew-C" }, { "family_name": "Gandhi", "given_name": "P.", "orcid": "0000-0003-3105-2615", "clpid": "Gandhi-Poshak" }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Shaw", "given_name": "A. W.", "orcid": "0000-0002-8808-520X", "clpid": "Shaw-Aarran-W" }, { "family_name": "Tomsick", "given_name": "J. A.", "orcid": "0000-0001-5506-9855", "clpid": "Tomsick-John-A" } ], "abstract": "

We present two simultaneous NICER and NuSTAR observations of the ultracompact X-ray binary (UCXB) candidate SLX 1735−269 while the source was in two different spectral states. Using various reflection modeling techniques, we find that xillverCO, a model used for fitting X-ray spectra of UCXBs with high carbon and oxygen abundances is an improvement over relxill or relxillNS, which instead contains solar-like chemical abundances. This provides indirect evidence in support of the source being ultracompact. We also use this reflection model to get a preliminary measurement of the inclination of the system, \ud835\udc56=57\u208b\u2087\u207a²³ degrees. This is consistent with our timing analysis, where a lack of eclipses indicates an inclination of i < 80°. The timing analysis is otherwise inconclusive, and we cannot confidently measure the orbital period of the system.

", "doi": "10.3847/1538-4357/ad4a78", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2024-06-20", "series_number": "2", "volume": "968", "issue": "2", "pages": "51" }, { "id": "authors:4605g-89v12", "collection": "authors", "collection_id": "4605g-89v12", "cite_using_url": "https://authors.library.caltech.edu/records/4605g-89v12", "type": "article", "title": "Dramatic Drop in the X-Ray Polarization of Swift J1727.8\u20131613 in the Soft Spectral State", "author": [ { "family_name": "Svoboda", "given_name": "Ji\u0159\u00ed", "orcid": "0000-0003-2931-0742", "clpid": "Svoboda-Ji\u0159\u00ed" }, { "family_name": "Dov\u010diak", "given_name": "Michal", "orcid": "0000-0003-0079-1239" }, { "family_name": "Steiner", "given_name": "James F.", "orcid": "0000-0002-5872-6061" }, { "family_name": "Kaaret", "given_name": "Philip", "orcid": "0000-0002-3638-0637" }, { "family_name": "Podgorn\u00fd", "given_name": "Jakub", "orcid": "0000-0001-5418-291X" }, { "family_name": "Poutanen", "given_name": "Juri", "orcid": "0000-0002-0983-0049" }, { "family_name": "Veledina", "given_name": "Alexandra", "orcid": "0000-0002-5767-7253" }, { "family_name": "Muleri", "given_name": "Fabio", "orcid": "0000-0003-3331-3794" }, { "family_name": "Taverna", "given_name": "Roberto", "orcid": "0000-0002-1768-618X" }, { "family_name": "Krawczynski", "given_name": "Henric", "orcid": "0000-0002-1084-6507" }, { "family_name": "Brigitte", "given_name": "Ma\u00efmouna", "orcid": "0009-0004-1197-5935" }, { "family_name": "Datta", "given_name": "Sudeb Ranjan", "orcid": "0000-0001-5975-1026" }, { "family_name": "Bianchi", "given_name": "Stefano", "orcid": "0000-0002-4622-4240" }, { "family_name": "Mu\u00f1oz-Darias", "given_name": "Teo", "orcid": "0000-0002-3348-4035" }, { "family_name": "Negro", "given_name": "Michela", "orcid": "0000-0002-6548-5622" }, { "family_name": "Rodriguez Cavero", "given_name": "Nicole", "orcid": "0000-0001-5256-0278" }, { "family_name": "Castro Segura", "given_name": "Noel", "orcid": "0000-0002-5870-0443" }, { "family_name": "Bollemeijer", "given_name": "Niek", "orcid": "0009-0005-6609-5852" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Ingram", "given_name": "Adam", "orcid": "0000-0002-5311-9078" }, { "family_name": "Matt", "given_name": "Giorgio", "orcid": "0000-0002-2152-0916" }, { "family_name": "Nathan", "given_name": "Edward", "orcid": "0000-0002-9633-9193", "clpid": "Nathan-Edward" }, { "family_name": "Weisskopf", "given_name": "Martin C.", "orcid": "0000-0002-5270-4240" }, { "family_name": "Altamirano", "given_name": "Diego", "orcid": "0000-0002-3422-0074" }, { "family_name": "Baldini", "given_name": "Luca", "orcid": "0000-0002-9785-7726" }, { "family_name": "Capitanio", "given_name": "Fiamma", "orcid": "0000-0002-6384-3027" }, { "family_name": "Egron", "given_name": "Elise", "orcid": "0000-0002-1532-4142" }, { "family_name": "Emami", "given_name": "Razieh", "orcid": "0000-0002-2791-5011" }, { "family_name": "Hu", "given_name": "Kun", "orcid": "0000-0002-9705-7948" }, { "family_name": "Marra", "given_name": "Lorenzo", "orcid": "0009-0001-4644-194X" }, { "family_name": "Mastroserio", "given_name": "Guglielmo", "orcid": "0000-0003-4216-7936" }, { "family_name": "Petrucci", "given_name": "Pierre-Olivier", "orcid": "0000-0001-6061-3480" }, { "family_name": "Ratheesh", "given_name": "Ajay", "orcid": "0000-0003-0411-4243" }, { "family_name": "Soffitta", "given_name": "Paolo", "orcid": "0000-0002-7781-4104" }, { "family_name": "Tombesi", "given_name": "Francesco", "orcid": "0000-0002-6562-8654" }, { "family_name": "Yang", "given_name": "Yi-Jung", "orcid": "0000-0001-9108-573X" }, { "family_name": "Zhang", "given_name": "Yuexin", "orcid": "0000-0002-2268-9318" } ], "abstract": "
\n

Black hole X-ray binaries exhibit different spectral and timing properties in different accretion states. The X-ray outburst of a recently discovered and extraordinarily bright source, Swift J1727.8–1613, has enabled the first investigation of how the X-ray polarization properties of a source evolve with spectral state. The 2–8 keV polarization degree was previously measured by the Imaging X-ray Polarimetry Explorer (IXPE) to be ≈4% in the hard and hard intermediate states. Here we present new IXPE results taken in the soft state, with the X-ray flux dominated by the thermal accretion disk emission. We find that the polarization degree has dropped dramatically to \u22721%. This result indicates that the measured X-ray polarization is largely sensitive to the accretion state and the polarization fraction is significantly higher in the hard state when the X-ray emission is dominated by upscattered radiation in the X-ray corona. The combined polarization measurements in the soft and hard states disfavor a very high or low inclination of the system.

\n
", "doi": "10.3847/2041-8213/ad402e", "issn": "2041-8205", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal Letters", "publication_date": "2024-05-10", "series_number": "2", "volume": "966", "issue": "2", "pages": "L35" }, { "id": "authors:shbsj-86a60", "collection": "authors", "collection_id": "shbsj-86a60", "cite_using_url": "https://authors.library.caltech.edu/records/shbsj-86a60", "type": "article", "title": "Elemental Abundances in the Diffuse Interstellar Medium from Joint Far-ultraviolet and X-Ray Spectroscopy: Iron, Oxygen, Carbon, and Sulfur", "author": [ { "family_name": "Psaradaki", "given_name": "I.", "orcid": "0000-0002-1049-3182", "clpid": "Psaradaki-Ioanna" }, { "family_name": "Corrales", "given_name": "L.", "orcid": "0000-0002-5466-3817", "clpid": "Corrales-Lia" }, { "family_name": "Werk", "given_name": "J.", "orcid": "0000-0002-0355-0134", "clpid": "Werk-Jessica" }, { "family_name": "Jensen", "given_name": "A. G.", "clpid": "Jensen-A-G" }, { "family_name": "Costantini", "given_name": "E.", "clpid": "Costantini-E" }, { "family_name": "Mehdipour", "given_name": "M.", "orcid": "0000-0002-4992-4664", "clpid": "Mehdipour-Missagh" }, { "family_name": "Cilley", "given_name": "R.", "orcid": "0009-0009-0960-6280", "clpid": "Cilley-Raven" }, { "family_name": "Schulz", "given_name": "N.", "clpid": "Schulz-N" }, { "family_name": "Kaastra", "given_name": "J.", "orcid": "0000-0001-5540-2822", "clpid": "Kaastra-Jelle" }, { "family_name": "Garcia", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Valencic", "given_name": "L.", "clpid": "Valencic-L" }, { "family_name": "Kallman", "given_name": "T.", "clpid": "Kallman-T" }, { "family_name": "Paerels", "given_name": "F.", "orcid": "0000-0001-9225-6481", "clpid": "Paerels-Frederik-B-S" } ], "abstract": "
\n

In this study, we investigate interstellar absorption lines along the line of sight toward the galactic low-mass X-ray binary Cygnus X-2. We combine absorption line data obtained from high-resolution X-ray spectra collected with the Chandra and XMM-Newton satellites, along with far-UV absorption lines observed by the Hubble Space Telescope's (HST) Cosmic Origins Spectrograph (COS) instrument. Our primary objective is to understand the abundance and depletion of oxygen, iron, sulfur, and carbon. To achieve this, we have developed an analysis pipeline that simultaneously fits both the UV and X-ray data sets. This novel approach takes into account the line-spread function of HST/COS, enhancing the precision of our results. We examine the absorption lines of Fe ii, S ii, C ii, and C i present in the far-UV spectrum of Cygnus X-2, revealing the presence of at least two distinct absorbers characterized by different velocities. Additionally, we employ Cloudy simulations to compare our findings concerning the ionic ratios for the studied elements. We find that gaseous iron and sulfur exist in their singly ionized forms, Fe ii and S ii, respectively, while the abundances of C ii and C i do not agree with the Cloudy simulations of the neutral ISM. Finally, we explore discrepancies in the X-ray atomic data of iron and discuss their impact on the overall abundance and depletion of iron.

\n
", "doi": "10.3847/1538-3881/ad306b", "issn": "0004-6256", "publisher": "American Astronomical Society", "publication": "Astronomical Journal", "publication_date": "2024-05", "series_number": "5", "volume": "167", "issue": "5", "pages": "217" }, { "id": "authors:g33ae-8hz36", "collection": "authors", "collection_id": "g33ae-8hz36", "cite_using_url": "https://authors.library.caltech.edu/records/g33ae-8hz36", "type": "article", "title": "Toward More Accurate Synthetic Reflection Spectra: Improving the Calculations of Returning Radiation", "author": [ { "family_name": "Mirzaev", "given_name": "Temurbek", "orcid": "0000-0002-9337-4612", "clpid": "Mirzaev-Temurbek" }, { "family_name": "Riaz", "given_name": "Shafqat", "orcid": "0000-0003-3518-0235", "clpid": "Riaz-Shafqat" }, { "family_name": "Abdikamalov", "given_name": "Askar B.", "orcid": "0000-0002-7671-6457", "clpid": "Abdikamalov-Askar-B" }, { "family_name": "Bambi", "given_name": "Cosimo", "orcid": "0000-0002-3180-9502", "clpid": "Bambi-Cosimo" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-Thomas" }, { "family_name": "Garcia", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Jiang", "given_name": "Jiachen", "orcid": "0000-0002-9639-4352", "clpid": "Jiang-Jiachen" }, { "family_name": "Liu", "given_name": "Honghui", "orcid": "0000-0003-2845-1009", "clpid": "Liu-Honghui" }, { "family_name": "Shashank", "given_name": "Swarnim", "orcid": "0000-0003-3402-7212", "clpid": "Shashank-Swarnim" } ], "abstract": "Abstract\n We present a new model to calculate reflection spectra of thin accretion disks in Kerr spacetimes. Our model includes the effect of returning radiation, which is the radiation that is emitted by the disk and returns to the disk because of the strong light bending near a black hole. The major improvement with respect to the existing models is that it calculates the reflection spectrum at every point on the disk by using the actual spectrum of the incident radiation. Assuming a lamppost coronal geometry, we simulate simultaneous observations of NICER and NuSTAR of bright Galactic black holes and we fit the simulated data with the latest version of relxill (modified to read the table of reflionx, which is the nonrelativistic reflection model used in our calculations). We find that relxill with returning radiation cannot fit well the simulated data when the black hole spin parameter is very high and the coronal height and disk's ionization parameter are low, and some parameters can be significantly overestimated or underestimated. We can find better fits and recover the correct input parameters as the value of the black hole spin parameter decreases and the value of the coronal height increases.", "doi": "10.3847/1538-4357/ad303b", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2024-04-10", "series_number": "1", "volume": "965", "issue": "1", "pages": "66" }, { "id": "authors:0ep0c-zra90", "collection": "authors", "collection_id": "0ep0c-zra90", "cite_using_url": "https://authors.library.caltech.edu/records/0ep0c-zra90", "type": "article", "title": "Highly Coherent Quasiperiodic Oscillations in the \"Heartbeat\" Black Hole X-Ray Binary IGR J17091\u20133624", "author": [ { "family_name": "Wang", "given_name": "Jingyi", "orcid": "0000-0002-1742-2125", "clpid": "Wang-Jingyi" }, { "family_name": "Kara", "given_name": "Erin", "orcid": "0000-0003-0172-0854", "clpid": "Kara-Erin" }, { "family_name": "Homan", "given_name": "Jeroen", "orcid": "0000-0001-8371-2713", "clpid": "Homan-Jeroen" }, { "family_name": "Steiner", "given_name": "James F.", "orcid": "0000-0002-5872-6061", "clpid": "Steiner-James-F" }, { "family_name": "Altamirano", "given_name": "Diego", "orcid": "0000-0002-3422-0074", "clpid": "Altamirano-Diego" }, { "family_name": "Belloni", "given_name": "Tomaso", "orcid": "0000-0001-9621-3796", "clpid": "Belloni-Tomaso" }, { "family_name": "van der Klis", "given_name": "Michiel", "orcid": "0000-0003-0070-9872", "clpid": "van-der-Klis-Michiel" }, { "family_name": "Ingram", "given_name": "Adam", "orcid": "0000-0002-5311-9078", "clpid": "Ingram-Adam" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Mastroserio", "given_name": "Guglielmo", "orcid": "0000-0003-4216-7936", "clpid": "Mastroserio-Guglielmo" }, { "family_name": "Connors", "given_name": "Riley", "orcid": "0000-0002-8908-759X", "clpid": "Connors-Riley" }, { "family_name": "Lucchini", "given_name": "Matteo", "orcid": "0000-0002-2235-3347", "clpid": "Lucchini-Matteo" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-Thomas" }, { "family_name": "Neilsen", "given_name": "Joseph", "orcid": "0000-0002-8247-786X", "clpid": "Neilsen-Joseph" }, { "family_name": "Lewin", "given_name": "Collin", "orcid": "0000-0002-8671-1190", "clpid": "Lewin-Collin" }, { "family_name": "Remillard", "given_name": "Ron A.", "orcid": "0000-0003-4815-0481", "clpid": "Remillard-Ron-A" } ], "abstract": "
\n

IGR J17091–3624 is a black hole X-ray binary (BHXB), often referred to as the \"twin\" of GRS 1915+105 because it is the only other known BHXB that can show exotic \"heartbeat\"-like variability that is highly structured and repeated. Here, we report on observations of IGR J17091–3624 from its 2022 outburst, where we detect an unusually coherent quasiperiodic oscillation (QPO) when the broadband variability is low (total fractional rms \u22726%) and the spectrum is dominated by the accretion disk. Such spectral and variability behavior is characteristic of the soft state of typical BHXBs (i.e., those that do not show heartbeats), but we also find that this QPO is strongest when there is some exotic heartbeat-like variability (so-called Class V variability). This QPO is detected at frequencies between 5 and 8 Hz and has Q factors (defined as the QPO frequency divided by the width) \u227350, making it one of the most highly coherent low-frequency QPOs ever seen in a BHXB. The extremely high Q factor makes this QPO distinct from typical low-frequency QPOs that are conventionally classified into type-A/B/C QPOs. Instead, we find evidence that archival observations of GRS 1915+105 also showed a similarly high-coherence QPO in the same frequency range, suggesting that this unusually coherent and strong QPO may be unique to BHXBs that can exhibit \"heartbeat\"-like variability.

\n
", "doi": "10.3847/1538-4357/ad1fee", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2024-03-10", "series_number": "2", "volume": "963", "issue": "2", "pages": "118" }, { "id": "authors:137nm-8h269", "collection": "authors", "collection_id": "137nm-8h269", "cite_using_url": "https://authors.library.caltech.edu/records/137nm-8h269", "type": "article", "title": "The 2022 Outburst of IGR J17091\u20133624: Connecting the Exotic GRS 1915+105 to Standard Black Hole X-Ray Binaries", "author": [ { "family_name": "Wang", "given_name": "Jingyi", "orcid": "0000-0002-1742-2125", "clpid": "Wang-Jingyi" }, { "family_name": "Kara", "given_name": "Erin", "orcid": "0000-0003-0172-0854", "clpid": "Kara-Erin" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Altamirano", "given_name": "Diego", "orcid": "0000-0002-3422-0074", "clpid": "Altamirano-Diego" }, { "family_name": "Belloni", "given_name": "Tomaso", "orcid": "0000-0001-9621-3796", "clpid": "Belloni-Tomaso" }, { "family_name": "Steiner", "given_name": "James F.", "orcid": "0000-0002-5872-6061", "clpid": "Steiner-James-F" }, { "family_name": "van der Klis", "given_name": "Michiel", "orcid": "0000-0003-0070-9872", "clpid": "van-der-Klis-Michiel" }, { "family_name": "Ingram", "given_name": "Adam", "orcid": "0000-0002-5311-9078", "clpid": "Ingram-Adam" }, { "family_name": "Mastroserio", "given_name": "Guglielmo", "orcid": "0000-0003-4216-7936", "clpid": "Mastroserio-Guglielmo" }, { "family_name": "Connors", "given_name": "Riley", "orcid": "0000-0002-8908-759X", "clpid": "Connors-Riley" }, { "family_name": "Lucchini", "given_name": "Matteo", "orcid": "0000-0002-2235-3347", "clpid": "Lucchini-Matteo" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-Thomas" }, { "family_name": "Neilsen", "given_name": "Joseph", "orcid": "0000-0002-8247-786X", "clpid": "Neilsen-Joseph" }, { "family_name": "Lewin", "given_name": "Collin", "orcid": "0000-0002-8671-1190", "clpid": "Lewin-Collin" }, { "family_name": "Remillard", "given_name": "Ron A.", "orcid": "0000-0003-4815-0481", "clpid": "Remillard-Ron-A" }, { "family_name": "Homan", "given_name": "Jeroen", "orcid": "0000-0001-8371-2713", "clpid": "Homan-Jeroen" } ], "abstract": "
\n

While the standard X-ray variability of black hole X-ray binaries (BHXBs) is stochastic and noisy, there are two known BHXBs that exhibit exotic \"heartbeat\"-like variability in their lightcurves: GRS 1915+105 and IGR J17091–3624. In 2022, IGR J17091–3624 went into outburst for the first time in the NICER/NuSTAR era. These exquisite data allow us to simultaneously track the exotic variability and the corresponding spectral features with unprecedented detail. We find that as in typical BHXBs, the outburst began in the hard state, then continued in the intermediate state, but then transitioned to an exotic soft state, where we identify two types of heartbeat-like variability (Class V and a new Class X). The flux energy spectra show a broad iron emission line due to relativistic reflection when there is no exotic variability, and absorption features from highly ionized iron when the source exhibits exotic variability. Whether absorption lines from highly ionized iron are detected in IGR J17091–3624 is not determined by the spectral state alone, but rather is determined by the presence of exotic variability; in a soft spectral state, absorption lines are only detected along with exotic variability. Our finding indicates that IGR J17091–3624 can be seen as a bridge between the most peculiar BHXB GRS 1915+105 and \"normal\" BHXBs, because it alternates between the conventional and exotic behaviors of BHXBs. We discuss the physical nature of the absorbing material and exotic variability in light of this new legacy data set.

\n
", "doi": "10.3847/1538-4357/ad1595", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2024-03-01", "series_number": "1", "volume": "963", "issue": "1", "pages": "14" }, { "id": "authors:zm9k0-pvb36", "collection": "authors", "collection_id": "zm9k0-pvb36", "cite_using_url": "https://authors.library.caltech.edu/records/zm9k0-pvb36", "type": "article", "title": "Measuring black hole spins through X-ray reflection spectroscopy and the relativistic precession model: the case of XTE J1859+226", "author": [ { "family_name": "Mall", "given_name": "Gitika", "orcid": "0000-0003-2426-9808" }, { "family_name": "Liu", "given_name": "Honghui", "orcid": "0000-0003-2845-1009" }, { "family_name": "Bambi", "given_name": "Cosimo", "orcid": "0000-0002-3180-9502" }, { "family_name": "Steiner", "given_name": "James F", "orcid": "0000-0002-5872-6061" }, { "family_name": "Garc\u00eda", "given_name": "Javier A", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" } ], "abstract": "

The development of techniques to measure accurately black hole spins is crucial to study the physics and astrophysics of these objects. X-ray reflection spectroscopy is currently the most popular method to estimate the spins of accreting black holes; so far it has provided a spin measurement of about 40 stellar-mass black holes in X-ray binaries and 40 supermassive black holes in active galactic nuclei. The relativistic precession model (RPM) is another method to measure the spins of stellar-mass black holes: it requires the measurement of the frequencies of three simultaneous quasi-periodic oscillations and can potentially provide precise estimates of the black hole mass and spin. However, the two methods do not seem to provide consistent results when applied to the same sources, which questions the reliability and accuracy of these measurements. Recently, the RPM has been applied to infer the spin of the black hole in XTE J1859+226. The authors found a* = 0.149 ± 0.005 (68  per cent CL). There are no other spin measurements of this source. We looked for archived RXTE observations of XTE J1859+226 with blurred reflection features and found 23 spectra suitable for measuring the spin. We employed two different models with relxill and relxillD and obtained a higher spin value from all these fits. From simultaneous fitting of seven spectra of higher quality, we found $a_* = 0.986^{+0.001}_{-0.004}$ and a* = 0.987 ± 0.003 (90  per cent CL, statistical) with relxill and relxillD, respectively. Our results confirm the discrepancy between the spin measurements inferred from the two techniques.

", "doi": "10.1093/mnras/stad3933", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2024-02", "series_number": "4", "volume": "527", "issue": "4", "pages": "12053-12064" }, { "id": "authors:frszs-70f17", "collection": "authors", "collection_id": "frszs-70f17", "cite_using_url": "https://authors.library.caltech.edu/records/frszs-70f17", "type": "article", "title": "X-Ray Polarization of the Eastern Lobe of SS 433", "author": [ { "family_name": "Kaaret", "given_name": "Philip", "orcid": "0000-0002-3638-0637", "clpid": "Kaaret-Philip" }, { "family_name": "Ferrazzoli", "given_name": "Riccardo", "orcid": "0000-0003-1074-8605" }, { "family_name": "Silvestri", "given_name": "Stefano", "orcid": "0000-0002-8665-0105" }, { "family_name": "Negro", "given_name": "Michela", "orcid": "0000-0002-6548-5622" }, { "family_name": "Manfreda", "given_name": "Alberto", "orcid": "0000-0002-0998-4953" }, { "family_name": "Wu", "given_name": "Kinwah", "orcid": "0000-0002-7568-8765" }, { "family_name": "Costa", "given_name": "Enrico", "orcid": "0000-0003-4925-8523" }, { "family_name": "Soffitta", "given_name": "Paolo", "orcid": "0000-0002-7781-4104" }, { "family_name": "Safi-Harb", "given_name": "Samar", "orcid": "0000-0001-6189-7665" }, { "family_name": "Poutanen", "given_name": "Juri", "orcid": "0000-0002-0983-0049" }, { "family_name": "Veledina", "given_name": "Alexandra", "orcid": "0000-0002-5767-7253" }, { "family_name": "Di Marco", "given_name": "Alessandro", "orcid": "0000-0003-0331-3259" }, { "family_name": "Slane", "given_name": "Patrick", "orcid": "0000-0002-6986-6756" }, { "family_name": "Bianchi", "given_name": "Stefano", "orcid": "0000-0002-4622-4240" }, { "family_name": "Ingram", "given_name": "Adam", "orcid": "0000-0002-5311-9078" }, { "family_name": "Romani", "given_name": "Roger W.", "orcid": "0000-0001-6711-3286" }, { "family_name": "Cibrario", "given_name": "Nicol\u00f2", "orcid": "0000-0003-3842-4493" }, { "family_name": "Mac Intyre", "given_name": "Brydyn" }, { "family_name": "Mikus\u0306incov\u00e1", "given_name": "Romana", "orcid": "0000-0001-7374-843X" }, { "family_name": "Ratheesh", "given_name": "Ajay", "orcid": "0000-0003-0411-4243" }, { "family_name": "Steiner", "given_name": "James F.", "orcid": "0000-0002-5872-6061" }, { "family_name": "Svoboda", "given_name": "Jiri", "orcid": "0000-0003-2931-0742" }, { "family_name": "Tugliani", "given_name": "Stefano", "orcid": "0000-0002-3318-9036" }, { "family_name": "Agudo", "given_name": "Iv\u00e1n", "orcid": "0000-0002-3777-6182" }, { "family_name": "Antonelli", "given_name": "Lucio A.", "orcid": "0000-0002-5037-9034" }, { "family_name": "Bachetti", "given_name": "Matteo", "orcid": "0000-0002-4576-9337" }, { "family_name": "Baldini", "given_name": "Luca", "orcid": "0000-0002-9785-7726" }, { "family_name": "Baumgartner", "given_name": "Wayne H.", "orcid": "0000-0002-5106-0463" }, { "family_name": "Bellazzini", "given_name": "Ronaldo", "orcid": "0000-0002-2469-7063" }, { "family_name": "Bongiorno", "given_name": "Stephen D.", "orcid": "0000-0002-0901-2097" }, { "family_name": "Bonino", "given_name": "Raffaella", "orcid": "0000-0002-4264-1215" }, { "family_name": "Brez", "given_name": "Alessandro", "orcid": "0000-0002-9460-1821" }, { "family_name": "Bucciantini", "given_name": "Niccol\u00f2", "orcid": "0000-0002-8848-1392" }, { "family_name": "Capitanio", "given_name": "Fiamma", "orcid": "0000-0002-6384-3027" }, { "family_name": "Castellano", "given_name": "Simone", "orcid": "0000-0003-1111-4292" }, { "family_name": "Cavazzuti", "given_name": "Elisabetta", "orcid": "0000-0001-7150-9638" }, { "family_name": "Chen", "given_name": "Chien-Ting", "orcid": "0000-0002-4945-5079" }, { "family_name": "Ciprini", "given_name": "Stefano", "orcid": "0000-0002-0712-2479" }, { "family_name": "De Rosa", "given_name": "Alessandra", "orcid": "0000-0001-5668-6863" }, { "family_name": "Del Monte", "given_name": "Ettore", "orcid": "0000-0002-3013-6334" }, { "family_name": "Di Gesu", "given_name": "Laura", "orcid": "0000-0002-5614-5028" }, { "family_name": "Di Lalla", "given_name": "Niccol\u00f2", "orcid": "0000-0002-7574-1298" }, { "family_name": "Donnarumma", "given_name": "Immacolata", "orcid": "0000-0002-4700-4549" }, { "family_name": "Doroshenko", "given_name": "Victor", "orcid": "0000-0001-8162-1105" }, { "family_name": "Dov\u010diak", "given_name": "Michal", "orcid": "0000-0003-0079-1239" }, { "family_name": "Ehlert", "given_name": "Steven R.", "orcid": "0000-0003-4420-2838" }, { "family_name": "Enoto", "given_name": "Teruaki", "orcid": "0000-0003-1244-3100" }, { "family_name": "Evangelista", "given_name": "Yuri", "orcid": "0000-0001-6096-6710" }, { "family_name": "Fabiani", "given_name": "Sergio", "orcid": "0000-0003-1533-0283" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Gunji", "given_name": "Shuichi", "orcid": "0000-0002-5881-2445" }, { "family_name": "Hayashida", "given_name": "Kiyoshi" }, { "family_name": "Heyl", "given_name": "Jeremy", "orcid": "0000-0001-9739-367X" }, { "family_name": "Iwakiri", "given_name": "Wataru", "orcid": "0000-0002-0207-9010" }, { "family_name": "Jorstad", "given_name": "Svetlana G.", "orcid": "0000-0001-6158-1708" }, { "family_name": "Karas", "given_name": "Vladimir", "orcid": "0000-0002-5760-0459" }, { "family_name": "Kislat", "given_name": "Fabian", "orcid": "0000-0001-7477-0380" }, { "family_name": "Kitaguchi", "given_name": "Takao" }, { "family_name": "Kolodziejczak", "given_name": "Jeffery J.", "orcid": "0000-0002-0110-6136" }, { "family_name": "Krawczynski", "given_name": "Henric", "orcid": "0000-0002-1084-6507" }, { "family_name": "La Monaca", "given_name": "Fabio", "orcid": "0000-0001-8916-4156" }, { "family_name": "Latronico", "given_name": "Luca", "orcid": "0000-0002-0984-1856" }, { "family_name": "Liodakis", "given_name": "Ioannis", "orcid": "0000-0001-9200-4006" }, { "family_name": "Maldera", "given_name": "Simone", "orcid": "0000-0002-0698-4421" }, { "family_name": "Marin", "given_name": "Fr\u00e9d\u00e9ric", "orcid": "0000-0003-4952-0835" }, { "family_name": "Marinucci", "given_name": "Andrea", "orcid": "0000-0002-2055-4946" }, { "family_name": "Marscher", "given_name": "Alan P.", "orcid": "0000-0001-7396-3332" }, { "family_name": "Marshall", "given_name": "Herman L.", "orcid": "0000-0002-6492-1293" }, { "family_name": "Massaro", "given_name": "Francesco", "orcid": "0000-0002-1704-9850" }, { "family_name": "Matt", "given_name": "Giorgio", "orcid": "0000-0002-2152-0916" }, { "family_name": "Mitsuishi", "given_name": "Ikuyuki" }, { "family_name": "Mizuno", "given_name": "Tsunefumi", "orcid": "0000-0001-7263-0296" }, { "family_name": "Muleri", "given_name": "Fabio", "orcid": "0000-0003-3331-3794" }, { "family_name": "Ng", "given_name": "Chi-Yung", "orcid": "0000-0002-5847-2612" }, { "family_name": "O'Dell", "given_name": "Stephen L.", "orcid": "0000-0002-1868-8056" }, { "family_name": "Omodei", "given_name": "Nicola", "orcid": "0000-0002-5448-7577" }, { "family_name": "Oppedisano", "given_name": "Chiara", "orcid": "0000-0001-6194-4601" }, { "family_name": "Papitto", "given_name": "Alessandro", "orcid": "0000-0001-6289-7413" }, { "family_name": "Pavlov", "given_name": "George G.", "orcid": "0000-0002-7481-5259" }, { "family_name": "Peirson", "given_name": "Abel L.", "orcid": "0000-0001-6292-1911" }, { "family_name": "Perri", "given_name": "Matteo", "orcid": "0000-0003-3613-4409" }, { "family_name": "Pesce-Rollins", "given_name": "Melissa", "orcid": "0000-0003-1790-8018" }, { "family_name": "Petrucci", "given_name": "Pierre-Olivier", "orcid": "0000-0001-6061-3480" }, { "family_name": "Pilia", "given_name": "Maura", "orcid": "0000-0001-7397-8091" }, { "family_name": "Possenti", "given_name": "Andrea", "orcid": "0000-0001-5902-3731" }, { "family_name": "Puccetti", "given_name": "Simonetta", "orcid": "0000-0002-2734-7835" }, { "family_name": "Ramsey", "given_name": "Brian D.", "orcid": "0000-0003-1548-1524" }, { "family_name": "Rankin", "given_name": "John", "orcid": "0000-0002-9774-0560" }, { "family_name": "Roberts", "given_name": "Oliver J.", "orcid": "0000-0002-7150-9061" }, { "family_name": "Sgr\u00f2", "given_name": "Carmelo", "orcid": "0000-0001-5676-6214" }, { "family_name": "Spandre", "given_name": "Gloria", "orcid": "0000-0003-0802-3453" }, { "family_name": "Swartz", "given_name": "Douglas A.", "orcid": "0000-0002-2954-4461" }, { "family_name": "Tamagawa", "given_name": "Toru", "orcid": "0000-0002-8801-6263" }, { "family_name": "Tavecchio", "given_name": "Fabrizio", "orcid": "0000-0003-0256-0995" }, { "family_name": "Taverna", "given_name": "Roberto", "orcid": "0000-0002-1768-618X" }, { "family_name": "Tawara", "given_name": "Yuzuru" }, { "family_name": "Tennant", "given_name": "Allyn F.", "orcid": "0000-0002-9443-6774" }, { "family_name": "Thomas", "given_name": "Nicholas E.", "orcid": "0000-0003-0411-4606" }, { "family_name": "Tombesi", "given_name": "Francesco", "orcid": "0000-0002-6562-8654" }, { "family_name": "Trois", "given_name": "Alessio", "orcid": "0000-0002-3180-6002" }, { "family_name": "Tsygankov", "given_name": "Sergey S.", "orcid": "0000-0002-9679-0793" }, { "family_name": "Turolla", "given_name": "Roberto", "orcid": "0000-0003-3977-8760" }, { "family_name": "Vink", "given_name": "Jacco", "orcid": "0000-0002-4708-4219" }, { "family_name": "Weisskopf", "given_name": "Martin C.", "orcid": "0000-0002-5270-4240" }, { "family_name": "Xie", "given_name": "Fei", "orcid": "0000-0002-0105-5826" }, { "family_name": "Zane", "given_name": "Silvia", "orcid": "0000-0001-5326-880X" } ], "abstract": "
\n

How astrophysical systems translate the kinetic energy of bulk motion into the acceleration of particles to very high energies is a pressing question. SS 433 is a microquasar that emits TeV γ-rays indicating the presence of high-energy particles. A region of hard X-ray emission in the eastern lobe of SS 433 was recently identified as an acceleration site. We observed this region with the Imaging X-ray Polarimetry Explorer and measured a polarization degree in the range 38%–77%. The high polarization degree indicates the magnetic field has a well-ordered component if the X-rays are due to synchrotron emission. The polarization angle is in the range −12° to +10° (east of north), which indicates that the magnetic field is parallel to the jet. Magnetic fields parallel to the bulk flow have also been found in supernova remnants and the jets of powerful radio galaxies. This may be caused by interaction of the flow with the ambient medium.

\n
", "doi": "10.3847/2041-8213/ad103b", "issn": "2041-8205", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal Letters", "publication_date": "2024-01-20", "series_number": "1", "volume": "961", "issue": "1", "pages": "L12" }, { "id": "authors:adtc3-xv586", "collection": "authors", "collection_id": "adtc3-xv586", "cite_using_url": "https://authors.library.caltech.edu/records/adtc3-xv586", "type": "article", "title": "The high energy X-ray probe (HEX-P): sensitive broadband X-ray observations of transient phenomena in the 2030s", "author": [ { "family_name": "Brightman", "given_name": "Murray", "orcid": "0000-0002-8147-2602", "clpid": "Brightman-Murray" }, { "family_name": "Margutti", "given_name": "Raffaella", "orcid": "0000-0003-4768-7586" }, { "family_name": "Polzin", "given_name": "Ava", "orcid": "0000-0002-5283-933X" }, { "family_name": "Jaodand", "given_name": "Amruta", "orcid": "0000-0002-3850-6651", "clpid": "Jaodand-Amruta" }, { "family_name": "Hotokezaka", "given_name": "Kenta", "orcid": "0000-0001-5023-6933" }, { "family_name": "Alford", "given_name": "Jason A. J." }, { "family_name": "Hallinan", "given_name": "Gregg", "orcid": "0000-0002-7083-4049", "clpid": "Hallinan-G" }, { "family_name": "Kammoun", "given_name": "Elias", "orcid": "0000-0002-0273-218X" }, { "family_name": "Mooley", "given_name": "Kunal", "orcid": "0000-0002-2557-5180", "clpid": "Mooley-Kunal-Prakash" }, { "family_name": "Masterson", "given_name": "Megan", "orcid": "0000-0003-4127-0739" }, { "family_name": "Marcotulli", "given_name": "Lea", "orcid": "0000-0002-8472-3649" }, { "family_name": "Rau", "given_name": "Arne", "orcid": "0000-0001-5990-6243" }, { "family_name": "Wevers", "given_name": "Thomas", "orcid": "0000-0002-4043-9400" }, { "family_name": "Younes", "given_name": "George A.", "orcid": "0000-0002-7991-028X" }, { "family_name": "Stern", "given_name": "Daniel", "orcid": "0000-0003-2686-9241", "clpid": "Stern-D" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Madsen", "given_name": "Kristin", "orcid": "0000-0003-1252-4891" } ], "abstract": "

HEX-P is a probe-class mission concept that will combine high spatial resolution X-ray imaging (<10′′ FWHM) and broad spectral coverage (0.2–80 keV) with an effective area superior to NuSTAR above 10 keV to enable revolutionary new insights into a variety of astrophysical problems, especially those related to compact objects, accretion and outflows. HEX-P will launch at a time when the sky is being routinely scanned for transient gravitational wave, electromagnetic and neutrino phenomena that will require the capabilities of a sensitive, broadband X-ray telescope for follow up studies. These include the merger of compact objects such as neutron stars and black holes, stellar explosions, and the birth of new compact objects. A response time to target of opportunity observation requests of <24 hours and a field of regard of 3π steradians will allow HEX-P to probe the accretion and ejecta from these transient phenomena through the study of relativistic outflows and reprocessed emission, provide unique capabilities for understanding jet physics, and potentially revealing the nature of the central engine.

", "doi": "10.3389/fspas.2023.1292656", "issn": "2296-987X", "publisher": "Frontiers Media SA", "publication": "Frontiers in Astronomy and Space Sciences", "publication_date": "2024-01-09", "volume": "10", "pages": "1292656" }, { "id": "authors:jntd1-93p75", "collection": "authors", "collection_id": "jntd1-93p75", "cite_using_url": "https://authors.library.caltech.edu/records/jntd1-93p75", "type": "article", "title": "First X-Ray Polarization Measurement Confirms the Low Black Hole Spin in LMC X-3", "author": [ { "family_name": "Svoboda", "given_name": "Ji\u0159\u00ed", "orcid": "0000-0003-2931-0742", "clpid": "Svoboda-Ji\u0159\u00ed" }, { "family_name": "Dov\u010diak", "given_name": "Michal", "orcid": "0000-0003-0079-1239" }, { "family_name": "Steiner", "given_name": "James F.", "orcid": "0000-0002-5872-6061" }, { "family_name": "Muleri", "given_name": "Fabio", "orcid": "0000-0003-3331-3794" }, { "family_name": "Ingram", "given_name": "Adam", "orcid": "0000-0002-5311-9078" }, { "family_name": "Yilmaz", "given_name": "Anastasiya", "orcid": "0000-0003-1133-1684" }, { "family_name": "Rodriguez Cavero", "given_name": "Nicole", "orcid": "0000-0001-5256-0278" }, { "family_name": "Marra", "given_name": "Lorenzo", "orcid": "0009-0001-4644-194X" }, { "family_name": "Poutanen", "given_name": "Juri", "orcid": "0000-0002-0983-0049" }, { "family_name": "Veledina", "given_name": "Alexandra", "orcid": "0000-0002-5767-7253" }, { "family_name": "Mojaver", "given_name": "Mehrnoosh Rahbardar", "orcid": "0000-0002-9633-0359" }, { "family_name": "Bianchi", "given_name": "Stefano", "orcid": "0000-0002-4622-4240" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Kaaret", "given_name": "Philip", "orcid": "0000-0002-3638-0637" }, { "family_name": "Krawczynski", "given_name": "Henric", "orcid": "0000-0002-1084-6507" }, { "family_name": "Matt", "given_name": "Giorgio", "orcid": "0000-0002-2152-0916" }, { "family_name": "Podgorn\u00fd", "given_name": "Jakub", "orcid": "0000-0001-5418-291X" }, { "family_name": "Weisskopf", "given_name": "Martin C.", "orcid": "0000-0002-5270-4240" }, { "family_name": "Kislat", "given_name": "Fabian", "orcid": "0000-0001-7477-0380" }, { "family_name": "Petrucci", "given_name": "Pierre-Olivier", "orcid": "0000-0001-6061-3480" }, { "family_name": "Brigitte", "given_name": "Maimouna", "orcid": "0009-0004-1197-5935" }, { "family_name": "Bursa", "given_name": "Michal", "orcid": "0000-0003-0167-1888" }, { "family_name": "Fabiani", "given_name": "Sergio", "orcid": "0000-0003-1533-0283" }, { "family_name": "Hu", "given_name": "Kun", "orcid": "0000-0002-9705-7948" }, { "family_name": "Chun", "given_name": "Sohee", "orcid": "0009-0002-2488-5272" }, { "family_name": "Mastroserio", "given_name": "Guglielmo", "orcid": "0000-0003-4216-7936" }, { "family_name": "Mikus\u0306incov\u00e1", "given_name": "Romana", "orcid": "0000-0001-7374-843X" }, { "family_name": "Ratheesh", "given_name": "Ajay", "orcid": "0000-0003-0411-4243" }, { "family_name": "Romani", "given_name": "Roger W.", "orcid": "0000-0001-6711-3286" }, { "family_name": "Soffitta", "given_name": "Paolo", "orcid": "0000-0002-7781-4104" }, { "family_name": "Ursini", "given_name": "Francesco", "orcid": "0000-0001-9442-7897" }, { "family_name": "Zane", "given_name": "Silvia", "orcid": "0000-0001-5326-880X" }, { "family_name": "Agudo", "given_name": "Iv\u00e1n", "orcid": "0000-0002-3777-6182" }, { "family_name": "Antonelli", "given_name": "Lucio A.", "orcid": "0000-0002-5037-9034" }, { "family_name": "Bachetti", "given_name": "Matteo", "orcid": "0000-0002-4576-9337" }, { "family_name": "Baldini", "given_name": "Luca", "orcid": "0000-0002-9785-7726" }, { "family_name": "Baumgartner", "given_name": "Wayne H.", "orcid": "0000-0002-5106-0463" }, { "family_name": "Bellazzini", "given_name": "Ronaldo", "orcid": "0000-0002-2469-7063" }, { "family_name": "Bongiorno", "given_name": "Stephen D.", "orcid": "0000-0002-0901-2097" }, { "family_name": "Bonino", "given_name": "Raffaella", "orcid": "0000-0002-4264-1215" }, { "family_name": "Brez", "given_name": "Alessandro", "orcid": "0000-0002-9460-1821" }, { "family_name": "Bucciantini", "given_name": "Niccol\u00f2", "orcid": "0000-0002-8848-1392" }, { "family_name": "Capitanio", "given_name": "Fiamma", "orcid": "0000-0002-6384-3027" }, { "family_name": "Castellano", "given_name": "Simone", "orcid": "0000-0003-1111-4292" }, { "family_name": "Cavazzuti", "given_name": "Elisabetta", "orcid": "0000-0001-7150-9638" }, { "family_name": "Chen", "given_name": "Chien-Ting", "orcid": "0000-0002-4945-5079" }, { "family_name": "Ciprini", "given_name": "Stefano", "orcid": "0000-0002-0712-2479" }, { "family_name": "Costa", "given_name": "Enrico", "orcid": "0000-0003-4925-8523" }, { "family_name": "De Rosa", "given_name": "Alessandra", "orcid": "0000-0001-5668-6863" }, { "family_name": "Del Monte", "given_name": "Ettore", "orcid": "0000-0002-3013-6334" }, { "family_name": "Di Gesu", "given_name": "Laura", "orcid": "0000-0002-5614-5028" }, { "family_name": "Di Lalla", "given_name": "Niccol\u00f2", "orcid": "0000-0002-7574-1298" }, { "family_name": "Di Marco", "given_name": "Alessandro", "orcid": "0000-0003-0331-3259" }, { "family_name": "Donnarumma", "given_name": "Immacolata", "orcid": "0000-0002-4700-4549" }, { "family_name": "Doroshenko", "given_name": "Victor", "orcid": "0000-0001-8162-1105" }, { "family_name": "Ehlert", "given_name": "Steven R.", "orcid": "0000-0003-4420-2838" }, { "family_name": "Enoto", "given_name": "Teruaki", "orcid": "0000-0003-1244-3100" }, { "family_name": "Evangelista", "given_name": "Yuri", "orcid": "0000-0001-6096-6710" }, { "family_name": "Ferrazzoli", "given_name": "Riccardo", "orcid": "0000-0003-1074-8605" }, { "family_name": "Gunji", "given_name": "Shuichi", "orcid": "0000-0002-5881-2445" }, { "family_name": "Hayashida", "given_name": "Kiyoshi" }, { "family_name": "Heyl", "given_name": "Jeremy", "orcid": "0000-0001-9739-367X" }, { "family_name": "Iwakiri", "given_name": "Wataru", "orcid": "0000-0002-0207-9010" }, { "family_name": "Jorstad", "given_name": "Svetlana G.", "orcid": "0000-0001-6158-1708" }, { "family_name": "Karas", "given_name": "Vladim\u00edr", "orcid": "0000-0002-5760-0459" }, { "family_name": "Kitaguchi", "given_name": "Takao" }, { "family_name": "Kolodziejczak", "given_name": "Jeffery J.", "orcid": "0000-0002-0110-6136" }, { "family_name": "La Monaca", "given_name": "Fabio", "orcid": "0000-0001-8916-4156" }, { "family_name": "Latronico", "given_name": "Luca", "orcid": "0000-0002-0984-1856" }, { "family_name": "Liodakis", "given_name": "Ioannis", "orcid": "0000-0001-9200-4006" }, { "family_name": "Maldera", "given_name": "Simone", "orcid": "0000-0002-0698-4421" }, { "family_name": "Manfreda", "given_name": "Alberto", "orcid": "0000-0002-0998-4953" }, { "family_name": "Marin", "given_name": "Fr\u00e9d\u00e9ric", "orcid": "0000-0003-4952-0835" }, { "family_name": "Marinucci", "given_name": "Andrea", "orcid": "0000-0002-2055-4946" }, { "family_name": "Marscher", "given_name": "Alan P.", "orcid": "0000-0001-7396-3332" }, { "family_name": "Marshall", "given_name": "Herman L.", "orcid": "0000-0002-6492-1293" }, { "family_name": "Massaro", "given_name": "Francesco", "orcid": "0000-0002-1704-9850" }, { "family_name": "Mitsuishi", "given_name": "Ikuyuki", "orcid": "0000-0002-9901-233X" }, { "family_name": "Mizuno", "given_name": "Tsunefumi", "orcid": "0000-0001-7263-0296" }, { "family_name": "Negro", "given_name": "Michela", "orcid": "0000-0002-6548-5622" }, { "family_name": "Ng", "given_name": "Chi-Yung", "orcid": "0000-0002-5847-2612" }, { "family_name": "O'Dell", "given_name": "Stephen L.", "orcid": "0000-0002-1868-8056" }, { "family_name": "Omodei", "given_name": "Nicola", "orcid": "0000-0002-5448-7577" }, { "family_name": "Oppedisano", "given_name": "Chiara", "orcid": "0000-0001-6194-4601" }, { "family_name": "Papitto", "given_name": "Alessandro", "orcid": "0000-0001-6289-7413" }, { "family_name": "Pavlov", "given_name": "George G.", "orcid": "0000-0002-7481-5259" }, { "family_name": "Peirson", "given_name": "Abel L.", "orcid": "0000-0001-6292-1911" }, { "family_name": "Perri", "given_name": "Matteo", "orcid": "0000-0003-3613-4409" }, { "family_name": "Pesce-Rollins", "given_name": "Melissa", "orcid": "0000-0003-1790-8018" }, { "family_name": "Pilia", "given_name": "Maura", "orcid": "0000-0001-7397-8091" }, { "family_name": "Possenti", "given_name": "Andrea", "orcid": "0000-0001-5902-3731" }, { "family_name": "Puccetti", "given_name": "Simonetta", "orcid": "0000-0002-2734-7835" }, { "family_name": "Ramsey", "given_name": "Brian D.", "orcid": "0000-0003-1548-1524" }, { "family_name": "Rankin", "given_name": "John", "orcid": "0000-0002-9774-0560" }, { "family_name": "Roberts", "given_name": "Oliver J.", "orcid": "0000-0002-7150-9061" }, { "family_name": "Sgr\u00f2", "given_name": "Carmelo", "orcid": "0000-0001-5676-6214" }, { "family_name": "Slane", "given_name": "Patrick", "orcid": "0000-0002-6986-6756" }, { "family_name": "Spandre", "given_name": "Gloria", "orcid": "0000-0003-0802-3453" }, { "family_name": "Swartz", "given_name": "Douglas A.", "orcid": "0000-0002-2954-4461" }, { "family_name": "Tamagawa", "given_name": "Toru", "orcid": "0000-0002-8801-6263" }, { "family_name": "Tavecchio", "given_name": "Fabrizio", "orcid": "0000-0003-0256-0995" }, { "family_name": "Taverna", "given_name": "Roberto", "orcid": "0000-0002-1768-618X" }, { "family_name": "Tawara", "given_name": "Yuzuru" }, { "family_name": "Tennant", "given_name": "Allyn F.", "orcid": "0000-0002-9443-6774" }, { "family_name": "Thomas", "given_name": "Nicholas E.", "orcid": "0000-0003-0411-4606" }, { "family_name": "Tombesi", "given_name": "Francesco", "orcid": "0000-0002-6562-8654" }, { "family_name": "Trois", "given_name": "Alessio", "orcid": "0000-0002-3180-6002" }, { "family_name": "Tsygankov", "given_name": "Sergey S.", "orcid": "0000-0002-9679-0793" }, { "family_name": "Turolla", "given_name": "Roberto", "orcid": "0000-0003-3977-8760" }, { "family_name": "Vink", "given_name": "Jacco", "orcid": "0000-0002-4708-4219" }, { "family_name": "Wu", "given_name": "Kinwah", "orcid": "0000-0002-7568-8765" }, { "family_name": "Xie", "given_name": "Fei", "orcid": "0000-0002-0105-5826" } ], "abstract": "
\n

X-ray polarization is a powerful tool to investigate the geometry of accreting material around black holes, allowing independent measurements of the black hole spin and orientation of the innermost parts of the accretion disk. We perform X-ray spectropolarimetric analysis of an X-ray binary system in the Large Magellanic Cloud, LMC X-3, that hosts a stellar-mass black hole, known to be persistently accreting since its discovery. We report the first detection of the X-ray polarization in LMC X-3 with the Imaging X-ray Polarimetry Explorer, and find the average polarization degree (PD) of 3.2% ± 0.6% and a constant polarization angle of −42° ± 6° over the 2–8 keV range. Using accompanying spectroscopic observations by NICER, NuSTAR, and the Neil Gehrels Swift observatories, we confirm previous measurements of the black hole spin via the X-ray continuum method, a ≈ 0.2. From polarization analysis only, we found consistent results with low black hole spin, with an upper limit of a < 0.7 at a 90% confidence level. A slight increase in the PD with energy, similar to other black hole X-ray binaries in the soft state, is suggested from the data but with a low statistical significance.

\n
", "doi": "10.3847/1538-4357/ad0842", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2024-01-01", "series_number": "1", "volume": "960", "issue": "1", "pages": "3" }, { "id": "authors:8mxmz-geg57", "collection": "authors", "collection_id": "8mxmz-geg57", "cite_using_url": "https://authors.library.caltech.edu/records/8mxmz-geg57", "type": "article", "title": "Sulphur X-ray absorption in the local ISM", "author": [ { "family_name": "Gatuzz", "given_name": "Efrain", "orcid": "0000-0002-3252-9633" }, { "family_name": "Gorczyca", "given_name": "T W", "orcid": "0000-0003-4117-5790" }, { "family_name": "Hasoglu", "given_name": "M F", "orcid": "0000-0001-6735-9438" }, { "family_name": "Costantini", "given_name": "E", "orcid": "0000-0001-8470-749X" }, { "family_name": "Garc\u00eda", "given_name": "Javier A", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Kallman", "given_name": "Timothy R", "orcid": "0000-0002-5779-6906" } ], "abstract": "

We present a study S K-edge using high-resolution HETGS Chandra spectra of 36 low-mass X-ray binaries. For each source, we have estimated column densities for S i, S ii, S iii, S xiv, S xv, and S xvi ionic species, which trace the neutral, warm, and hot phases of the Galactic interstellar medium. We also estimated column densities for a sample of interstellar dust analogues. We measured their distribution as a function of Galactic latitude, longitude, and distances to the sources. While the cold-warm column densities tend to decrease with the Galactic latitude, we found no correlation with distances or Galactic longitude. This is the first detailed analysis of the sulphur K-edge absorption due to ISM using high-resolution X-ray spectra.

", "doi": "10.1093/mnras/stad3231", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2024-01", "series_number": "2", "volume": "527", "issue": "2", "pages": "1648-1655" }, { "id": "authors:78xzp-4sc70", "collection": "authors", "collection_id": "78xzp-4sc70", "cite_using_url": "https://authors.library.caltech.edu/records/78xzp-4sc70", "type": "article", "title": "Variability as a Predictor for the Hard-to-soft State Transition in GX 339\u22124", "author": [ { "family_name": "Lucchini", "given_name": "Matteo", "orcid": "0000-0002-2235-3347" }, { "family_name": "Ten Have", "given_name": "Marina" }, { "family_name": "Wang", "given_name": "Jingyi", "orcid": "0000-0002-1742-2125" }, { "family_name": "Homan", "given_name": "Jeroen", "orcid": "0000-0001-8371-2713" }, { "family_name": "Kara", "given_name": "Erin", "orcid": "0000-0003-0172-0854" }, { "family_name": "Adegoke", "given_name": "Oluwashina", "orcid": "0000-0002-5966-4210", "clpid": "Adegoke-Oluwashina" }, { "family_name": "Connors", "given_name": "Riley", "orcid": "0000-0002-8908-759X" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048" }, { "family_name": "Garcia", "given_name": "Javier", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Mastroserio", "given_name": "Guglielmo", "orcid": "0000-0003-4216-7936" }, { "family_name": "Ingram", "given_name": "Adam", "orcid": "0000-0002-5311-9078" }, { "family_name": "van der Klis", "given_name": "Michiel", "orcid": "0000-0003-0070-9872" }, { "family_name": "K\u00f6nig", "given_name": "Ole", "orcid": "0000-0001-8670-4575" }, { "family_name": "Lewin", "given_name": "Collin", "orcid": "0000-0002-8671-1190" }, { "family_name": "Mallick", "given_name": "Labani", "orcid": "0000-0001-8624-9162", "clpid": "Mallick-Labani" }, { "family_name": "Nathan", "given_name": "Edward", "orcid": "0000-0002-9633-9193", "clpid": "Nathan-Edward" }, { "family_name": "O'Neill", "given_name": "Patrick" }, { "family_name": "Panagiotou", "given_name": "Christos" }, { "family_name": "Piotrowska", "given_name": "Joanna", "orcid": "0000-0003-1661-2338", "clpid": "Piotrowska-Joanna-M" }, { "family_name": "Uttley", "given_name": "Phil", "orcid": "0000-0001-9355-961X" } ], "abstract": "

During the outbursts of black hole X-ray binaries (BHXRBs), their accretion flows transition through several states. The source luminosity rises in the hard state, dominated by nonthermal emission, before transitioning to the blackbody-dominated soft state. As the luminosity decreases, the source transitions back into the hard state and fades to quiescence. This picture does not always hold, as ≈40% of the outbursts never leave the hard state. Identifying the physics that govern state transitions remains one of the outstanding open questions in black hole astrophysics. In this paper we present an analysis of archival RXTE data of multiple outbursts of GX 339−4. We compare the properties of the X-ray variability and time-averaged energy spectrum and demonstrate that the variability (quantified by the power spectral hue) systematically evolves ≈10–40 days ahead of the canonical state transition (quantified by a change in spectral hardness); no such evolution is found in hard-state-only outbursts. This indicates that the X-ray variability can be used to predict if and when the hard-to-soft state transition will occur. Finally, we find a similar behavior in 10 outbursts of four additional BHXRBs with more sparse observational coverage. Based on these findings, we suggest that state transitions in BHXRBs might be driven by a change in the turbulence in the outer regions of the disk, leading to a dramatic change in variability. This change is only seen in the spectrum days to weeks later, as the fluctuations propagate inwards toward the corona.

", "doi": "10.3847/1538-4357/ad0294", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2023-12-01", "series_number": "2", "volume": "958", "issue": "2", "pages": "153" }, { "id": "authors:ejj37-frq33", "collection": "authors", "collection_id": "ejj37-frq33", "cite_using_url": "https://authors.library.caltech.edu/records/ejj37-frq33", "type": "article", "title": "The first X-ray polarimetric observation of the black hole binary LMC\u00a0X-1", "author": [ { "family_name": "Podgorn\u00fd", "given_name": "J.", "orcid": "0000-0001-5418-291X", "clpid": "Podgorn\u00fd-Jakub" }, { "family_name": "Marra", "given_name": "L." }, { "family_name": "Muleri", "given_name": "F.", "orcid": "0000-0003-3331-3794" }, { "family_name": "Rodriguez\u00a0Cavero", "given_name": "N.", "orcid": "0000-0001-5256-0278" }, { "family_name": "Ratheesh", "given_name": "A.", "orcid": "0000-0003-0411-4243" }, { "family_name": "Dov\u010diak", "given_name": "M.", "orcid": "0000-0003-0079-1239" }, { "family_name": "Miku\u0161incov\u00e1", "given_name": "R.", "orcid": "0000-0001-7374-843X" }, { "family_name": "Brigitte", "given_name": "M." }, { "family_name": "Steiner", "given_name": "J. F." }, { "family_name": "Veledina", "given_name": "A.", "orcid": "0000-0002-5767-7253" }, { "family_name": "Bianchi", "given_name": "S." }, { "family_name": "Krawczynski", "given_name": "H.", "orcid": "0000-0002-1084-6507" }, { "family_name": "Svoboda", "given_name": "J." }, { "family_name": "Kaaret", "given_name": "P.", "orcid": "0000-0002-3638-0637" }, { "family_name": "Matt", "given_name": "G." }, { "family_name": "Garcia", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Petrucci", "given_name": "P.-O." }, { "family_name": "Lutovinov", "given_name": "A.", "orcid": "0000-0002-6255-9972" }, { "family_name": "Semena", "given_name": "A." }, { "family_name": "Di\u00a0Marco", "given_name": "A.", "orcid": "0000-0003-0331-3259" }, { "family_name": "Negro", "given_name": "M.", "orcid": "0000-0002-6548-5622" }, { "family_name": "Weisskopf", "given_name": "M. C." }, { "family_name": "Ingram", "given_name": "A.", "orcid": "0000-0002-5311-9078" }, { "family_name": "Poutanen", "given_name": "J.", "orcid": "0000-0002-0983-0049" }, { "family_name": "Beheshtipour", "given_name": "B.", "orcid": "0000-0002-8524-1537" }, { "family_name": "Chun", "given_name": "S." }, { "family_name": "Hu", "given_name": "K." }, { "family_name": "Mizuno", "given_name": "T." }, { "family_name": "Sixuan", "given_name": "Z." }, { "family_name": "Tombesi", "given_name": "F.", "orcid": "0000-0002-6562-8654" }, { "family_name": "Zane", "given_name": "S." }, { "family_name": "Agudo", "given_name": "I.", "orcid": "0000-0002-3777-6182" }, { "family_name": "Antonelli", "given_name": "L. A." }, { "family_name": "Bachetti", "given_name": "M.", "orcid": "0000-0002-4576-9337" }, { "family_name": "Baldini", "given_name": "L.", "orcid": "0000-0002-9785-7726" }, { "family_name": "Baumgartner", "given_name": "W. H." }, { "family_name": "Bellazzini", "given_name": "R.", "orcid": "0000-0002-2469-7063" }, { "family_name": "Bongiorno", "given_name": "S. D." }, { "family_name": "Bonino", "given_name": "R.", "orcid": "0000-0002-4264-1215" }, { "family_name": "Brez", "given_name": "A.", "orcid": "0000-0002-9460-1821" }, { "family_name": "Bucciantini", "given_name": "N.", "orcid": "0000-0002-8848-1392" }, { "family_name": "Capitanio", "given_name": "F.", "orcid": "0000-0002-6384-3027" }, { "family_name": "Castellano", "given_name": "S." }, { "family_name": "Cavazzuti", "given_name": "E.", "orcid": "0000-0001-7150-9638" }, { "family_name": "Chen", "given_name": "C." }, { "family_name": "Ciprini", "given_name": "S.", "orcid": "0000-0002-0712-2479" }, { "family_name": "Costa", "given_name": "E." }, { "family_name": "De\u00a0Rosa", "given_name": "A." }, { "family_name": "Del\u00a0Monte", "given_name": "E.", "orcid": "0000-0002-3013-6334" }, { "family_name": "Di\u00a0Gesu", "given_name": "L.", "orcid": "0000-0002-5614-5028" }, { "family_name": "Di\u00a0Lalla", "given_name": "N." }, { "family_name": "Donnarumma", "given_name": "I." }, { "family_name": "Doroshenko", "given_name": "V.", "orcid": "0000-0001-8162-1105" }, { "family_name": "Ehlert", "given_name": "S. R.", "orcid": "0000-0003-4420-2838" }, { "family_name": "Enoto", "given_name": "T." }, { "family_name": "Evangelista", "given_name": "Y." }, { "family_name": "Fabiani", "given_name": "S." }, { "family_name": "Ferrazzoli", "given_name": "R.", "orcid": "0000-0003-1074-8605" }, { "family_name": "Gunji", "given_name": "S.", "orcid": "0000-0002-5881-2445" }, { "family_name": "Hayashida", "given_name": "K." }, { "family_name": "Heyl", "given_name": "J.", "orcid": "0000-0001-9739-367X" }, { "family_name": "Iwakiri", "given_name": "W.", "orcid": "0000-0002-0207-9010" }, { "family_name": "Jorstad", "given_name": "S. G.", "orcid": "0000-0001-6158-1708" }, { "family_name": "Karas", "given_name": "V." }, { "family_name": "Kislat", "given_name": "F.", "orcid": "0000-0001-7477-0380" }, { "family_name": "Kitaguchi", "given_name": "T." }, { "family_name": "Kolodziejczak", "given_name": "J. J.", "orcid": "0000-0002-0110-6136" }, { "family_name": "La\u00a0Monaca", "given_name": "F.", "orcid": "0000-0001-8916-4156" }, { "family_name": "Latronico", "given_name": "L.", "orcid": "0000-0002-0984-1856" }, { "family_name": "Liodakis", "given_name": "I.", "orcid": "0000-0001-9200-4006" }, { "family_name": "Maldera", "given_name": "S.", "orcid": "0000-0002-0698-4421" }, { "family_name": "Manfreda", "given_name": "A.", "orcid": "0000-0002-0998-4953" }, { "family_name": "Marin", "given_name": "F." }, { "family_name": "Marinucci", "given_name": "A." }, { "family_name": "Marscher", "given_name": "A. P.", "orcid": "0000-0001-7396-3332" }, { "family_name": "Marshall", "given_name": "H. L." }, { "family_name": "Massaro", "given_name": "F.", "orcid": "0000-0002-1704-9850" }, { "family_name": "Mitsuishi", "given_name": "I.", "orcid": "0000-0002-9901-233X" }, { "family_name": "Ng", "given_name": "C.-Y." }, { "family_name": "O'Dell", "given_name": "S. L." }, { "family_name": "Omodei", "given_name": "N.", "orcid": "0000-0002-5448-7577" }, { "family_name": "Oppedisano", "given_name": "C.", "orcid": "0000-0001-6194-4601" }, { "family_name": "Papitto", "given_name": "A.", "orcid": "0000-0001-6289-7413" }, { "family_name": "Pavlov", "given_name": "G. G." }, { "family_name": "Peirson", "given_name": "A. L.", "orcid": "0000-0001-6292-1911" }, { "family_name": "Perri", "given_name": "M.", "orcid": "0000-0003-3613-4409" }, { "family_name": "Pesce-Rollins", "given_name": "M.", "orcid": "0000-0003-1790-8018" }, { "family_name": "Pilia", "given_name": "M.", "orcid": "0000-0001-7397-8091" }, { "family_name": "Possenti", "given_name": "A.", "orcid": "0000-0001-5902-3731" }, { "family_name": "Puccetti", "given_name": "S.", "orcid": "0000-0002-2734-7835" }, { "family_name": "Ramsey", "given_name": "B. D." }, { "family_name": "Rankin", "given_name": "J." }, { "family_name": "Roberts", "given_name": "O. J.", "orcid": "0000-0002-7150-9061" }, { "family_name": "Romani", "given_name": "R. W." }, { "family_name": "Sgr\u00f2", "given_name": "C." }, { "family_name": "Slane", "given_name": "P.", "orcid": "0000-0002-6986-6756" }, { "family_name": "Soffitta", "given_name": "P.", "orcid": "0000-0002-7781-4104" }, { "family_name": "Spandre", "given_name": "G.", "orcid": "0000-0003-0802-3453" }, { "family_name": "Swartz", "given_name": "D. A." }, { "family_name": "Tamagawa", "given_name": "T." }, { "family_name": "Tavecchio", "given_name": "F.", "orcid": "0000-0003-0256-0995" }, { "family_name": "Taverna", "given_name": "R." }, { "family_name": "Tawara", "given_name": "Y." }, { "family_name": "Tennant", "given_name": "A. F." }, { "family_name": "Thomas", "given_name": "N. E." }, { "family_name": "Trois", "given_name": "A.", "orcid": "0000-0002-3180-6002" }, { "family_name": "Tsygankov", "given_name": "S. S." }, { "family_name": "Turolla", "given_name": "R.", "orcid": "0000-0002-5825-8149" }, { "family_name": "Vink", "given_name": "J.", "orcid": "0000-0002-4708-4219" }, { "family_name": "Wu", "given_name": "K." }, { "family_name": "Xie", "given_name": "F." } ], "abstract": "

We report on an X-ray polarimetric observation of the high-mass X-ray binary LMC X-1 in the high/soft state, obtained by the Imaging X-ray Polarimetry Explorer (IXPE) in 2022 October. The measured polarization is below the minimum detectable polarization of 1.1 per cent (at the 99 per cent confidence level). Simultaneously, the source was observed with the Neutron Star Interior Composition Explorer (NICER), Nuclear Spectroscopic Telescope Array (NuSTAR), and Spectrum-Rontgen-Gamma (SRG)/Astronomical Roentgen Telescope – X-ray Concentrator (ART-XC) instruments, which enabled spectral decomposition into a dominant thermal component and a Comptonized one. The low 2–8 keV polarization of the source did not allow for strong constraints on the black hole spin and inclination of the accretion disc. However, if the orbital inclination of about 36° is assumed, then the upper limit is consistent with predictions for pure thermal emission from geometrically thin and optically thick discs. Assuming the polarization degree of the Comptonization component to be 0, 4, or 10 per cent, and oriented perpendicular to the polarization of the disc emission (in turn assumed to be perpendicular to the large-scale ionization cone orientation detected in the optical band), an upper limit to the polarization of the disc emission of 1.0, 0.9, or 0.9 per cent, respectively, is found (at the 99 per cent confidence level).

", "doi": "10.1093/mnras/stad3103", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2023-12", "series_number": "4", "volume": "526", "issue": "4", "pages": "5964-5975" }, { "id": "authors:q5w8w-xz917", "collection": "authors", "collection_id": "q5w8w-xz917", "cite_using_url": "https://authors.library.caltech.edu/records/q5w8w-xz917", "type": "article", "title": "The First X-Ray Polarization Observation of the Black Hole X-Ray Binary 4U 1630\u201347 in the Steep Power-law State", "author": [ { "family_name": "Rodriguez Cavero", "given_name": "Nicole", "orcid": "0000-0001-5256-0278" }, { "family_name": "Marra", "given_name": "Lorenzo", "orcid": "0009-0001-4644-194X" }, { "family_name": "Krawczynski", "given_name": "Henric", "orcid": "0000-0002-1084-6507" }, { "family_name": "Dov\u010diak", "given_name": "Michal", "orcid": "0000-0003-0079-1239" }, { "family_name": "Bianchi", "given_name": "Stefano", "orcid": "0000-0002-4622-4240" }, { "family_name": "Steiner", "given_name": "James F.", "orcid": "0000-0002-5872-6061" }, { "family_name": "Svoboda", "given_name": "Jiri", "orcid": "0000-0003-2931-0742" }, { "family_name": "Capitanio", "given_name": "Fiamma", "orcid": "0000-0002-6384-3027" }, { "family_name": "Matt", "given_name": "Giorgio", "orcid": "0000-0002-2152-0916" }, { "family_name": "Negro", "given_name": "Michela", "orcid": "0000-0002-6548-5622" }, { "family_name": "Ingram", "given_name": "Adam", "orcid": "0000-0002-5311-9078" }, { "family_name": "Veledina", "given_name": "Alexandra", "orcid": "0000-0002-5767-7253" }, { "family_name": "Taverna", "given_name": "Roberto", "orcid": "0000-0002-1768-618X" }, { "family_name": "Karas", "given_name": "Vladimir", "orcid": "0000-0002-5760-0459" }, { "family_name": "Ursini", "given_name": "Francesco", "orcid": "0000-0001-9442-7897" }, { "family_name": "Podgorn\u00fd", "given_name": "Jakub", "orcid": "0000-0001-5418-291X" }, { "family_name": "Ratheesh", "given_name": "Ajay", "orcid": "0000-0003-0411-4243" }, { "family_name": "Suleimanov", "given_name": "Valery", "orcid": "0000-0003-3733-7267" }, { "family_name": "Miku\u0161incov\u00e1", "given_name": "Romana", "orcid": "0000-0001-7374-843X" }, { "family_name": "Zane", "given_name": "Silvia", "orcid": "0000-0001-5326-880X" }, { "family_name": "Kaaret", "given_name": "Philip", "orcid": "0000-0002-3638-0637" }, { "family_name": "Muleri", "given_name": "Fabio", "orcid": "0000-0003-3331-3794" }, { "family_name": "Poutanen", "given_name": "Juri", "orcid": "0000-0002-0983-0049" }, { "family_name": "Malacaria", "given_name": "Christian", "orcid": "0000-0002-0380-0041" }, { "family_name": "Petrucci", "given_name": "Pierre-Olivier", "orcid": "0000-0001-6061-3480" }, { "family_name": "Gau", "given_name": "Ephraim", "orcid": "0000-0002-5250-2710" }, { "family_name": "Hu", "given_name": "Kun", "orcid": "0000-0002-9705-7948" }, { "family_name": "Chun", "given_name": "Sohee", "orcid": "0009-0002-2488-5272" }, { "family_name": "Agudo", "given_name": "Iv\u00e1n", "orcid": "0000-0002-3777-6182" }, { "family_name": "Antonelli", "given_name": "Lucio A.", "orcid": "0000-0002-5037-9034" }, { "family_name": "Bachetti", "given_name": "Matteo", "orcid": "0000-0002-4576-9337" }, { "family_name": "Baldini", "given_name": "Luca", "orcid": "0000-0002-9785-7726" }, { "family_name": "Baumgartner", "given_name": "Wayne H.", "orcid": "0000-0002-5106-0463" }, { "family_name": "Bellazzini", "given_name": "Ronaldo", "orcid": "0000-0002-2469-7063" }, { "family_name": "Bongiorno", "given_name": "Stephen D.", "orcid": "0000-0002-0901-2097" }, { "family_name": "Bonino", "given_name": "Raffaella", "orcid": "0000-0002-4264-1215" }, { "family_name": "Brez", "given_name": "Alessandro", "orcid": "0000-0002-9460-1821" }, { "family_name": "Bucciantini", "given_name": "Niccol\u00f2", "orcid": "0000-0002-8848-1392" }, { "family_name": "Castellano", "given_name": "Simone", "orcid": "0000-0003-1111-4292" }, { "family_name": "Cavazzuti", "given_name": "Elisabetta", "orcid": "0000-0001-7150-9638" }, { "family_name": "Chen", "given_name": "Chien-Ting", "orcid": "0000-0002-4945-5079" }, { "family_name": "Ciprini", "given_name": "Stefano", "orcid": "0000-0002-0712-2479" }, { "family_name": "Costa", "given_name": "Enrico", "orcid": "0000-0003-4925-8523" }, { "family_name": "De Rosa", "given_name": "Alessandra", "orcid": "0000-0001-5668-6863" }, { "family_name": "Del Monte", "given_name": "Ettore", "orcid": "0000-0002-3013-6334" }, { "family_name": "Di Gesu", "given_name": "Laura", "orcid": "0000-0002-5614-5028" }, { "family_name": "Di Lalla", "given_name": "Niccol\u00f2", "orcid": "0000-0002-7574-1298" }, { "family_name": "Di Marco", "given_name": "Alessandro", "orcid": "0000-0003-0331-3259" }, { "family_name": "Donnarumma", "given_name": "Immacolata", "orcid": "0000-0002-4700-4549" }, { "family_name": "Doroshenko", "given_name": 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"0000-0001-6158-1708" }, { "family_name": "Kislat", "given_name": "Fabian", "orcid": "0000-0001-7477-0380" }, { "family_name": "Kitaguchi", "given_name": "Takao" }, { "family_name": "Kolodziejczak", "given_name": "Jeffery J.", "orcid": "0000-0002-0110-6136" }, { "family_name": "La Monaca", "given_name": "Fabio", "orcid": "0000-0001-8916-4156" }, { "family_name": "Latronico", "given_name": "Luca", "orcid": "0000-0002-0984-1856" }, { "family_name": "Liodakis", "given_name": "Ioannis", "orcid": "0000-0001-9200-4006" }, { "family_name": "Maldera", "given_name": "Simone", "orcid": "0000-0002-0698-4421" }, { "family_name": "Manfreda", "given_name": "Alberto", "orcid": "0000-0002-0998-4953" }, { "family_name": "Marin", "given_name": "Fr\u00e9d\u00e9ric", "orcid": "0000-0003-4952-0835" }, { "family_name": "Marinucci", "given_name": "Andrea", "orcid": "0000-0002-2055-4946" }, { "family_name": "Marscher", "given_name": "Alan P.", "orcid": "0000-0001-7396-3332" }, { "family_name": "Marshall", "given_name": "Herman L.", "orcid": "0000-0002-6492-1293" }, { "family_name": "Massaro", "given_name": "Francesco", "orcid": "0000-0002-1704-9850" }, { "family_name": "Mitsuishi", "given_name": "Ikuyuki", "orcid": "0000-0002-9901-233X" }, { "family_name": "Mizuno", "given_name": "Tsunefumi", "orcid": "0000-0001-7263-0296" }, { "family_name": "Ng", "given_name": "Chi-Yung", "orcid": "0000-0002-5847-2612" }, { "family_name": "O'Dell", "given_name": "Stephen L.", "orcid": "0000-0002-1868-8056" }, { "family_name": "Omodei", "given_name": "Nicola", "orcid": "0000-0002-5448-7577" }, { "family_name": "Oppedisano", "given_name": "Chiara", "orcid": "0000-0001-6194-4601" }, { "family_name": "Papitto", "given_name": "Alessandro", "orcid": "0000-0001-6289-7413" }, { "family_name": "Pavlov", "given_name": "George G.", "orcid": "0000-0002-7481-5259" }, { "family_name": "Peirson", "given_name": "Abel L.", "orcid": "0000-0001-6292-1911" }, { "family_name": "Perri", "given_name": "Matteo", "orcid": "0000-0003-3613-4409" }, { "family_name": "Pesce-Rollins", "given_name": "Melissa", "orcid": "0000-0003-1790-8018" }, { "family_name": "Pilia", "given_name": "Maura", "orcid": "0000-0001-7397-8091" }, { "family_name": "Possenti", "given_name": "Andrea", "orcid": "0000-0001-5902-3731" }, { "family_name": "Puccetti", "given_name": "Simonetta", "orcid": "0000-0002-2734-7835" }, { "family_name": "Ramsey", "given_name": "Brian D.", "orcid": "0000-0003-1548-1524" }, { "family_name": "Rankin", "given_name": "John", "orcid": "0000-0002-9774-0560" }, { "family_name": "Roberts", "given_name": "Oliver J.", "orcid": "0000-0002-7150-9061" }, { "family_name": "Romani", "given_name": "Roger W.", "orcid": "0000-0001-6711-3286" }, { "family_name": "Sgr\u00f2", "given_name": "Carmelo", "orcid": "0000-0001-5676-6214" }, { "family_name": "Slane", "given_name": "Patrick", "orcid": "0000-0002-6986-6756" }, { "family_name": "Spandre", "given_name": "Gloria", "orcid": "0000-0003-0802-3453" }, { "family_name": "Soffitta", "given_name": "Paolo", "orcid": "0000-0002-7781-4104" }, { "family_name": "Swartz", "given_name": "Douglas A.", "orcid": "0000-0002-2954-4461" }, { "family_name": "Tamagawa", "given_name": "Toru", "orcid": "0000-0002-8801-6263" }, { "family_name": "Tavecchio", "given_name": "Fabrizio", "orcid": "0000-0003-0256-0995" }, { "family_name": "Tawara", "given_name": "Yuzuru" }, { "family_name": "Tennant", "given_name": "Allyn F.", "orcid": "0000-0002-9443-6774" }, { "family_name": "Thomas", "given_name": "Nicholas E.", "orcid": "0000-0003-0411-4606" }, { "family_name": "Tombesi", "given_name": "Francesco", "orcid": "0000-0002-6562-8654" }, { "family_name": "Trois", "given_name": "Alessio", "orcid": "0000-0002-3180-6002" }, { "family_name": "Tsygankov", "given_name": "Sergey S.", "orcid": "0000-0002-9679-0793" }, { "family_name": "Turolla", "given_name": "Roberto", "orcid": "0000-0003-3977-8760" }, { "family_name": "Vink", "given_name": "Jacco", "orcid": "0000-0002-4708-4219" }, { "family_name": "Weisskopf", "given_name": "Martin C.", "orcid": "0000-0002-5270-4240" }, { "family_name": "Wu", "given_name": "Kinwah", "orcid": "0000-0002-7568-8765" }, { "family_name": "Xie", "given_name": "Fei", "orcid": "0000-0002-0105-5826" } ], "abstract": "
\n

The Imaging X-ray Polarimetry Explorer (IXPE) observed the black hole X-ray binary 4U 1630–47 in the steep power-law (or very high) state. The observations reveal a linear polarization degree of the 2–8 keV X-rays of 6.8% ± 0.2% at a position angle of 213 ± 09 east of north (all errors at 1σ confidence level). Whereas the polarization degree increases with energy, the polarization angle stays constant within the accuracy of our measurements. We compare the polarization of the source in the steep power-law state with the previous IXPE measurement of the source in the high soft state. We find that, even though the source flux and spectral shape are significantly different between the high soft state and the steep power-law state, their polarization signatures are similar. Assuming that the polarization of both the thermal and power-law emission components are constant over time, we estimate the power-law component polarization to be 6.8%–7.0% and note that the polarization angle of the thermal and power-law components must be approximately aligned. We discuss the implications for the origin of the power-law component and the properties of the emitting plasma.

\n
", "doi": "10.3847/2041-8213/acfd2c", "issn": "2041-8205", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal Letters", "publication_date": "2023-11-20", "series_number": "1", "volume": "958", "issue": "1", "pages": "L8" }, { "id": "authors:k0jpp-jmg39", "collection": "authors", "collection_id": "k0jpp-jmg39", "cite_using_url": "https://authors.library.caltech.edu/records/k0jpp-jmg39", "type": "article", "title": "Discovery of X-Ray Polarization from the Black Hole Transient Swift J1727.8\u22121613", "author": [ { "family_name": "Veledina", "given_name": "Alexandra", "orcid": "0000-0002-5767-7253" }, { "family_name": "Muleri", "given_name": "Fabio", "orcid": "0000-0003-3331-3794" }, { "family_name": "Dov\u010diak", "given_name": "Michal", "orcid": "0000-0003-0079-1239" }, { "family_name": "Poutanen", "given_name": "Juri", "orcid": "0000-0002-0983-0049" }, { "family_name": "Ratheesh", "given_name": "Ajay", "orcid": "0000-0003-0411-4243" }, { "family_name": "Capitanio", "given_name": "Fiamma", "orcid": "0000-0002-6384-3027" }, { "family_name": "Matt", "given_name": "Giorgio", "orcid": "0000-0002-2152-0916" }, { "family_name": "Soffitta", "given_name": "Paolo", "orcid": "0000-0002-7781-4104" }, { "family_name": "Tennant", "given_name": "Allyn F.", "orcid": "0000-0002-9443-6774" }, { "family_name": "Negro", "given_name": "Michela", "orcid": "0000-0002-6548-5622" }, { "family_name": "Kaaret", "given_name": "Philip", "orcid": "0000-0002-3638-0637" }, { "family_name": "Costa", "given_name": "Enrico", "orcid": "0000-0003-4925-8523" }, { "family_name": "Ingram", "given_name": "Adam", "orcid": "0000-0002-5311-9078" }, { "family_name": "Svoboda", "given_name": "Ji\u0159\u00ed", "orcid": "0000-0003-2931-0742" }, { "family_name": "Krawczynski", "given_name": "Henric", "orcid": "0000-0002-1084-6507" }, { "family_name": "Bianchi", "given_name": "Stefano", "orcid": "0000-0002-4622-4240" }, { "family_name": "Steiner", "given_name": "James F.", "orcid": "0000-0002-5872-6061" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Kravtsov", "given_name": "Vadim", "orcid": "0000-0002-7502-3173" }, { "family_name": "Nitindala", "given_name": "Anagha P.", "orcid": "0009-0002-7109-0202" }, { "family_name": "Ewing", "given_name": "Melissa", "orcid": "0000-0001-9349-8271" }, { "family_name": "Mastroserio", "given_name": "Guglielmo", "orcid": "0000-0003-4216-7936" }, { "family_name": "Marinucci", "given_name": "Andrea", "orcid": "0000-0002-2055-4946" }, { "family_name": "Ursini", "given_name": "Francesco", "orcid": "0000-0001-9442-7897" }, { "family_name": "Tombesi", "given_name": "Francesco", "orcid": "0000-0002-6562-8654" }, { "family_name": "Tsygankov", "given_name": "Sergey S.", "orcid": "0000-0002-9679-0793" }, { "family_name": "Yang", "given_name": "Yi-Jung", "orcid": "0000-0001-9108-573X" }, { "family_name": "Weisskopf", "given_name": "Martin C.", "orcid": "0000-0002-5270-4240" }, { "family_name": "Trushkin", "given_name": "Sergei A.", "orcid": "0000-0002-7586-5856" }, { "family_name": "Egron", "given_name": "Elise", "orcid": "0000-0002-1532-4142" }, { "family_name": "Iacolina", "given_name": "Maria Noemi", "orcid": "0000-0003-4564-3416" }, { "family_name": "Pilia", "given_name": "Maura", "orcid": "0000-0001-7397-8091" }, { "family_name": "Marra", "given_name": "Lorenzo", "orcid": "0009-0001-4644-194X" }, { "family_name": "Miku\u0161incov\u00e1", "given_name": "Romana", "orcid": "0000-0001-7374-843X" }, { "family_name": "Nathan", "given_name": "Edward", "orcid": "0000-0002-9633-9193", "clpid": "Nathan-Edward" }, { "family_name": "Parra", "given_name": "Maxime", "orcid": "0009-0003-8610-853X" }, { "family_name": "Petrucci", "given_name": "Pierre-Olivier", "orcid": "0000-0001-6061-3480" }, { "family_name": "Podgorn\u00fd", "given_name": "Jakub", "orcid": "0000-0001-5418-291X" }, { "family_name": "Tugliani", "given_name": "Stefano", "orcid": "0000-0002-3318-9036" }, { "family_name": "Zane", "given_name": "Silvia", "orcid": "0000-0001-5326-880X" }, { "family_name": "Zhang", "given_name": "Wenda", "orcid": "0000-0003-1702-4917" }, { "family_name": "Agudo", "given_name": "Iv\u00e1n", "orcid": "0000-0002-3777-6182" }, { "family_name": "Antonelli", "given_name": "Lucio A.", "orcid": "0000-0002-5037-9034" }, { "family_name": "Bachetti", "given_name": "Matteo", "orcid": "0000-0002-4576-9337" }, { "family_name": "Baldini", "given_name": "Luca", "orcid": "0000-0002-9785-7726" }, { "family_name": "Baumgartner", "given_name": "Wayne H.", "orcid": "0000-0002-5106-0463" }, { "family_name": "Bellazzini", "given_name": "Ronaldo", "orcid": "0000-0002-2469-7063" }, { "family_name": "Bongiorno", "given_name": "Stephen D.", "orcid": "0000-0002-0901-2097" }, { "family_name": "Bonino", "given_name": "Raffaella", "orcid": "0000-0002-4264-1215" }, { "family_name": "Brez", "given_name": "Alessandro", "orcid": "0000-0002-9460-1821" }, { "family_name": "Bucciantini", "given_name": "Niccol\u00f2", "orcid": "0000-0002-8848-1392" }, { "family_name": "Castellano", "given_name": "Simone", "orcid": "0000-0003-1111-4292" }, { "family_name": "Cavazzuti", "given_name": "Elisabetta", "orcid": "0000-0001-7150-9638" }, { "family_name": "Chen", "given_name": "Chien-Ting", "orcid": "0000-0002-4945-5079" }, { "family_name": "Ciprini", "given_name": "Stefano", "orcid": "0000-0002-0712-2479" }, { "family_name": "De Rosa", "given_name": "Alessandra", "orcid": "0000-0001-5668-6863" }, { "family_name": "Del Monte", "given_name": "Ettore", "orcid": "0000-0002-3013-6334" }, { "family_name": "Di Gesu", "given_name": "Laura", "orcid": "0000-0002-5614-5028" }, { "family_name": "Di Lalla", "given_name": "Niccol\u00f2", "orcid": "0000-0002-7574-1298" }, { "family_name": "Di Marco", "given_name": "Alessandro", "orcid": "0000-0003-0331-3259" }, { "family_name": "Donnarumma", "given_name": "Immacolata", "orcid": "0000-0002-4700-4549" }, { "family_name": "Doroshenko", "given_name": "Victor", "orcid": "0000-0001-8162-1105" }, { "family_name": "Ehlert", "given_name": "Steven R.", "orcid": "0000-0003-4420-2838" }, { "family_name": "Enoto", "given_name": "Teruaki", "orcid": "0000-0003-1244-3100" }, { "family_name": "Evangelista", "given_name": "Yuri", "orcid": "0000-0001-6096-6710" }, { "family_name": "Fabiani", "given_name": "Sergio", "orcid": "0000-0003-1533-0283" }, { "family_name": "Ferrazzoli", "given_name": "Riccardo", "orcid": "0000-0003-1074-8605" }, { "family_name": "Gunji", "given_name": "Shuichi", "orcid": "0000-0002-5881-2445" }, { "family_name": "Hayashida", "given_name": "Kiyoshi" }, { "family_name": "Heyl", "given_name": "Jeremy", "orcid": "0000-0001-9739-367X" }, { "family_name": "Iwakiri", "given_name": "Wataru", "orcid": "0000-0002-0207-9010" }, { "family_name": "Jorstad", "given_name": "Svetlana G.", "orcid": "0000-0001-6158-1708" }, { "family_name": "Karas", "given_name": "Vladimir", "orcid": "0000-0002-5760-0459" }, { "family_name": "Kislat", "given_name": "Fabian", "orcid": "0000-0001-7477-0380" }, { "family_name": "Kitaguchi", "given_name": "Takao" }, { "family_name": "Kolodziejczak", "given_name": "Jeffery J.", "orcid": "0000-0002-0110-6136" }, { "family_name": "La Monaca", "given_name": "Fabio", "orcid": "0000-0001-8916-4156" }, { "family_name": "Latronico", "given_name": "Luca", "orcid": "0000-0002-0984-1856" }, { "family_name": "Liodakis", "given_name": "Ioannis", "orcid": "0000-0001-9200-4006" }, { "family_name": "Maldera", "given_name": "Simone", "orcid": "0000-0002-0698-4421" }, { "family_name": "Manfreda", "given_name": "Alberto", "orcid": "0000-0002-0998-4953" }, { "family_name": "Marin", "given_name": "Fr\u00e9d\u00e9ric", "orcid": "0000-0003-4952-0835" }, { "family_name": "Marscher", "given_name": "Alan P.", "orcid": "0000-0001-7396-3332" }, { "family_name": "Marshall", "given_name": "Herman L.", "orcid": "0000-0002-6492-1293" }, { "family_name": "Massaro", "given_name": "Francesco", "orcid": "0000-0002-1704-9850" }, { "family_name": "Mitsuishi", "given_name": "Ikuyuki", "orcid": "0000-0002-9901-233X" }, { "family_name": "Mizuno", "given_name": "Tsunefumi", "orcid": "0000-0001-7263-0296" }, { "family_name": "Ng", "given_name": "Chi-Yung", "orcid": "0000-0002-5847-2612" }, { "family_name": "O'Dell", "given_name": "Stephen L.", "orcid": "0000-0002-1868-8056" }, { "family_name": "Omodei", "given_name": "Nicola", "orcid": "0000-0002-5448-7577" }, { "family_name": "Oppedisano", "given_name": "Chiara", "orcid": "0000-0001-6194-4601" }, { "family_name": "Papitto", "given_name": "Alessandro", "orcid": "0000-0001-6289-7413" }, { "family_name": "Pavlov", "given_name": "George G.", "orcid": "0000-0002-7481-5259" }, { "family_name": "Peirson", "given_name": "Abel L.", "orcid": "0000-0001-6292-1911" }, { "family_name": "Perri", "given_name": "Matteo", "orcid": "0000-0003-3613-4409" }, { "family_name": "Pesce-Rollins", "given_name": "Melissa", "orcid": "0000-0003-1790-8018" }, { "family_name": "Possenti", "given_name": "Andrea", "orcid": "0000-0001-5902-3731" }, { "family_name": "Puccetti", "given_name": "Simonetta", "orcid": "0000-0002-2734-7835" }, { "family_name": "Ramsey", "given_name": "Brian D.", "orcid": "0000-0003-1548-1524" }, { "family_name": "Rankin", "given_name": "John", "orcid": "0000-0002-9774-0560" }, { "family_name": "Roberts", "given_name": "Oliver J.", "orcid": "0000-0002-7150-9061" }, { "family_name": "Romani", "given_name": "Roger W.", "orcid": "0000-0001-6711-3286" }, { "family_name": "Sgr\u00f2", "given_name": "Carmelo", "orcid": "0000-0001-5676-6214" }, { "family_name": "Slane", "given_name": "Patrick", "orcid": "0000-0002-6986-6756" }, { "family_name": "Spandre", "given_name": "Gloria", "orcid": "0000-0003-0802-3453" }, { "family_name": "Swartz", "given_name": "Douglas A.", "orcid": "0000-0002-2954-4461" }, { "family_name": "Tamagawa", "given_name": "Toru", "orcid": "0000-0002-8801-6263" }, { "family_name": "Tavecchio", "given_name": "Fabrizio", "orcid": "0000-0003-0256-0995" }, { "family_name": "Taverna", "given_name": "Roberto", "orcid": "0000-0002-1768-618X" }, { "family_name": "Tawara", "given_name": "Yuzuru" }, { "family_name": "Thomas", "given_name": "Nicholas E.", "orcid": "0000-0003-0411-4606" }, { "family_name": "Trois", "given_name": "Alessio", "orcid": "0000-0002-3180-6002" }, { "family_name": "Turolla", "given_name": "Roberto", "orcid": "0000-0003-3977-8760" }, { "family_name": "Vink", "given_name": "Jacco", "orcid": "0000-0002-4708-4219" }, { "family_name": "Wu", "given_name": "Kinwah", "orcid": "0000-0002-7568-8765" }, { "family_name": "Xie", "given_name": "Fei", "orcid": "0000-0002-0105-5826" } ], "abstract": "
\n

We report the first detection of the X-ray polarization of the bright transient Swift J1727.8−1613 with the Imaging X-ray Polarimetry Explorer. The observation was performed at the beginning of the 2023 discovery outburst, when the source resided in the bright hard state. We find a time- and energy-averaged polarization degree of 4.1% ± 0.2% and a polarization angle of 22 ± 13 (errors at 68% confidence level; this translates to ∼20σ significance of the polarization detection). This finding suggests that the hot corona emitting the bulk of the detected X-rays is elongated, rather than spherical. The X-ray polarization angle is consistent with that found in submillimeter wavelengths. Since the submillimeter polarization was found to be aligned with the jet direction in other X-ray binaries, this indicates that the corona is elongated orthogonal to the jet.

\n
", "doi": "10.3847/2041-8213/ad0781", "issn": "2041-8205", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal Letters", "publication_date": "2023-11-20", "series_number": "1", "volume": "958", "issue": "1", "pages": "L16" }, { "id": "authors:nktc2-4d554", "collection": "authors", "collection_id": "nktc2-4d554", "cite_using_url": "https://authors.library.caltech.edu/records/nktc2-4d554", "type": "article", "title": "Simultaneous NICER and NuSTAR Observations of the Ultracompact X-Ray Binary 4U 0614+091", "author": [ { "family_name": "Moutard", "given_name": "D. L.", "orcid": "0000-0003-1463-8702" }, { "family_name": "Ludlam", "given_name": "R. M.", "orcid": "0000-0002-8961-939X" }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Altamirano", "given_name": "D.", "orcid": "0000-0002-3422-0074" }, { "family_name": "Buisson", "given_name": "D. J. K." }, { "family_name": "Cackett", "given_name": "E. M.", "orcid": "0000-0002-8294-9281" }, { "family_name": "Chenevez", "given_name": "J.", "orcid": "0000-0002-4397-8370" }, { "family_name": "Degenaar", "given_name": "N.", "orcid": "0000-0002-0092-3548" }, { "family_name": "Fabian", "given_name": "A. C.", "orcid": "0000-0002-9378-4072" }, { "family_name": "Homan", "given_name": "J.", "orcid": "0000-0001-8371-2713" }, { "family_name": "Jaodand", "given_name": "A.", "orcid": "0000-0002-3850-6651", "clpid": "Jaodand-Amruta" }, { "family_name": "Pike", "given_name": "S. N.", "orcid": "0000-0002-8403-0041" }, { "family_name": "Shaw", "given_name": "A. W.", "orcid": "0000-0002-8808-520X" }, { "family_name": "Strohmayer", "given_name": "T. E.", "orcid": "0000-0001-7681-5845" }, { "family_name": "Tomsick", "given_name": "J. A.", "orcid": "0000-0001-5506-9855" }, { "family_name": "Coughenour", "given_name": "B. M.", "orcid": "0000-0003-0870-6465" } ], "abstract": "

We present the first joint NuSTAR and NICER observations of the ultracompact X-ray binary 4U 0614+091. This source shows quasiperiodic flux variations on the timescale of ∼days. We use reflection modeling techniques to study various components of the accretion system as the flux varies. We find that the flux of the reflected emission and the thermal components representing the disk and the compact object trend closely with the overall flux. However, the flux of the power-law component representing the illuminating X-ray corona scales in the opposite direction, increasing as the total flux decreases. During the lowest flux observation, we see evidence of accretion disk truncation from roughly 6 gravitational radii to 11.5 gravitational radii. This is potentially analogous to the truncation seen in black hole low-mass X-ray binaries, which tends to occur during the low/hard state at sufficiently low Eddington ratios.

", "doi": "10.3847/1538-4357/acf4f3", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2023-11-01", "series_number": "1", "volume": "957", "issue": "1", "pages": "27" }, { "id": "authors:1z24r-mjf75", "collection": "authors", "collection_id": "1z24r-mjf75", "cite_using_url": "https://authors.library.caltech.edu/records/1z24r-mjf75", "type": "article", "title": "The Polarized Cosmic Hand: IXPE Observations of PSR B1509\u221258/MSH 15\u22125\u00b2", "author": [ { "family_name": "Romani", "given_name": "Roger W.", "orcid": "0000-0001-6711-3286" }, { "family_name": "Wong", "given_name": "Josephine", "orcid": "0000-0001-6395-2066" }, { "family_name": "Di Lalla", "given_name": "Niccol\u00f3", "orcid": "0000-0002-7574-1298" }, { "family_name": "Omodei", "given_name": "Nicola", "orcid": "0000-0002-5448-7577" }, { "family_name": "Xie", "given_name": "Fei", "orcid": "0000-0002-0105-5826" }, { "family_name": "Ng", "given_name": "C.-Y.", "orcid": "0000-0002-5847-2612" }, { "family_name": "Ferrazzoli", "given_name": "Riccardo", "orcid": "0000-0003-1074-8605" }, { "family_name": "Di Marco", "given_name": "Alessandro", "orcid": "0000-0003-0331-3259" }, { "family_name": "Bucciantini", "given_name": "Niccol\u00f3", "orcid": "0000-0002-8848-1392" }, { "family_name": "Pilia", "given_name": "Maura", "orcid": "0000-0001-7397-8091" }, { "family_name": "Slane", "given_name": "Patrick", "orcid": "0000-0002-6986-6756" }, { "family_name": "Weisskopf", "given_name": "Martin C.", "orcid": "0000-0002-5270-4240" }, { "family_name": "Johnston", "given_name": "Simon", "orcid": "0000-0002-7122-4963" }, { "family_name": "Burgay", "given_name": "Marta", "orcid": "0000-0002-8265-4344" }, { "family_name": "Wei", "given_name": "Deng", "orcid": "0000-0002-9370-4079" }, { "family_name": "Yang", "given_name": "Yi-Jung", "orcid": "0000-0001-9108-573X" }, { "family_name": "Zhang", "given_name": "Shumeng", "orcid": "0000-0002-0007-7214" }, { "family_name": "Antonelli", "given_name": "Lucio A.", "orcid": "0000-0002-5037-9034" }, { "family_name": "Bachetti", "given_name": "Matteo", "orcid": "0000-0002-4576-9337" }, { "family_name": "Baldini", "given_name": "Luca", "orcid": "0000-0002-9785-7726" }, { "family_name": "Baumgartner", "given_name": "Wayne H.", "orcid": "0000-0002-5106-0463" }, { "family_name": "Bellazzini", "given_name": "Ronaldo", "orcid": "0000-0002-2469-7063" }, { "family_name": "Bianchi", "given_name": "Stefano", "orcid": "0000-0002-4622-4240" }, { "family_name": "Bongiorno", "given_name": "Stephen D.", "orcid": "0000-0002-0901-2097" }, { "family_name": "Bonino", "given_name": "Raffaella", "orcid": "0000-0002-4264-1215" }, { "family_name": "Brez", "given_name": "Alessandro", "orcid": "0000-0002-9460-1821" }, { "family_name": "Capitanio", "given_name": "Fiamma", "orcid": "0000-0002-6384-3027" }, { "family_name": "Castellano", "given_name": "Simone", "orcid": "0000-0003-1111-4292" }, { "family_name": "Cavazzuti", "given_name": "Elisabetta", "orcid": "0000-0001-7150-9638" }, { "family_name": "Chen", "given_name": "Chien-Ting", "orcid": "0000-0002-4945-5079" }, { "family_name": "Cibrario", "given_name": "Nicol\u00f3", "orcid": "0000-0003-3842-4493" }, { "family_name": "Ciprini", "given_name": "Stefano", "orcid": "0000-0002-0712-2479" }, { "family_name": "Costa", "given_name": "Enrico", "orcid": "0000-0003-4925-8523" }, { "family_name": "De Rosa", "given_name": "Alessandra", "orcid": "0000-0001-5668-6863" }, { "family_name": "Del Monte", "given_name": "Ettore", "orcid": "0000-0002-3013-6334" }, { "family_name": "Di Gesu", "given_name": "Laura" }, { "family_name": "Donnarumma", "given_name": "Immacolata", "orcid": "0000-0002-4700-4549" }, { "family_name": "Doroshenko", "given_name": "Victor", "orcid": "0000-0001-8162-1105" }, { "family_name": "Dov\u010diak", "given_name": "Michal", "orcid": "0000-0003-0079-1239" }, { "family_name": "Ehlert", "given_name": "Steven R.", "orcid": "0000-0003-4420-2838" }, { "family_name": "Enoto", "given_name": "Teruaki", "orcid": "0000-0003-1244-3100" }, { "family_name": "Evangelista", "given_name": "Yuri", "orcid": "0000-0001-6096-6710" }, { "family_name": "Fabiani", "given_name": "Sergio", "orcid": "0000-0003-1533-0283" }, { "family_name": "Garcia", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Gunji", "given_name": "Shuichi", "orcid": "0000-0002-5881-2445" }, { "family_name": "Hayashida", "given_name": "Kiyoshi" }, { "family_name": "Heyl", "given_name": "Jeremy", "orcid": "0000-0001-9739-367X" }, { "family_name": "Iwakiri", "given_name": "Wataru", "orcid": "0000-0002-0207-9010" }, { "family_name": "Liodakis", "given_name": "Ioannis", "orcid": "0000-0001-9200-4006" }, { "family_name": "Kaaret", "given_name": "Philip", "orcid": "0000-0002-3638-0637" }, { "family_name": "Karas", "given_name": "Vladimir", "orcid": "0000-0002-5760-0459" }, { "family_name": "Kim", "given_name": "Dawoon E.", "orcid": "0000-0001-5717-3736" }, { "family_name": "Kitaguchi", "given_name": "Takao" }, { "family_name": "Kolodziejczak", "given_name": "Jeffery J.", "orcid": "0000-0002-0110-6136" }, { "family_name": "Krawczynski", "given_name": "Henric", "orcid": "0000-0002-1084-6507" }, { "family_name": "La Monaca", "given_name": "Fabio", "orcid": "0000-0001-8916-4156" }, { "family_name": "Latronico", "given_name": "Luca", "orcid": "0000-0002-0984-1856" }, { "family_name": "Madejski", "given_name": "Grzegorz" }, { "family_name": "Maldera", "given_name": "Simone", "orcid": "0000-0002-0698-4421" }, { "family_name": "Manfreda", "given_name": "Alberto", "orcid": "0000-0002-0998-4953" }, { "family_name": "Marin", "given_name": "Fr\u00e9d\u00e9ric", "orcid": "0000-0003-4952-0835" }, { "family_name": "Marinucci", "given_name": "Andrea", "orcid": "0000-0002-2055-4946" }, { "family_name": "Marscher", "given_name": "Alan P.", "orcid": "0000-0001-7396-3332" }, { "family_name": "Marshall", "given_name": "Herman L.", "orcid": "0000-0002-6492-1293" }, { "family_name": "Massaro", "given_name": "Francesco", "orcid": "0000-0002-1704-9850" }, { "family_name": "Matt", "given_name": "Giorgio", "orcid": "0000-0002-2152-0916" }, { "family_name": "Middei", "given_name": "Riccardo", "orcid": "0000-0001-9815-9092" }, { "family_name": "Mitsuishi", "given_name": "Ikuyuki", "orcid": "0000-0002-9901-233X" }, { "family_name": "Mizuno", "given_name": "Tsunefumi", "orcid": "0000-0001-7263-0296" }, { "family_name": "Muleri", "given_name": "Fabio", "orcid": "0000-0003-3331-3794" }, { "family_name": "Negro", "given_name": "Michela", "orcid": "0000-0002-6548-5622" }, { "family_name": "O'Dell", "given_name": "Stephen L.", "orcid": "0000-0002-1868-8056" }, { "family_name": "Oppedisano", "given_name": "Chiara", "orcid": "0000-0001-6194-4601" }, { "family_name": "Pacciani", "given_name": "Luigi", "orcid": "0000-0001-6897-5996" }, { "family_name": "Papitto", "given_name": "Alessandro", "orcid": "0000-0001-6289-7413" }, { "family_name": "Pavlov", "given_name": "George G.", "orcid": "0000-0002-7481-5259" }, { "family_name": "Perri", "given_name": "Matteo", "orcid": "0000-0003-3613-4409" }, { "family_name": "Pesce-Rollins", "given_name": "Melissa", "orcid": "0000-0003-1790-8018" }, { "family_name": "Petrucci", "given_name": "Pierre-Olivier", "orcid": "0000-0001-6061-3480" }, { "family_name": "Possenti", "given_name": "Andrea", "orcid": "0000-0001-5902-3731" }, { "family_name": "Poutanen", "given_name": "Juri", "orcid": "0000-0002-0983-0049" }, { "family_name": "Puccetti", "given_name": "Simonetta", "orcid": "0000-0002-2734-7835" }, { "family_name": "Ramsey", "given_name": "Brian D.", "orcid": "0000-0003-1548-1524" }, { "family_name": "Rankin", "given_name": "John", "orcid": "0000-0002-9774-0560" }, { "family_name": "Ratheesh", "given_name": "Ajay", "orcid": "0000-0003-0411-4243" }, { "family_name": "Roberts", "given_name": "Oliver J.", "orcid": "0000-0002-7150-9061" }, { "family_name": "Sgr\u00f3", "given_name": "Carmelo", "orcid": "0000-0001-5676-6214" }, { "family_name": "Spandre", "given_name": "Gloria", "orcid": "0000-0003-0802-3453" }, { "family_name": "Swartz", "given_name": "Douglas A.", "orcid": "0000-0002-2954-4461" }, { "family_name": "Tamagawa", "given_name": "Toru", "orcid": "0000-0002-8801-6263" }, { "family_name": "Tavecchio", "given_name": "Fabrizio", "orcid": "0000-0003-0256-0995" }, { "family_name": "Taverna", "given_name": "Roberto", "orcid": "0000-0002-1768-618X" }, { "family_name": "Tawara", "given_name": "Yuzuru" }, { "family_name": "Tennant", "given_name": "Allyn F.", "orcid": "0000-0002-9443-6774" }, { "family_name": "Thomas", "given_name": "Nicholas E.", "orcid": "0000-0003-0411-4606" }, { "family_name": "Tombesi", "given_name": "Francesco", "orcid": "0000-0002-6562-8654" }, { "family_name": "Trois", "given_name": "Alessio", "orcid": "0000-0002-3180-6002" }, { "family_name": "Tsygankov", "given_name": "Sergey", "orcid": "0000-0002-9679-0793" }, { "family_name": "Turolla", "given_name": "Roberto", "orcid": "0000-0003-3977-8760" }, { "family_name": "Vink", "given_name": "Jacco", "orcid": "0000-0002-4708-4219" }, { "family_name": "Wu", "given_name": "Kinwah", "orcid": "0000-0002-7568-8765" }, { "family_name": "Zane", "given_name": "Silvia", "orcid": "0000-0001-5326-880X" } ], "abstract": "

We describe IXPE polarization observations of the pulsar wind nebula (PWN) MSH 15−52, the \"Cosmic Hand.\" We find X-ray polarization across the PWN, with B-field vectors generally aligned with filamentary X-ray structures. High-significance polarization is seen in arcs surrounding the pulsar and toward the end of the \"jet,\" with polarization degree PD > 70%, thus approaching the maximum allowed synchrotron value. In contrast, the base of the jet has lower polarization, indicating a complex magnetic field at significant angle to the jet axis. We also detect significant polarization from PSR B1509−58 itself. Although only the central pulse phase bin of the pulse has high individual significance, flanking bins provide lower-significance detections and, in conjunction with the X-ray image and radio polarization, can be used to constrain rotating vector model solutions for the pulsar geometry.

", "doi": "10.3847/1538-4357/acfa02", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2023-11-01", "series_number": "1", "volume": "957", "issue": "1", "pages": "23" }, { "id": "authors:jzm3c-jn583", "collection": "authors", "collection_id": "jzm3c-jn583", "cite_using_url": "https://authors.library.caltech.edu/records/jzm3c-jn583", "type": "article", "title": "Magnetic Structures and Turbulence in SN 1006 Revealed with Imaging X-Ray Polarimetry", "author": [ { "family_name": "Zhou", "given_name": "Ping", "orcid": "0000-0002-5683-822X", "clpid": "Zhou-Ping" }, { "family_name": "Prokhorov", "given_name": "Dmitry", "orcid": "0000-0001-6511-4330" }, { "family_name": "Ferrazzoli", "given_name": "Riccardo", "orcid": "0000-0003-1074-8605" }, { "family_name": "Yang", "given_name": "Yi-Jung", "orcid": "0000-0001-9108-573X" }, { "family_name": "Slane", "given_name": "Patrick", "orcid": "0000-0002-6986-6756" }, { "family_name": "Vink", "given_name": "Jacco", "orcid": "0000-0002-4708-4219" }, { "family_name": "Silvestri", "given_name": "Stefano", "orcid": "0000-0002-8665-0105" }, { "family_name": "Bucciantini", "given_name": "Niccol\u00f2", "orcid": "0000-0002-8848-1392" }, { "family_name": "Reynoso", "given_name": "Estela", "orcid": "0000-0002-1875-7701" }, { "family_name": "Moffett", "given_name": "David", "orcid": "0000-0003-1821-4966" }, { "family_name": "Soffitta", "given_name": "Paolo", "orcid": "0000-0002-7781-4104" }, { "family_name": "Swartz", "given_name": "Doug", "orcid": "0000-0002-2954-4461" }, { "family_name": "Kaaret", "given_name": "Philip", "orcid": "0000-0002-3638-0637" }, { "family_name": "Baldini", "given_name": "Luca", "orcid": "0000-0002-9785-7726" }, { "family_name": "Costa", "given_name": "Enrico", "orcid": "0000-0003-4925-8523" }, { "family_name": "Ng", "given_name": "C.-Y.", "orcid": "0000-0002-5847-2612" }, { "family_name": "Kim", "given_name": "Dawoon E.", "orcid": "0000-0001-5717-3736" }, { "family_name": "Doroshenko", "given_name": "Victor", "orcid": "0000-0001-8162-1105" }, { "family_name": "Ehlert", "given_name": "Steven R.", "orcid": "0000-0003-4420-2838" }, { "family_name": "Heyl", "given_name": "Jeremy", "orcid": "0000-0001-9739-367X" }, { "family_name": "Marin", "given_name": "Fr\u00e9d\u00e9ric", "orcid": "0000-0003-4952-0835" }, { "family_name": "Mizuno", "given_name": "Tsunefumi", "orcid": "0000-0001-7263-0296" }, { "family_name": "Pesce-Rollins", "given_name": "Melissa", "orcid": "0000-0003-1790-8018" }, { "family_name": "Sgr\u00f2", "given_name": "Carmelo", "orcid": "0000-0001-5676-6214" }, { "family_name": "Tamagawa", "given_name": "Toru", "orcid": "0000-0002-8801-6263" }, { "family_name": "Weisskopf", "given_name": "Martin C.", "orcid": "0000-0002-5270-4240" }, { "family_name": "Xie", "given_name": "Fei", "orcid": "0000-0002-0105-5826" }, { "family_name": "Agudo", "given_name": "Iv\u00e1n", "orcid": "0000-0002-3777-6182" }, { "family_name": "Antonelli", "given_name": "Lucio A.", "orcid": "0000-0002-5037-9034" }, { "family_name": "Bachetti", "given_name": "Matteo", "orcid": "0000-0002-4576-9337" }, { "family_name": "Baumgartner", "given_name": "Wayne H.", "orcid": "0000-0002-5106-0463" }, { "family_name": "Bellazzini", "given_name": "Ronaldo", "orcid": "0000-0002-2469-7063" }, { "family_name": "Bianchi", "given_name": "Stefano", "orcid": "0000-0002-4622-4240" }, { "family_name": "Bongiorno", "given_name": "Stephen D.", "orcid": "0000-0002-0901-2097" }, { "family_name": "Bonino", "given_name": "Raffaella", "orcid": "0000-0002-4264-1215" }, { "family_name": "Brez", "given_name": "Alessandro", "orcid": "0000-0002-9460-1821" }, { "family_name": "Capitanio", "given_name": "Fiamma", "orcid": "0000-0002-6384-3027" }, { "family_name": "Castellano", "given_name": "Simone", "orcid": "0000-0003-1111-4292" }, { "family_name": "Cavazzuti", "given_name": "Elisabetta", "orcid": "0000-0001-7150-9638" }, { "family_name": "Chen", "given_name": "Chien-Ting", "orcid": "0000-0002-4945-5079" }, { "family_name": "Ciprini", "given_name": "Stefano", "orcid": "0000-0002-0712-2479" }, { "family_name": "De Rosa", "given_name": "Alessandra", "orcid": "0000-0001-5668-6863" }, { "family_name": "Del Monte", "given_name": "Ettore", "orcid": "0000-0002-3013-6334" }, { "family_name": "Di Gesu", "given_name": "Laura", "orcid": "0000-0002-5614-5028" }, { "family_name": "Di Lalla", "given_name": "Niccol\u00f2", "orcid": "0000-0002-7574-1298" }, { "family_name": "Di Marco", "given_name": "Alessandro", "orcid": "0000-0003-0331-3259" }, { "family_name": "Donnarumma", "given_name": "Immacolata", "orcid": "0000-0002-4700-4549" }, { "family_name": "Dov\u010diak", "given_name": "Michal", "orcid": "0000-0003-0079-1239" }, { "family_name": "Enoto", "given_name": "Teruaki", "orcid": "0000-0003-1244-3100" }, { "family_name": "Evangelista", "given_name": "Yuri", "orcid": "0000-0001-6096-6710" }, { "family_name": "Fabiani", "given_name": "Sergio", "orcid": "0000-0003-1533-0283" }, { "family_name": "Garcia", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Gunji", "given_name": "Shuichi", "orcid": "0000-0002-5881-2445" }, { "family_name": "Hayashida", "given_name": "Kiyoshi" }, { "family_name": "Iwakiri", "given_name": "Wataru", "orcid": "0000-0002-0207-9010" }, { "family_name": "Jorstad", "given_name": "Svetlana G.", "orcid": "0000-0001-6158-1708" }, { "family_name": "Kislat", "given_name": "Fabian", "orcid": "0000-0001-7477-0380" }, { "family_name": "Karas", "given_name": "Vladimir", "orcid": "0000-0002-5760-0459" }, { "family_name": "Kitaguchi", "given_name": "Takao" }, { "family_name": "Kolodziejczak", "given_name": "Jeffery J.", "orcid": "0000-0002-0110-6136" }, { "family_name": "Krawczynski", "given_name": "Henric", "orcid": "0000-0002-1084-6507" }, { "family_name": "La Monaca", "given_name": "Fabio", "orcid": "0000-0001-8916-4156" }, { 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"0000-0002-2734-7835" }, { "family_name": "Ramsey", "given_name": "Brian D.", "orcid": "0000-0003-1548-1524" }, { "family_name": "Rankin", "given_name": "John", "orcid": "0000-0002-9774-0560" }, { "family_name": "Ratheesh", "given_name": "Ajay", "orcid": "0000-0003-0411-4243" }, { "family_name": "Roberts", "given_name": "Oliver", "orcid": "0000-0002-7150-9061" }, { "family_name": "Romani", "given_name": "Roger W.", "orcid": "0000-0001-6711-3286" }, { "family_name": "Spandre", "given_name": "Gloria", "orcid": "0000-0003-0802-3453" }, { "family_name": "Tavecchio", "given_name": "Fabrizio", "orcid": "0000-0003-0256-0995" }, { "family_name": "Taverna", "given_name": "Roberto", "orcid": "0000-0002-1768-618X" }, { "family_name": "Tawara", "given_name": "Yuzuru" }, { "family_name": "Tennant", "given_name": "Allyn F.", "orcid": "0000-0002-9443-6774" }, { "family_name": "Thomas", "given_name": "Nicholas E.", "orcid": "0000-0003-0411-4606" }, { "family_name": "Tombesi", "given_name": "Francesco", "orcid": "0000-0002-6562-8654" }, { "family_name": "Trois", "given_name": "Alessio", "orcid": "0000-0002-3180-6002" }, { "family_name": "Tsygankov", "given_name": "Sergey S.", "orcid": "0000-0002-9679-0793" }, { "family_name": "Turolla", "given_name": "Roberto", "orcid": "0000-0003-3977-8760" }, { "family_name": "Wu", "given_name": "Kinwah", "orcid": "0000-0002-7568-8765" }, { "family_name": "Zane", "given_name": "Silvia", "orcid": "0000-0001-5326-880X" } ], "abstract": "
\n

Young supernova remnants strongly modify the surrounding magnetic fields, which in turn play an essential role in accelerating cosmic rays (CRs). The X-ray polarization measurements probe magnetic field morphology and turbulence at the immediate acceleration site. We report the X-ray polarization distribution in the northeastern shell of SN 1006 from a 1 Ms observation with the Imaging X-ray Polarimetry Explorer. We found an average polarization degree of 22.4% ± 3.5% and an average polarization angle of −45.°4 ± 4.°5 (measured on the plane of the sky from north to east). The X-ray polarization angle distribution reveals that the magnetic fields immediately behind the shock in the northeastern shell of SN 1006 are nearly parallel to the shock normal or radially distributed, similar to that in the radio observations, and consistent with the quasi-parallel CR acceleration scenario. The X-ray emission is marginally more polarized than that in the radio band. The X-ray polarization degree of SN 1006 is much larger than that in Cas A and Tycho, together with the relatively tenuous and smooth ambient medium of the remnant, favoring that CR-induced instabilities set the magnetic turbulence in SN 1006, and CR acceleration is environment-dependent.

\n
", "doi": "10.3847/1538-4357/acf3e6", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2023-11-01", "series_number": "1", "volume": "957", "issue": "1", "pages": "55" }, { "id": "authors:0qx4b-v9360", "collection": "authors", "collection_id": "0qx4b-v9360", "cite_using_url": "https://authors.library.caltech.edu/records/0qx4b-v9360", "type": "article", "title": "Discovery of X-ray polarization angle rotation in the jet from blazar Mrk 421", "author": [ { "family_name": "Di Gesu", "given_name": "Laura", "orcid": "0000-0002-5614-5028", "clpid": "Di-Gesu-Laura" }, { "family_name": "Marshall", "given_name": "Herman L.", "orcid": "0000-0002-6492-1293" }, { "family_name": "Ehlert", "given_name": "Steven R.", "orcid": "0000-0003-4420-2838" }, { "family_name": "Kim", "given_name": "Dawoon E.", "orcid": "0000-0001-5717-3736" }, { "family_name": "Donnarumma", "given_name": "Immacolata", "orcid": "0000-0002-4700-4549" }, { "family_name": "Tavecchio", "given_name": "Fabrizio", "orcid": "0000-0003-0256-0995" }, { "family_name": "Liodakis", "given_name": "Ioannis", "orcid": "0000-0001-9200-4006" }, { "family_name": "Kiehlmann", "given_name": "Sebastian", "orcid": "0000-0001-6314-9177" }, { "family_name": "Agudo", "given_name": "Iv\u00e1n", "orcid": "0000-0002-3777-6182" }, { "family_name": "Jorstad", "given_name": "Svetlana G.", "orcid": "0000-0001-6158-1708" }, { "family_name": "Muleri", "given_name": "Fabio", "orcid": "0000-0003-3331-3794" }, { "family_name": "Marscher", "given_name": "Alan P.", "orcid": "0000-0001-7396-3332" }, { "family_name": "Puccetti", "given_name": "Simonetta", "orcid": "0000-0002-2734-7835" }, { "family_name": "Middei", "given_name": "Riccardo", "orcid": "0000-0001-9815-9092" }, { "family_name": "Perri", "given_name": "Matteo", "orcid": "0000-0003-3613-4409" }, { "family_name": "Pacciani", "given_name": "Luigi", "orcid": "0000-0001-6897-5996" }, { "family_name": "Negro", 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"family_name": "Tamagawa", "given_name": "Toru", "orcid": "0000-0002-8801-6263" }, { "family_name": "Taverna", "given_name": "Roberto", "orcid": "0000-0002-1768-618X" }, { "family_name": "Tawara", "given_name": "Yuzuru" }, { "family_name": "Thomas", "given_name": "Nicholas E.", "orcid": "0000-0003-0411-4606" }, { "family_name": "Tombesi", "given_name": "Francesco", "orcid": "0000-0002-6562-8654" }, { "family_name": "Trois", "given_name": "Alessio", "orcid": "0000-0002-3180-6002" }, { "family_name": "Tsygankov", "given_name": "Sergey S.", "orcid": "0000-0002-9679-0793" }, { "family_name": "Turolla", "given_name": "Roberto", "orcid": "0000-0003-3977-8760" }, { "family_name": "Vink", "given_name": "Jacco", "orcid": "0000-0002-4708-4219" }, { "family_name": "Weisskopf", "given_name": "Martin C.", "orcid": "0000-0002-5270-4240" }, { "family_name": "Xie", "given_name": "Fei", "orcid": "0000-0002-0105-5826" }, { "family_name": "Zane", "given_name": "Silvia", "orcid": "0000-0001-5326-880X" } ], "abstract": "The magnetic-field conditions in astrophysical relativistic jets can be probed by multiwavelength polarimetry, which has been recently extended to X-rays. For example, one can track how the magnetic field changes in the flow of the radiating particles by observing rotations of the electric vector position angle \u03a8. Here we report the discovery of a \u03a8_X rotation in the X-ray band in the blazar Markarian\u2009421 at an average flux state. Across the 5\u2009days of Imaging X-ray Polarimetry Explorer observations on 4\u20136 and 7\u20139 June 2022, \u03a8_X rotated in total by \u2265360\u00b0. Over the two respective date ranges, we find constant, within uncertainties, rotation rates (80\u2009\u00b1\u20099\u00b0 per day and 91\u2009\u00b1\u20098\u00b0 per day) and polarization degrees (\u03a0_X =\u200910%\u2009\u00b1\u20091%). Simulations of a random walk of the polarization vector indicate that it is unlikely that such rotation(s) are produced by a stochastic process. The X-ray-emitting site does not completely overlap the radio, infrared and optical emission sites, as no similar rotation of \u03a8 was observed in quasi-simultaneous data at longer wavelengths. We propose that the observed rotation was caused by a helical magnetic structure in the jet, illuminated in the X-rays by a localized shock propagating along this helix. The optically emitting region probably lies in a sheath surrounding an inner spine where the X-ray radiation is released.", "doi": "10.1038/s41550-023-02032-7", "issn": "2397-3366", "publisher": "Nature Publishing Group", "publication": "Nature Astronomy", "publication_date": "2023-10", "volume": "7", "pages": "1245-1258" }, { "id": "authors:9s17r-hfe98", "collection": "authors", "collection_id": "9s17r-hfe98", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230725-746017000.23", "type": "article", "title": "High-density Reflection Spectroscopy of Black Hole X-Ray Binaries in the Hard State", "author": [ { "family_name": "Liu", "given_name": "Honghui", "orcid": "0000-0003-2845-1009", "clpid": "Liu-Honghui" }, { "family_name": "Jiang", "given_name": "Jiachen", "orcid": "0000-0002-9639-4352", "clpid": "Jiang-Jiachen" }, { "family_name": "Zhang", "given_name": "Zuobin", "orcid": "0000-0003-0847-1299", "clpid": "Zhang-Zuobin" }, { "family_name": "Bambi", "given_name": "Cosimo", "orcid": "0000-0002-3180-9502", "clpid": "Bambi-Cosimo" }, { "family_name": "Fabian", "given_name": "Andrew C.", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-Andrew-C" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Ingram", "given_name": "Adam", "orcid": "0000-0002-5311-9078", "clpid": "Ingram-Adam" }, { "family_name": "Kara", "given_name": "Erin", "orcid": "0000-0003-0172-0854", "clpid": "Kara-Erin" }, { "family_name": "Steiner", "given_name": "James F.", "orcid": "0000-0002-5872-6061", "clpid": "Steiner-James-F" }, { "family_name": "Tomsick", "given_name": "John A.", "orcid": "0000-0001-5506-9855", "clpid": "Tomsick-John-A" }, { "family_name": "Walton", "given_name": "Dominic J.", "orcid": "0000-0001-5819-3552", "clpid": "Walton-Dominic-J" }, { "family_name": "Young", "given_name": "Andrew J.", "orcid": "0000-0003-3626-9151", "clpid": "Young-Andrew-J" } ], "abstract": "We present a high-density relativistic reflection analysis of 21 spectra of six black hole X-ray binaries in the hard state with data from NuSTAR and Swift. We find that 76% of the observations in our sample require a disk density higher than the 10\u00b9\u2075 cm\u207b\u00b3 assumed in the previous reflection analysis. Compared with the measurements from active galactic nuclei, stellar mass black holes have higher disk densities. Our fits indicate that the inner disk radius is close to the innermost stable circular orbit in the luminous hard state. The coronal temperatures are significantly lower than the prediction of a purely thermal plasma, which can be explained with a hybrid plasma model. If the disk density is fixed at 10\u00b9\u2075 cm\u207b\u00b3, the disk ionization parameter is overestimated while the inner disk radius is unaffected.", "doi": "10.3847/1538-4357/acd8b9", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2023-07-10", "series_number": "2", "volume": "951", "issue": "2", "pages": "Art. No. 145" }, { "id": "authors:61ems-vbe67", "collection": "authors", "collection_id": "61ems-vbe67", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230630-22232000.4", "type": "article", "title": "X-ray polarization evidence for a 200-year-old flare of Sgr A*", "author": [ { "family_name": "Marin", "given_name": "Fr\u00e9d\u00e9ric", "orcid": "0000-0003-4952-0835", "clpid": "Marin-Fr\u00e9d\u00e9ric" }, { "family_name": "Churazov", "given_name": "Eugene", "orcid": "0000-0002-0322-884X" }, { "family_name": "Khabibullin", "given_name": "Ildar", "orcid": "0000-0003-3701-5882" }, { "family_name": "Ferrazzoli", "given_name": "Riccardo", "orcid": "0000-0003-1074-8605" }, { "family_name": "Di Gesu", "given_name": "Laura", "orcid": "0000-0002-5614-5028" }, { "family_name": "Barnouin", "given_name": "Thibault", "orcid": "0000-0003-1340-5675" }, { "family_name": "Di Marco", "given_name": "Alessandro", "orcid": "0000-0003-0331-3259" }, { "family_name": "Middei", "given_name": "Riccardo", "orcid": "0000-0001-9815-9092" }, { "family_name": "Vikhlinin", "given_name": "Alexey" }, { "family_name": "Costa", "given_name": "Enrico", "orcid": "0000-0003-4925-8523" }, { "family_name": "Soffitta", "given_name": "Paolo", "orcid": "0000-0002-7781-4104" }, { "family_name": "Muleri", "given_name": "Fabio", "orcid": "0000-0003-3331-3794" }, { "family_name": "Sunyaev", "given_name": "Rashid", "orcid": "0000-0002-2764-7192" }, { "family_name": "Forman", "given_name": "William R.", "orcid": "0000-0002-9478-1682" }, { "family_name": "Kraft", "given_name": "Ralph", "orcid": "0000-0002-0765-0511" }, { "family_name": "Bianchi", "given_name": "Stefano", "orcid": "0000-0002-4622-4240" }, { "family_name": "Donnarumma", "given_name": "Immacolata", "orcid": "0000-0002-4700-4549" }, { "family_name": "Petrucci", "given_name": "Pierre-Olivier", "orcid": "0000-0001-6061-3480" }, { "family_name": "Enoto", "given_name": "Teruaki", "orcid": "0000-0003-1244-3100" }, { "family_name": "Agudo", "given_name": "Iv\u00e1n", "orcid": "0000-0002-3777-6182" }, { "family_name": "Antonelli", "given_name": "Lucio A.", "orcid": "0000-0002-5037-9034" }, { "family_name": "Bachetti", "given_name": "Matteo", "orcid": "0000-0002-4576-9337" }, { "family_name": "Baldini", "given_name": "Luca", "orcid": "0000-0002-9785-7726" }, { "family_name": "Baumgartner", "given_name": "Wayne H.", "orcid": "0000-0002-5106-0463" }, { "family_name": "Bellazzini", "given_name": "Ronaldo", "orcid": "0000-0002-2469-7063" }, { "family_name": "Bongiorno", "given_name": "Stephen D.", "orcid": "0000-0002-0901-2097" }, { "family_name": "Bonino", "given_name": "Raffaella", "orcid": "0000-0002-4264-1215" }, { "family_name": "Brez", "given_name": "Alessandro", "orcid": "0000-0002-9460-1821" }, { "family_name": "Bucciantini", "given_name": "Niccol\u00f2", "orcid": "0000-0002-8848-1392" }, { "family_name": "Capitanio", "given_name": "Fiamma", "orcid": "0000-0002-6384-3027" }, { "family_name": "Castellano", "given_name": "Simone", "orcid": "0000-0003-1111-4292" }, { "family_name": "Cavazzuti", "given_name": "Elisabetta", "orcid": "0000-0001-7150-9638" }, { "family_name": "Chen", "given_name": "Chien-Ting", "orcid": "0000-0002-4945-5079" }, { "family_name": "Ciprini", "given_name": "Stefano", "orcid": "0000-0002-0712-2479" }, { "family_name": "De Rosa", "given_name": "Alessandra", "orcid": "0000-0001-5668-6863" }, { "family_name": "Del Monte", "given_name": "Ettore", "orcid": "0000-0002-3013-6334" }, { "family_name": "Di Lalla", "given_name": "Niccol\u00f2", "orcid": "0000-0002-7574-1298" }, { "family_name": "Doroshenko", "given_name": "Victor", "orcid": "0000-0001-8162-1105" }, { "family_name": "Dov\u010diak", "given_name": "Michal", "orcid": "0000-0003-0079-1239" }, { "family_name": "Ehlert", "given_name": "Steven R.", "orcid": "0000-0003-4420-2838" }, { "family_name": "Evangelista", "given_name": "Yuri", "orcid": "0000-0001-6096-6710" }, { "family_name": "Fabiani", "given_name": "Sergio", "orcid": "0000-0003-1533-0283" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Gunji", "given_name": "Shuichi", "orcid": "0000-0002-5881-2445" }, { "family_name": "Hayashida", "given_name": "Kiyoshi", "orcid": "0000-0002-0110-6136" }, { "family_name": "Heyl", "given_name": "Jeremy", "orcid": "0000-0001-9739-367X" }, { "family_name": "Ingram", "given_name": "Adam", "orcid": "0000-0002-5311-9078" }, { "family_name": "Iwakiri", "given_name": "Wataru", "orcid": "0000-0002-0207-9010" }, { "family_name": "Jorstad", "given_name": "Svetlana G.", "orcid": "0000-0001-6158-1708" }, { "family_name": "Kaaret", "given_name": "Philip", "orcid": "0000-0002-3638-0637" }, { "family_name": "Karas", "given_name": "Vladimir", "orcid": "0000-0002-5760-0459" }, { "family_name": "Kitaguchi", "given_name": "Takao" }, { "family_name": "Krawczynski", "given_name": "Henric", "orcid": "0000-0002-1084-6507" }, { "family_name": "La Monaca", "given_name": "Fabio", "orcid": "0000-0001-8916-4156" }, { "family_name": "Latronico", "given_name": "Luca", "orcid": "0000-0002-0984-1856" }, { "family_name": "Liodakis", "given_name": "Ioannis", "orcid": "0000-0001-9200-4006" }, { "family_name": "Maldera", "given_name": "Simone", "orcid": "0000-0002-0698-4421" }, { "family_name": "Manfreda", "given_name": "Alberto", "orcid": "0000-0002-0998-4953" }, { "family_name": "Marinucci", "given_name": "Andrea", "orcid": "0000-0002-2055-4946" }, { "family_name": "Marscher", "given_name": "Alan P.", "orcid": "0000-0001-7396-3332" }, { "family_name": "Marshall", "given_name": "Herman L.", "orcid": "0000-0002-6492-1293" }, { "family_name": "Massaro", "given_name": "Francesco", "orcid": "0000-0002-1704-9850" }, { "family_name": "Matt", "given_name": "Giorgio", "orcid": "0000-0002-2152-0916" }, { "family_name": "Mitsuishi", "given_name": "Ikuyuki" }, { "family_name": "Mizuno", "given_name": "Tsunefumi", "orcid": "0000-0001-7263-0296" }, { "family_name": "Negro", "given_name": "Michela", "orcid": "0000-0002-6548-5622" }, { "family_name": "Ng", "given_name": "C.-Y.", "orcid": "0000-0002-5847-2612" }, { "family_name": "O'Dell", "given_name": "Stephen L.", "orcid": "0000-0002-1868-8056" }, { "family_name": "Omodei", "given_name": "Nicola", "orcid": "0000-0002-5448-7577" }, { "family_name": "Oppedisano", "given_name": "Chiara", "orcid": "0000-0001-6194-4601" }, { "family_name": "Papitto", "given_name": "Alessandro", "orcid": "0000-0001-6289-7413" }, { "family_name": "Pavlov", "given_name": "George G.", "orcid": "0000-0002-7481-5259" }, { "family_name": "Peirson", "given_name": "Abel L.", "orcid": "0000-0001-6292-1911" }, { "family_name": "Perri", "given_name": "Matteo", "orcid": "0000-0003-3613-4409" }, { "family_name": "Pesce-Rollins", "given_name": "Melissa", "orcid": "0000-0003-1790-8018" }, { "family_name": "Pilia", "given_name": "Maura", "orcid": "0000-0001-7397-8091" }, { "family_name": "Possenti", "given_name": "Andrea", "orcid": "0000-0001-5902-3731" }, { "family_name": "Poutanen", "given_name": "Juri", "orcid": "0000-0002-0983-0049" }, { "family_name": "Puccetti", "given_name": "Simonetta", "orcid": "0000-0002-2734-7835" }, { "family_name": "Ramsey", "given_name": "Brian D.", "orcid": "0000-0003-1548-1524" }, { "family_name": "Rankin", "given_name": "John", "orcid": "0000-0002-9774-0560" }, { "family_name": "Ratheesh", "given_name": "Ajay", "orcid": "0000-0003-0411-4243" }, { "family_name": "Roberts", "given_name": "Oliver J.", "orcid": "0000-0002-7150-9061" }, { "family_name": "Romani", "given_name": "Roger W.", "orcid": "0000-0001-6711-3286" }, { "family_name": "Sgr\u00f2", "given_name": "Carmelo", "orcid": "0000-0001-5676-6214" }, { "family_name": "Slane", "given_name": "Patrick", "orcid": "0000-0002-6986-6756" }, { "family_name": "Spandre", "given_name": "Gloria", "orcid": "0000-0003-0802-3453" }, { "family_name": "Swartz", "given_name": "Doug", "orcid": "0000-0002-2954-4461" }, { "family_name": "Tamagawa", "given_name": "Toru", "orcid": "0000-0002-8801-6263" }, { "family_name": "Tavecchio", "given_name": "Fabrizio", "orcid": "0000-0003-0256-0995" }, { "family_name": "Taverna", "given_name": "Roberto", "orcid": "0000-0002-1768-618X" }, { "family_name": "Tawara", "given_name": "Yuzuru" }, { "family_name": "Tennant", "given_name": "Allyn F.", "orcid": "0000-0002-9443-6774" }, { "family_name": "Thomas", "given_name": "Nicholas E.", "orcid": "0000-0003-0411-4606" }, { "family_name": "Tombesi", "given_name": "Francesco", "orcid": "0000-0002-6562-8654" }, { "family_name": "Trois", "given_name": "Alessio", "orcid": "0000-0002-3180-6002" }, { "family_name": "Tsygankov", "given_name": "Sergey S.", "orcid": "0000-0002-9679-0793" }, { "family_name": "Turolla", "given_name": "Roberto", "orcid": "0000-0003-3977-8760" }, { "family_name": "Vink", "given_name": "Jacco", "orcid": "0000-0002-4708-4219" }, { "family_name": "Weisskopf", "given_name": "Martin C.", "orcid": "0000-0002-5270-4240" }, { "family_name": "Wu", "given_name": "Kinwah", "orcid": "0000-0002-7568-8765" }, { "family_name": "Xie", "given_name": "Fei", "orcid": "0000-0002-0105-5826" }, { "family_name": "Zane", "given_name": "Silvia", "orcid": "0000-0001-5326-880X" } ], "abstract": "The centre of the Milky Way Galaxy hosts a black hole with a solar mass of about 4\u2009million (Sagittarius A* (Sgr A)) that is very quiescent at present with a luminosity many orders of magnitude below those of active galactic nuclei1. Reflection of X-rays from Sgr\u2009A* by dense gas in the Galactic Centre region offers a means to study its past flaring activity on timescales of hundreds and thousands of years2. The shape of the X-ray continuum and the strong fluorescent iron line observed from giant molecular clouds in the vicinity of Sgr\u2009A* are consistent with the reflection scenario3,4,5. If this interpretation is correct, the reflected continuum emission should be polarized6. Here we report observations of polarized X-ray emission in the direction of the molecular clouds in the Galactic Centre using the Imaging X-ray Polarimetry Explorer. We measure a polarization degree of 31%\u2009\u00b1\u200911%, and a polarization angle of \u221248\u00b0\u2009\u00b1\u200911\u00b0. The polarization angle is consistent with Sgr\u2009A* being the primary source of the emission, and the polarization degree implies that some 200 years ago, the X-ray luminosity of Sgr\u2009A* was briefly comparable to that of a Seyfert galaxy.", "doi": "10.1038/s41586-023-06064-x", "issn": "0028-0836", "publisher": "Nature Publishing Group", "publication": "Nature", "publication_date": "2023-07-06", "series_number": "7968", "volume": "619", "issue": "7968", "pages": "41-45" }, { "id": "authors:je87z-k6n95", "collection": "authors", "collection_id": "je87z-k6n95", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230717-55891100.19", "type": "article", "title": "Investigating the Impact of Vertically Extended Coronae on X-Ray Reverberation Mapping", "author": [ { "family_name": "Lucchini", "given_name": "Matteo", "orcid": "0000-0002-2235-3347", "clpid": "Lucchini-Matteo" }, { "family_name": "Mastroserio", "given_name": "Guglielmo", "orcid": "0000-0003-4216-7936", "clpid": "Mastroserio-Guglielmo" }, { "family_name": "Wang", "given_name": "Jingyi", "orcid": "0000-0002-1742-2125", "clpid": "Wang-Jingyi" }, { "family_name": "Kara", "given_name": "Erin", "orcid": "0000-0003-0172-0854", "clpid": "Kara-Erin" }, { "family_name": "Ingram", "given_name": "Adam", "orcid": "0000-0002-5311-9078", "clpid": "Ingram-Adam" }, { "family_name": "Garcia", "given_name": "Javier", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-T" }, { "family_name": "van der Klis", "given_name": "Michiel", "orcid": "0000-0003-0070-9872", "clpid": "van-der-Klis-Michiel" }, { "family_name": "K\u00f6nig", "given_name": "Ole", "orcid": "0000-0001-8670-4575", "clpid": "K\u00f6nig-Ole" }, { "family_name": "Lewin", "given_name": "Collin", "orcid": "0000-0002-8671-1190", "clpid": "Lewin-Collin" }, { "family_name": "Nathan", "given_name": "Edward", "orcid": "0000-0002-9633-9193", "clpid": "Nathan-Edward" }, { "family_name": "Panagiotou", "given_name": "Christos", "clpid": "Panagiotou-Christos" } ], "abstract": "Accreting black holes commonly exhibit hard X-ray emission, originating from a region of hot plasma near the central engine referred to as the corona. The origin and geometry of the corona are poorly understood, and models invoking either inflowing or outflowing material (or both) can successfully explain only parts of the observed phenomenology. In particular, recent works indicate that the time-averaged and variability property might originate in different regions of the corona. In this paper we present a model designed to move beyond the lamppost paradigm, with the goal of accounting for the vertical extent of the corona. In particular, we highlight the impact of including self-consistently a second lamppost, mimicking, for example, an extended jet base. We fully include the effect that the second source has on the time-dependent disk ionization, reflection spectrum, and reverberation lags. We also present an application of this new model to NICER observations of the X-ray binary MAXI J1820+070 near its hard-to-soft state transition. We demonstrate that in these observations, a vertically extended corona can capture both spectral and timing properties, while a single-lamppost model can not. In this scenario, the illumination responsible for the time-averaged spectrum originates close to the black hole, while the variability is likely associated with the ballistic jet.", "doi": "10.3847/1538-4357/acd24f", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2023-07-01", "series_number": "1", "volume": "951", "issue": "1", "pages": "Art. No. 19" }, { "id": "authors:pg73s-3pr42", "collection": "authors", "collection_id": "pg73s-3pr42", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230526-436870000.28", "type": "article", "title": "Simultaneous space and phase resolved X-ray polarimetry of the Crab pulsar and nebula", "author": [ { "family_name": "Bucciantini", "given_name": "Niccol\u00f3", "orcid": "0000-0002-8848-1392", "clpid": "Bucciantini-Niccol\u00f3" }, { "family_name": "Ferrazzoli", "given_name": "Riccardo", "orcid": "0000-0003-1074-8605" }, { "family_name": "Bachetti", "given_name": "Matteo", "orcid": "0000-0002-4576-9337" }, { "family_name": "Rankin", "given_name": "John", "orcid": "0000-0002-9774-0560" }, { "family_name": "Di Lalla", "given_name": "Niccol\u00f3", "orcid": "0000-0002-7574-1298" }, { "family_name": "Sgr\u00f3", "given_name": "Carmelo", "orcid": "0000-0001-5676-6214" }, { "family_name": "Omodei", "given_name": "Nicola", "orcid": "0000-0002-5448-7577" }, { "family_name": "Kitaguchi", "given_name": "Takao" }, { "family_name": "Mizuno", "given_name": "Tsunefumi", "orcid": "0000-0001-7263-0296" }, { "family_name": "Gunji", "given_name": "Shuichi", "orcid": "0000-0002-5881-2445" }, { "family_name": "Watanabe", "given_name": "Eri", "orcid": "0000-0003-0622-8703" }, { "family_name": "Baldini", "given_name": "Luca", "orcid": "0000-0002-9785-7726" }, { "family_name": "Slane", "given_name": "Patrick O.", "orcid": "0000-0002-6986-6756" }, { "family_name": "Weisskopf", "given_name": "Martin C.", "orcid": "0000-0002-5270-4240" }, { "family_name": "Romani", "given_name": "Roger W.", "orcid": "0000-0001-6711-3286" }, { "family_name": "Possenti", "given_name": "Andrea", "orcid": "0000-0001-5902-3731" }, { "family_name": "Marshall", "given_name": "Herman L.", "orcid": "0000-0002-6492-1293" }, { "family_name": "Silvestri", "given_name": "Stefano", "orcid": "0000-0002-8665-0105" }, { "family_name": "Pacciani", "given_name": "Luigi", "orcid": "0000-0001-6897-5996" }, { "family_name": "Negro", "given_name": "Michela", "orcid": "0000-0002-6548-5622" }, { "family_name": "Muleri", "given_name": "Fabio", "orcid": "0000-0003-3331-3794" }, { "family_name": "de O\u00f1a Wilhelmi", "given_name": "Emma", "orcid": "0000-0002-5401-0744" }, { "family_name": "Xie", "given_name": "Fei", "orcid": "0000-0002-0105-5826" }, { "family_name": "Heyl", "given_name": "Jeremy", "orcid": "0000-0001-9739-367X" }, { "family_name": "Pesce-Rollins", "given_name": "Melissa", "orcid": "0000-0003-1790-8018" }, { "family_name": "Wong", "given_name": "Josephine", "orcid": "0000-0001-6395-2066" }, { "family_name": "Pilia", "given_name": "Maura", "orcid": "0000-0001-7397-8091" }, { "family_name": "Agudo", "given_name": "Ivan", "orcid": "0000-0002-3777-6182" }, { "family_name": "Antonelli", "given_name": "Lucio A.", "orcid": "0000-0002-5037-9034" }, { "family_name": "Baumgartner", "given_name": "Wayne H.", "orcid": "0000-0002-5106-0463" }, { "family_name": "Bellazzini", "given_name": "Ronaldo", "orcid": "0000-0002-2469-7063" }, { "family_name": "Bianchi", "given_name": "Stefano", "orcid": "0000-0002-4622-4240" }, { "family_name": "Bongiorno", "given_name": "Stephen D.", "orcid": "0000-0002-0901-2097" }, { "family_name": "Bonino", "given_name": "Raffaella", "orcid": "0000-0002-4264-1215" }, { "family_name": "Brez", "given_name": "Alessandro", "orcid": "0000-0002-9460-1821" }, { "family_name": "Capitanio", "given_name": "Fiamma", "orcid": "0000-0002-6384-3027" }, { "family_name": "Castellano", "given_name": "Simone", "orcid": "0000-0003-1111-4292" }, { "family_name": "Cavazzuti", "given_name": "Elisabetta", "orcid": "0000-0001-7150-9638" }, { "family_name": "Chen", "given_name": "Chien-Ting J.", "orcid": "0000-0002-4945-5079" }, { "family_name": "Ciprini", "given_name": "Stefano", "orcid": "0000-0002-0712-2479" }, { "family_name": "Costa", "given_name": "Enrico", "orcid": "0000-0003-4925-8523" }, { "family_name": "De Rosa", "given_name": "Alessandra", "orcid": "0000-0001-5668-6863" }, { "family_name": "Del Monte", "given_name": "Ettore", "orcid": "0000-0002-3013-6334" }, { "family_name": "Di Gesu", "given_name": "Laura", "orcid": "0000-0002-5614-5028" }, { "family_name": "Di Marco", "given_name": "Alessandro", "orcid": "0000-0003-0331-3259" }, { "family_name": "Donnarumma", "given_name": "Immacolata", "orcid": "0000-0002-4700-4549" }, { "family_name": "Doroshenko", "given_name": "Victor", "orcid": "0000-0001-8162-1105" }, { "family_name": "Dovciak", "given_name": "Michal", "orcid": "0000-0003-0079-1239" }, { "family_name": "Ehlert", "given_name": "Steven R.", "orcid": "0000-0003-4420-2838" }, { "family_name": "Enoto", "given_name": "Teruaki", "orcid": "0000-0003-1244-3100" }, { "family_name": "Evangelista", "given_name": "Yuri", "orcid": "0000-0001-6096-6710" }, { "family_name": "Fabiani", "given_name": "Sergio", "orcid": "0000-0003-1533-0283" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Hayashida", "given_name": "Kiyoshi", "clpid": "Hayashida-Kiyoshi" }, { "family_name": "Iwakiri", "given_name": "Wataru B.", "orcid": "0000-0002-0207-9010" }, { "family_name": "Jorstad", "given_name": "Svetlana G.", "orcid": "0000-0001-6158-1708" }, { "family_name": "Kaaret", "given_name": "Philip E.", "orcid": "0000-0002-3638-0637" }, { "family_name": "Karas", "given_name": "Vladimir", "orcid": "0000-0002-5760-0459" }, { "family_name": "Kislat", "given_name": "Fabian", "orcid": "0000-0001-7477-0380" }, { "family_name": "Kolodziejczak", "given_name": "Jeffery J.", "orcid": "0000-0002-0110-6136" }, { "family_name": "Krawczynski", "given_name": "Henric", "orcid": "0000-0002-1084-6507" }, { "family_name": "La Monaca", "given_name": "Fabio", "orcid": "0000-0001-8916-4156" }, { "family_name": "Latronico", "given_name": "Luca", "orcid": "0000-0002-0984-1856" }, { "family_name": "Liodakis", "given_name": "Ioannis", "orcid": "0000-0001-9200-4006" }, { "family_name": "Maldera", "given_name": "Simone", "orcid": "0000-0002-0698-4421" }, { "family_name": "Manfreda", "given_name": "Alberto", "orcid": "0000-0002-0998-4953" }, { "family_name": "Marin", "given_name": "Fr\u00e9d\u00e9ric", "orcid": "0000-0003-4952-0835" }, { "family_name": "Marinucci", "given_name": "Andrea", "orcid": "0000-0002-2055-4946" }, { "family_name": "Marscher", "given_name": "Alan P.", "orcid": "0000-0001-7396-3332" }, { "family_name": "Massaro", "given_name": "Francesco", "orcid": "0000-0002-1704-9850" }, { "family_name": "Matt", "given_name": "Giorgio", "orcid": "0000-0002-2152-0916" }, { "family_name": "Mitsuishi", "given_name": "Ikuyuki" }, { "family_name": "Ng", "given_name": "C.-Y.", "orcid": "0000-0002-5847-2612" }, { "family_name": "O'Dell", "given_name": "Stephen L.", "orcid": "0000-0002-1868-8056" }, { "family_name": "Oppedisano", "given_name": "Chiara", "orcid": "0000-0001-6194-4601" }, { "family_name": "Papitto", "given_name": "Alessandro", "orcid": "0000-0001-6289-7413" }, { "family_name": "Pavlov", "given_name": "George G.", "orcid": "0000-0002-7481-5259" }, { "family_name": "Peirson", "given_name": "Abel L.", "orcid": "0000-0001-6292-1911" }, { "family_name": "Perri", "given_name": "Matteo", "orcid": "0000-0003-3613-4409" }, { "family_name": "Petrucci", "given_name": "Pierre-Olivier", "orcid": "0000-0001-6061-3480" }, { "family_name": "Poutanen", "given_name": "Juri", "orcid": "0000-0002-0983-0049" }, { "family_name": "Puccetti", "given_name": "Simonetta", "orcid": "0000-0002-2734-7835" }, { "family_name": "Ramsey", "given_name": "Brian D.", "orcid": "0000-0003-1548-1524" }, { "family_name": "Ratheesh", "given_name": "Ajay", "orcid": "0000-0003-0411-4243" }, { "family_name": "Roberts", "given_name": "Oliver J.", "orcid": "0000-0002-7150-9061" }, { "family_name": "Soffitta", "given_name": "Paolo", "orcid": "0000-0002-7781-4104" }, { "family_name": "Spandre", "given_name": "Gloria", "orcid": "0000-0003-0802-3453" }, { "family_name": "Swartz", "given_name": "Doug", "orcid": "0000-0002-2954-4461" }, { "family_name": "Tamagawa", "given_name": "Toru", "orcid": "0000-0002-8801-6263" }, { "family_name": "Tavecchio", "given_name": "Fabrizio", "orcid": "0000-0003-0256-0995" }, { "family_name": "Taverna", "given_name": "Roberto", "orcid": "0000-0002-1768-618X" }, { "family_name": "Tawara", "given_name": "Yuzuru" }, { "family_name": "Tennant", "given_name": "Allyn F.", "orcid": "0000-0002-9443-6774" }, { "family_name": "Thomas", "given_name": "Nicolas E." }, { "family_name": "Tombesi", "given_name": "Francesco", "orcid": "0000-0002-6562-8654" }, { "family_name": "Trois", "given_name": "Alessio", "orcid": "0000-0002-3180-6002" }, { "family_name": "Tsygankov", "given_name": "Sergey S.", "orcid": "0000-0002-9679-0793" }, { "family_name": "Turolla", "given_name": "Roberto", "orcid": "0000-0003-3977-8760" }, { "family_name": "Vink", "given_name": "Jacco", "orcid": "0000-0002-4708-4219" }, { "family_name": "Wu", "given_name": "Kinwah", "orcid": "0000-0002-7568-8765" }, { "family_name": "Zane", "given_name": "Silvia", "orcid": "0000-0001-5326-880X" } ], "abstract": "The Crab pulsar and its nebula are among the most studied astrophysical systems, and constitute one of the most promising environments where high-energy processes and particle acceleration can be investigated. They are the only objects for which significant X-ray polarization was detected in the past. Here we present the Imaging X-ray Polarimetry Explorer (IXPE) observation of the Crab pulsar and nebula. The total pulsar pulsed emission in the [2\u20138]\u2009keV energy range is unpolarized. Significant polarization up to 15% is detected in the core of the main peak. The nebula has a total space integrated polarized degree of 20% and polarization angle of 145\u00b0. The polarized maps show a large variation in the local polarization, and regions with a polarized degree up to 45\u201350%. The polarization pattern suggests a predominantly toroidal magnetic field. Our findings for the pulsar are inconsistent with most inner magnetospheric models, and suggest emission is more likely to come from the wind region. For the nebula, the polarization map suggests a patchy distribution of turbulence, uncorrelated with the intensity, in contrast with simple expectations from numerical models.", "doi": "10.1038/s41550-023-01936-8", "issn": "2397-3366", "publisher": "Nature Publishing Group", "publication": "Nature Astronomy", "publication_date": "2023-05", "series_number": "5", "volume": "7", "issue": "5", "pages": "602-610" }, { "id": "authors:25kzg-ra964", "collection": "authors", "collection_id": "25kzg-ra964", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230523-606156800.6", "type": "article", "title": "IXPE Observations of the Quintessential Wind-accreting X-Ray Pulsar Vela X-1", "author": [ { "family_name": "Forsblom", "given_name": "Sofia V.", "orcid": "0000-0001-9167-2790", "clpid": "Forsblom-Sofia-V" }, { "family_name": "Poutanen", "given_name": "Juri", "orcid": "0000-0002-0983-0049" }, { "family_name": "Tsygankov", "given_name": "Sergey S.", "orcid": "0000-0002-9679-0793" }, { "family_name": "Bachetti", "given_name": "Matteo", "orcid": "0000-0002-4576-9337" }, { "family_name": "Di Marco", "given_name": "Alessandro", "orcid": "0000-0003-0331-3259" }, { "family_name": "Doroshenko", "given_name": "Victor", "orcid": "0000-0001-8162-1105" }, { "family_name": "Heyl", "given_name": "Jeremy", "orcid": "0000-0001-9739-367X" }, { "family_name": "La Monaca", "given_name": "Fabio", "orcid": "0000-0001-8916-4156" }, { "family_name": "Malacaria", "given_name": "Christian", "orcid": "0000-0002-0380-0041" }, { "family_name": "Marshall", "given_name": "Herman L.", "orcid": "0000-0002-6492-1293" }, { "family_name": "Muleri", "given_name": "Fabio", "orcid": "0000-0003-3331-3794" }, { "family_name": "Mushtukov", "given_name": "Alexander A.", "orcid": "0000-0003-2306-419X" }, { "family_name": "Pilia", "given_name": "Maura", "orcid": "0000-0001-7397-8091" }, { "family_name": "Rogantini", "given_name": "Daniele", "orcid": "0000-0002-5359-9497" }, { "family_name": "Suleimanov", "given_name": "Valery F.", "orcid": "0000-0003-3733-7267" }, { "family_name": "Taverna", "given_name": "Roberto", "orcid": "0000-0002-1768-618X" }, { "family_name": "Xie", "given_name": "Fei", "orcid": "0000-0002-0105-5826" }, { "family_name": "Agudo", "given_name": "Iv\u00e1n", "orcid": "0000-0002-3777-6182" }, { "family_name": "Antonelli", "given_name": "Lucio A.", "orcid": "0000-0002-5037-9034" }, { "family_name": "Baldini", "given_name": "Luca", "orcid": "0000-0002-9785-7726" }, { "family_name": "Baumgartner", "given_name": "Wayne H.", "orcid": "0000-0002-5106-0463" }, { "family_name": "Bellazzini", "given_name": "Ronaldo", "orcid": "0000-0002-2469-7063" }, { "family_name": "Bianchi", "given_name": "Stefano", "orcid": "0000-0002-4622-4240" }, { "family_name": "Bongiorno", "given_name": "Stephen D.", "orcid": "0000-0002-0901-2097" }, { "family_name": "Bonino", "given_name": "Raffaella", "orcid": "0000-0002-4264-1215" }, { "family_name": "Brez", "given_name": "Alessandro", "orcid": "0000-0002-9460-1821" }, { "family_name": "Bucciantini", "given_name": "Niccol\u00f2", "orcid": "0000-0002-8848-1392" }, { "family_name": "Capitanio", "given_name": "Fiamma", "orcid": "0000-0002-6384-3027" }, { "family_name": "Castellano", "given_name": "Simone", "orcid": "0000-0003-1111-4292" }, { "family_name": "Cavazzuti", "given_name": "Elisabetta", "orcid": "0000-0001-7150-9638" }, { "family_name": "Chen", "given_name": "Chien-Ting", "orcid": "0000-0002-4945-5079" }, { "family_name": "Ciprini", "given_name": "Stefano", "orcid": "0000-0002-0712-2479" }, { "family_name": "Costa", "given_name": "Enrico", "orcid": "0000-0003-4925-8523" }, { "family_name": "De Rosa", "given_name": "Alessandra", "orcid": "0000-0001-5668-6863" }, { "family_name": "Del Monte", "given_name": "Ettore", "orcid": "0000-0002-3013-6334" }, { "family_name": "Di Gesu", "given_name": "Laura", "orcid": "0000-0002-5614-5028" }, { "family_name": "Di Lalla", "given_name": "Niccol\u00f2", "orcid": "0000-0002-7574-1298" }, { "family_name": "Donnarumma", "given_name": "Immacolata", "orcid": "0000-0002-4700-4549" }, { "family_name": "Dov\u010diak", "given_name": "Michal", "orcid": "0000-0003-0079-1239" }, { "family_name": "Ehlert", "given_name": "Steven R.", "orcid": "0000-0003-4420-2838" }, { "family_name": "Enoto", "given_name": "Teruaki", "orcid": "0000-0003-1244-3100" }, { "family_name": "Evangelista", "given_name": "Yuri", "orcid": "0000-0001-6096-6710" }, { "family_name": "Fabiani", "given_name": "Sergio", "orcid": "0000-0003-1533-0283" }, { "family_name": "Ferrazzoli", "given_name": "Riccardo", "orcid": "0000-0003-1074-8605" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Gunji", "given_name": "Shuichi", "orcid": "0000-0002-5881-2445" }, { "family_name": "Hayashida", "given_name": "Kiyoshi", "orcid": "0000-0002-0110-6136" }, { "family_name": "Iwakiri", "given_name": "Wataru", "orcid": "0000-0002-0207-9010" }, { "family_name": "Jorstad", "given_name": "Svetlana G.", "orcid": "0000-0001-6158-1708" }, { "family_name": "Kaaret", "given_name": "Philip", "orcid": "0000-0002-3638-0637" }, { "family_name": "Karas", "given_name": "Vladimir", "orcid": "0000-0002-5760-0459" }, { "family_name": "Kitaguchi", "given_name": "Takao" }, { "family_name": "Krawczynski", "given_name": "Henric", "orcid": "0000-0002-1084-6507" }, { "family_name": "Latronico", "given_name": "Luca", "orcid": "0000-0002-0984-1856" }, { "family_name": "Liodakis", "given_name": "Ioannis", "orcid": "0000-0001-9200-4006" }, { "family_name": "Maldera", "given_name": "Simone", "orcid": "0000-0002-0698-4421" }, { "family_name": "Manfreda", "given_name": "Alberto", "orcid": "0000-0002-0998-4953" }, { "family_name": "Marin", "given_name": "Fr\u00e9d\u00e9ric", "orcid": "0000-0003-4952-0835" }, { "family_name": "Marinucci", "given_name": "Andrea", "orcid": "0000-0002-2055-4946" }, { "family_name": "Marscher", "given_name": "Alan P.", "orcid": "0000-0001-7396-3332" }, { "family_name": "Matt", "given_name": "Giorgio", "orcid": "0000-0002-2152-0916" }, { "family_name": "Mitsuishi", "given_name": "Ikuyuki" }, { "family_name": "Mizuno", "given_name": "Tsunefumi", "orcid": "0000-0001-7263-0296" }, { "family_name": "Negro", "given_name": "Michela", "orcid": "0000-0002-6548-5622" }, { "family_name": "Ng", "given_name": "Chi-Yung", "orcid": "0000-0002-5847-2612" }, { "family_name": "O'Dell", "given_name": "Stephen L.", "orcid": "0000-0002-1868-8056" }, { "family_name": "Omodei", "given_name": "Nicola", "orcid": "0000-0002-5448-7577" }, { "family_name": "Oppedisano", "given_name": "Chiara", "orcid": "0000-0001-6194-4601" }, { "family_name": "Papitto", "given_name": "Alessandro", "orcid": "0000-0001-6289-7413" }, { "family_name": "Pavlov", "given_name": "George G.", "orcid": "0000-0002-7481-5259" }, { "family_name": "Peirson", "given_name": "Abel L.", "orcid": "0000-0001-6292-1911" }, { "family_name": "Perri", "given_name": "Matteo", "orcid": "0000-0003-3613-4409" }, { "family_name": "Pesce-Rollins", "given_name": "Melissa", "orcid": "0000-0003-1790-8018" }, { "family_name": "Petrucci", "given_name": "Pierre-Olivier", "orcid": "0000-0001-6061-3480" }, { "family_name": "Possenti", "given_name": "Andrea", "orcid": "0000-0001-5902-3731" }, { "family_name": "Puccetti", "given_name": "Simonetta", "orcid": "0000-0002-2734-7835" }, { "family_name": "Ramsey", "given_name": "Brian D.", "orcid": "0000-0003-1548-1524" }, { "family_name": "Rankin", "given_name": "John", "orcid": "0000-0002-9774-0560" }, { "family_name": "Ratheesh", "given_name": "Ajay", "orcid": "0000-0003-0411-4243" }, { "family_name": "Roberts", "given_name": "Oliver J.", "orcid": "0000-0002-7150-9061" }, { "family_name": "Romani", "given_name": "Roger W.", "orcid": "0000-0001-6711-3286" }, { "family_name": "Sgr\u00f2", "given_name": "Carmelo", "orcid": "0000-0001-5676-6214" }, { "family_name": "Slane", "given_name": "Patrick", "orcid": "0000-0002-6986-6756" }, { "family_name": "Soffitta", "given_name": "Paolo", "orcid": "0000-0002-7781-4104" }, { "family_name": "Spandre", "given_name": "Gloria", "orcid": "0000-0003-0802-3453" }, { "family_name": "Sunyaev", "given_name": "Rashid A.", "orcid": "0000-0002-2764-7192" }, { "family_name": "Swartz", "given_name": "Douglas A.", "orcid": "0000-0002-2954-4461" }, { "family_name": "Tamagawa", "given_name": "Toru", "orcid": "0000-0002-8801-6263" }, { "family_name": "Tavecchio", "given_name": "Fabrizio", "orcid": "0000-0003-0256-0995" }, { "family_name": "Tawara", "given_name": "Yuzuru" }, { "family_name": "Tennant", "given_name": "Allyn F.", "orcid": "0000-0002-9443-6774" }, { "family_name": "Thomas", "given_name": "Nicholas E.", "orcid": "0000-0003-0411-4606" }, { "family_name": "Tombesi", "given_name": "Francesco", "orcid": "0000-0002-6562-8654" }, { "family_name": "Trois", "given_name": "Alessio", "orcid": "0000-0002-3180-6002" }, { "family_name": "Turolla", "given_name": "Roberto", "orcid": "0000-0003-3977-8760" }, { "family_name": "Vink", "given_name": "Jacco", "orcid": "0000-0002-4708-4219" }, { "family_name": "Weisskopf", "given_name": "Martin C.", "orcid": "0000-0002-5270-4240" }, { "family_name": "Wu", "given_name": "Kinwah", "orcid": "0000-0002-7568-8765" }, { "family_name": "Zane", "given_name": "Silvia", "orcid": "0000-0001-5326-880X" }, { "literal": "IXPE Collaboration" } ], "abstract": "The radiation from accreting X-ray pulsars was expected to be highly polarized, with some estimates for the polarization degree of up to 80%. However, phase-resolved and energy-resolved polarimetry of X-ray pulsars is required in order to test different models and to shed light on the emission processes and the geometry of the emission region. Here we present the first results of the observations of the accreting X-ray pulsar Vela X-1 performed with the Imaging X-ray Polarimetry Explorer. Vela X-1 is considered to be the archetypal example of a wind-accreting, high-mass X-ray binary system, consisting of a highly magnetized neutron star accreting matter from its supergiant stellar companion. The spectropolarimetric analysis of the phase-averaged data for Vela X-1 reveals a polarization degree (PD) of 2.3% \u00b1 0.4% at the polarization angle (PA) of \u221247.\u00b03 \u00b1 5.\u00b04. A low PD is consistent with the results obtained for other X-ray pulsars and is likely related to the inverse temperature structure of the neutron star atmosphere. The energy-resolved analysis shows the PD above 5 keV reaching 6%\u201310% and a \u223c90\u00b0 difference in the PA compared to the data in the 2\u20133 keV range. The phase-resolved spectropolarimetric analysis finds a PD in the range 0%\u20139% with the PA varying between \u221280\u00b0 and 40\u00b0.", "doi": "10.3847/2041-8213/acc391", "issn": "2041-8205", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal Letters", "publication_date": "2023-04-20", "series_number": "2", "volume": "947", "issue": "2", "pages": "Art. No. L20" }, { "id": "authors:sbjtv-32060", "collection": "authors", "collection_id": "sbjtv-32060", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230328-707475900.56", "type": "article", "title": "X-Ray Polarimetry Reveals the Magnetic-field Topology on Sub-parsec Scales in Tycho's Supernova Remnant", "author": [ { "family_name": "Ferrazzoli", "given_name": "Riccardo", "orcid": "0000-0003-1074-8605", "clpid": "Ferrazzoli-Riccardo" }, { "family_name": "Slane", "given_name": "Patrick", "orcid": "0000-0002-6986-6756" }, { "family_name": "Prokhorov", "given_name": "Dmitry" }, { "family_name": "Zhou", "given_name": "Ping", "orcid": "0000-0002-5683-822X" }, { "family_name": "Vink", "given_name": "Jacco", "orcid": "0000-0002-4708-4219" }, { "family_name": "Bucciantini", "given_name": "Niccol\u00f2", "orcid": "0000-0002-8848-1392" }, { "family_name": "Costa", "given_name": "Enrico", "orcid": "0000-0003-4925-8523" }, { "family_name": "Di Lalla", "given_name": "Niccol\u00f2", "orcid": "0000-0002-7574-1298" }, { "family_name": "Di Marco", "given_name": "Alessandro", "orcid": "0000-0003-0331-3259" }, { "family_name": "Soffitta", "given_name": "Paolo", "orcid": "0000-0002-7781-4104" }, { "family_name": "Weisskopf", "given_name": "Martin C.", "orcid": "0000-0002-5270-4240" }, { "family_name": "Asakura", "given_name": "Kazunori" }, { "family_name": "Baldini", "given_name": "Luca", "orcid": "0000-0002-9785-7726" }, { "family_name": "Heyl", "given_name": "Jeremy", "orcid": "0000-0001-9739-367X" }, { "family_name": "Kaaret", "given_name": "Philip E.", "orcid": "0000-0002-3638-0637" }, { "family_name": "Marin", "given_name": "Fr\u00e9d\u00e9ric", "orcid": "0000-0003-4952-0835" }, { "family_name": "Mizuno", "given_name": "Tsunefumi", "orcid": "0000-0001-7263-0296" }, { "family_name": "Ng", "given_name": "C.-Y.", "orcid": "0000-0002-5847-2612" }, { "family_name": "Pesce-Rollins", "given_name": "Melissa", "orcid": "0000-0003-1790-8018" }, { "family_name": "Silvestri", "given_name": "Stefano", "orcid": "0000-0002-6125-5424" }, { "family_name": "Sgr\u00f2", "given_name": "Carmelo", "orcid": "0000-0001-5676-6214" }, { "family_name": "Swartz", "given_name": "Douglas A.", "orcid": "0000-0002-2954-4461" }, { "family_name": "Tamagawa", "given_name": "Toru", "orcid": "0000-0002-8801-6263" }, { "family_name": "Yang", "given_name": "Yi-Jung", "orcid": "0000-0001-9108-573X" }, { "family_name": "Agudo", "given_name": "Iv\u00e1n", "orcid": "0000-0002-3777-6182" }, { "family_name": "Antonelli", "given_name": "Lucio A.", "orcid": "0000-0002-5037-9034" }, { "family_name": "Bachetti", "given_name": "Matteo", "orcid": "0000-0002-4576-9337" }, { "family_name": "Baumgartner", "given_name": "Wayne H.", "orcid": "0000-0002-5106-0463" }, { "family_name": "Bellazzini", "given_name": "Ronaldo", "orcid": "0000-0002-2469-7063" }, { "family_name": "Bianchi", "given_name": "Stefano", "orcid": "0000-0002-4622-4240" }, { "family_name": "Bongiorno", "given_name": "Stephen D.", "orcid": "0000-0002-0901-2097" }, { "family_name": "Bonino", "given_name": "Raffaella", "orcid": "0000-0002-4264-1215" }, { "family_name": "Brez", "given_name": "Alessandro", "orcid": "0000-0002-9460-1821" }, { "family_name": "Capitanio", "given_name": "Fiamma", "orcid": "0000-0002-6384-3027" }, { "family_name": "Castellano", "given_name": "Simone", "orcid": "0000-0003-1111-4292" }, { "family_name": "Cavazzuti", "given_name": "Elisabetta", "orcid": "0000-0001-7150-9638" }, { "family_name": "Chen", "given_name": "Chien-Ting", "orcid": "0000-0002-4945-5079" }, { "family_name": "Ciprini", "given_name": "Stefano", "orcid": "0000-0002-0712-2479" }, { "family_name": "De Rosa", "given_name": "Alessandra", "orcid": "0000-0001-5668-6863" }, { "family_name": "Del Monte", "given_name": "Ettore", "orcid": "0000-0002-3013-6334" }, { "family_name": "Di Gesu", "given_name": "Laura", "orcid": "0000-0002-5614-5028" }, { "family_name": "Donnarumma", "given_name": "Immacolata", "orcid": "0000-0002-4700-4549" }, { "family_name": "Doroshenko", "given_name": "Victor", "orcid": "0000-0001-8162-1105" }, { "family_name": "Dov\u010diak", "given_name": "Michal", "orcid": "0000-0003-0079-1239" }, { "family_name": "Ehlert", "given_name": "Steven R.", "orcid": "0000-0003-4420-2838" }, { "family_name": "Enoto", "given_name": "Teruaki", "orcid": "0000-0003-1244-3100" }, { "family_name": "Evangelista", "given_name": "Yuri", "orcid": "0000-0001-6096-6710" }, { "family_name": "Fabiani", "given_name": "Sergio", "orcid": "0000-0003-1533-0283" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Gunji", "given_name": "Shuichi", "orcid": "0000-0002-5881-2445" }, { "family_name": "Hayashida", "given_name": "Kiyoshi" }, { "family_name": "Iwakiri", "given_name": "Wataru", "orcid": "0000-0002-0207-9010" }, { "family_name": "Jorstad", "given_name": "Svetlana G.", "orcid": "0000-0001-6158-1708" }, { "family_name": "Kislat", "given_name": "Fabian", "orcid": "0000-0001-7477-0380" }, { "family_name": "Karas", "given_name": "Vladimir", "orcid": "0000-0002-5760-0459" }, { "family_name": "Kitaguchi", "given_name": "Takao" }, { "family_name": "Kolodziejczak", "given_name": "Jeffery J.", "orcid": "0000-0002-0110-6136" }, { "family_name": "Krawczynski", "given_name": "Henric", "orcid": "0000-0002-1084-6507" }, { "family_name": "La Monaca", "given_name": "Fabio", "orcid": "0000-0001-8916-4156" }, { "family_name": "Latronico", "given_name": "Luca", "orcid": "0000-0002-0984-1856" }, { "family_name": "Liodakis", "given_name": "Ioannis", "orcid": "0000-0001-9200-4006" }, { "family_name": "Maldera", "given_name": "Simone", "orcid": "0000-0002-0698-4421" }, { "family_name": "Manfreda", "given_name": "Alberto", "orcid": "0000-0002-0998-4953" }, { "family_name": "Marinucci", "given_name": "Andrea", "orcid": "0000-0002-2055-4946" }, { "family_name": "Marscher", "given_name": "Alan P.", "orcid": "0000-0001-7396-3332" }, { "family_name": "Marshall", "given_name": "Herman L.", "orcid": "0000-0002-6492-1293" }, { "family_name": "Matt", "given_name": "Giorgio", "orcid": "0000-0002-2152-0916" }, { "family_name": "Mitsuishi", "given_name": "Ikuyuki" }, { "family_name": "Muleri", "given_name": "Fabio", "orcid": "0000-0003-3331-3794" }, { "family_name": "Negro", "given_name": "Michela", "orcid": "0000-0002-6548-5622" }, { "family_name": "O'Dell", "given_name": "Stephen L.", "orcid": "0000-0002-1868-8056" }, { "family_name": "Omodei", "given_name": "Nicola", "orcid": "0000-0002-5448-7577" }, { "family_name": "Oppedisano", "given_name": "Chiara", "orcid": "0000-0001-6194-4601" }, { "family_name": "Papitto", "given_name": "Alessandro", "orcid": "0000-0001-6289-7413" }, { "family_name": "Pavlov", "given_name": "George G.", "orcid": "0000-0002-7481-5259" }, { "family_name": "Peirson", "given_name": "Abel L.", "orcid": "0000-0001-6292-1911" }, { "family_name": "Perri", "given_name": "Matteo", "orcid": "0000-0003-3613-4409" }, { "family_name": "Petrucci", "given_name": "Pierre-Olivier", "orcid": "0000-0001-6061-3480" }, { "family_name": "Pilia", "given_name": "Maura", "orcid": "0000-0001-7397-8091" }, { "family_name": "Possenti", "given_name": "Andrea", "orcid": "0000-0001-5902-3731" }, { "family_name": "Poutanen", "given_name": "Juri", "orcid": "0000-0002-0983-0049" }, { "family_name": "Puccetti", "given_name": "Simonetta", "orcid": "0000-0002-2734-7835" }, { "family_name": "Ramsey", "given_name": "Brian D.", "orcid": "0000-0003-1548-1524" }, { "family_name": "Rankin", "given_name": "John", "orcid": "0000-0002-9774-0560" }, { "family_name": "Ratheesh", "given_name": "Ajay", "orcid": "0000-0003-0411-4243" }, { "family_name": "Roberts", "given_name": "Oliver", "orcid": "0000-0002-7150-9061" }, { "family_name": "Romani", "given_name": "Roger W.", "orcid": "0000-0001-6711-3286" }, { "family_name": "Spandre", "given_name": "Gloria", "orcid": "0000-0003-0802-3453" }, { "family_name": "Tavecchio", "given_name": "Fabrizio", "orcid": "0000-0003-0256-0995" }, { "family_name": "Taverna", "given_name": "Roberto", "orcid": "0000-0002-1768-618X" }, { "family_name": "Tawara", "given_name": "Yuzuru" }, { "family_name": "Tennant", "given_name": "Allyn F.", "orcid": "0000-0002-9443-6774" }, { "family_name": "Thomas", "given_name": "Nicholas E.", "orcid": "0000-0003-0411-4606" }, { "family_name": "Tombesi", "given_name": "Francesco", "orcid": "0000-0002-6562-8654" }, { "family_name": "Trois", "given_name": "Alessio", "orcid": "0000-0002-3180-6002" }, { "family_name": "Tsygankov", "given_name": "Sergey S.", "orcid": "0000-0002-9679-0793" }, { "family_name": "Turolla", "given_name": "Roberto", "orcid": "0000-0003-3977-8760" }, { "family_name": "Wu", "given_name": "Kinwah", "orcid": "0000-0002-7568-8765" }, { "family_name": "Xie", "given_name": "Fei", "orcid": "0000-0002-0105-5826" }, { "family_name": "Zane", "given_name": "Silvia", "orcid": "0000-0001-5326-880X" } ], "abstract": "Supernova remnants are commonly considered to produce most of the Galactic cosmic rays via diffusive shock acceleration. However, many questions regarding the physical conditions at shock fronts, such as the magnetic-field morphology close to the particle acceleration sites, remain open. Here we report the detection of a localized polarization signal from some synchrotron X-ray emitting regions of Tycho's supernova remnant made by the Imaging X-ray Polarimetry Explorer. The derived degree of polarization of the X-ray synchrotron emission is 9% \u00b1 2% averaged over the whole remnant, and 12% \u00b1 2% at the rim, higher than the value of polarization of 7%\u20138% observed in the radio band. In the west region, the degree of polarization is 23% \u00b1 4%. The degree of X-ray polarization in Tycho is higher than for Cassiopeia A, suggesting a more ordered magnetic field or a larger maximum turbulence scale. The measured tangential direction of polarization corresponds to the radial magnetic field, and is consistent with that observed in the radio band. These results are compatible with the expectation of turbulence produced by an anisotropic cascade of a radial magnetic field near the shock, where we derive a magnetic-field amplification factor of 3.4 \u00b1 0.3. The fact that this value is significantly smaller than those expected from acceleration models is indicative of highly anisotropic magnetic-field turbulence, or that the emitting electrons either favor regions of lower turbulence, or accumulate close to where the orientation of the magnetic field is preferentially radially oriented due to hydrodynamical instabilities.", "doi": "10.3847/1538-4357/acb496", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2023-03-01", "series_number": "1", "volume": "945", "issue": "1", "pages": "Art. No. 52" }, { "id": "authors:ftf6k-yf875", "collection": "authors", "collection_id": "ftf6k-yf875", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230615-813038000.39", "type": "article", "title": "The IXPE View of GRB 221009A", "author": [ { "family_name": "Negro", "given_name": "Michela", "orcid": "0000-0002-6548-5622", "clpid": "Negro-Michela" }, { "family_name": "Di Lalla", "given_name": "Niccol\u00f3", "orcid": "0000-0002-7574-1298", "clpid": "Di-Lalla-Niccol\u00f3" }, { "family_name": "Omodei", "given_name": "Nicola", "orcid": "0000-0002-5448-7577", "clpid": "Omodei-Nicola" }, { "family_name": "Veres", "given_name": "Peter", "orcid": "0000-0002-2149-9846", "clpid": "Veres-Peter" }, { "family_name": "Silvestri", "given_name": "Stefano", "orcid": "0000-0002-8665-0105", "clpid": "Silvestri-Stefano" }, { "family_name": "Manfreda", "given_name": "Alberto", "orcid": "0000-0002-0998-4953", "clpid": "Manfreda-Alberto" }, { "family_name": "Burns", "given_name": "Eric", "orcid": "0000-0002-2942-3379", "clpid": "Burns-Eric" }, { "family_name": "Baldini", "given_name": "Luca", "orcid": "0000-0002-9785-7726", "clpid": "Baldini-Luca" }, { "family_name": "Costa", "given_name": "Enrico", "orcid": "0000-0003-4925-8523", "clpid": "Costa-Enrico" }, { "family_name": "Ehlert", "given_name": "Steven R.", "orcid": "0000-0003-4420-2838", "clpid": "Ehlert-Steven-R" }, { "family_name": "Kennea", "given_name": "Jamie A.", "orcid": "0000-0002-6745-4790", "clpid": "Kennea-Jamie-A" }, { "family_name": "Liodakis", "given_name": "Ioannis", "orcid": "0000-0001-9200-4006", "clpid": "Liodakis-Ioannis" }, { "family_name": "Marshall", "given_name": "Herman L.", "orcid": "0000-0002-6492-1293", "clpid": "Marshall-Herman-L" }, { "family_name": "Mereghetti", "given_name": "Sandro", "orcid": "0000-0003-3259-7801", "clpid": "Mereghetti-Sandro" }, { "family_name": "Middei", "given_name": "Riccardo", "orcid": "0000-0001-9815-9092", "clpid": "Middei-Riccardo" }, { "family_name": "Muleri", "given_name": "Fabio", "orcid": "0000-0003-3331-3794", "clpid": "Muleri-Fabio" }, { "family_name": "O'Dell", "given_name": "Stephen L.", "orcid": "0000-0002-1868-8056", "clpid": "O'Dell-Stephen-L" }, { "family_name": "Roberts", "given_name": "Oliver J.", "orcid": "0000-0002-7150-9061", "clpid": "Roberts-Oliver-J" }, { "family_name": "Romani", "given_name": "Roger W.", "orcid": "0000-0001-6711-3286", "clpid": "Romani-Roger-W" }, { "family_name": "Sgr\u00f3", "given_name": "Carmelo", "orcid": "0000-0001-5676-6214", "clpid": "Sgr\u00f3-Carmelo" }, { "family_name": "Terashima", "given_name": "Masanobu", "orcid": "0000-0002-9477-6621", "clpid": "Terashima-Masanobu" }, { "family_name": "Tiengo", "given_name": "Andrea", "orcid": "0000-0002-6038-1090", "clpid": "Tiengo-Andrea" }, { "family_name": "Viscolo", "given_name": "Domenico", "orcid": "0000-0002-7076-9929", "clpid": "Viscolo-Domenico" }, { "family_name": "Di Marco", "given_name": "Alessandro", "orcid": "0000-0003-0331-3259", "clpid": "Di-Marco-Alessandro" }, { "family_name": "La Monaca", "given_name": "Fabio", "orcid": "0000-0001-8916-4156", "clpid": "La-Monaca-Fabio" }, { "family_name": "Latronico", "given_name": "Luca", "orcid": "0000-0002-0984-1856", "clpid": "Latronico-Luca" }, { "family_name": "Matt", "given_name": "Giorgio", "orcid": "0000-0002-2152-0916", "clpid": "Matt-Giorgio" }, { "family_name": "Perri", "given_name": "Matteo", "orcid": "0000-0003-3613-4409", "clpid": "Perri-Matteo" }, { "family_name": "Puccetti", "given_name": "Simonetta", "orcid": "0000-0002-2734-7835", "clpid": "Puccetti-Simonetta" }, { "family_name": "Poutanen", "given_name": "Juri", "orcid": "0000-0002-0983-0049", "clpid": "Poutanen-Juri" }, { "family_name": "Ratheesh", "given_name": "Ajay", "orcid": "0000-0003-0411-4243", "clpid": "Ratheesh-Ajay" }, { "family_name": "Rogantini", "given_name": "Daniele", "orcid": "0000-0002-5359-9497", "clpid": "Rogantini-Daniele" }, { "family_name": "Slane", "given_name": "Patrick", "orcid": "0000-0002-6986-6756", "clpid": "Slane-Patrick" }, { "family_name": "Soffitta", "given_name": "Paolo", "orcid": "0000-0002-7781-4104", "clpid": "Soffitta-Paolo" }, { "family_name": "Lindfors", "given_name": "Elina", "orcid": "0000-0002-9155-6199", "clpid": "Lindfors-Elina" }, { "family_name": "Nilsson", "given_name": "Kari", "orcid": "0000-0002-1445-8683", "clpid": "Nilsson-Kari" }, { "family_name": "Kasikov", "given_name": "Anni", "orcid": "0000-0002-1823-3975", "clpid": "Kasikov-Anni" }, { "family_name": "Marscher", "given_name": "Alan P.", "orcid": "0000-0001-7396-3332", "clpid": "Marscher-Alan-P" }, { "family_name": "Tavecchio", "given_name": "Fabrizio", "orcid": "0000-0003-0256-0995", "clpid": "Tavecchio-Fabrizio" }, { "family_name": "Cibrario", "given_name": "Nicol\u00f3", "orcid": "0000-0003-3842-4493", "clpid": "Cibrario-Nicol\u00f3" }, { "family_name": "Gunji", "given_name": "Shuichi", "orcid": "0000-0002-5881-2445", "clpid": "Gunji-Shuichi" }, { "family_name": "Malacaria", "given_name": "Christian", "orcid": "0000-0002-0380-0041", "clpid": "Malacaria-Christian" }, { "family_name": "Paggi", "given_name": "Alessandro", "orcid": "0000-0002-5646-2410", "clpid": "Paggi-Alessandro" }, { "family_name": "Yang", "given_name": "Yi-Jung", "orcid": "0000-0001-9108-573X", "clpid": "Yang-Yi-Jung" }, { "family_name": "Zane", "given_name": "Silvia", "orcid": "0000-0001-5326-880X", "clpid": "Zane-Silvia" }, { "family_name": "Weisskopf", "given_name": "Martin C.", "orcid": "0000-0002-5270-4240", "clpid": "Weisskopf-Martin-C" }, { "family_name": "Agudo", "given_name": "Ivan", "orcid": "0000-0002-3777-6182", "clpid": "Agudo-Iv\u00e1n" }, { "family_name": "Antonelli", "given_name": "Lucio A.", "orcid": "0000-0002-5037-9034", "clpid": "Antonelli-Lucio-A" }, { "family_name": "Bachetti", "given_name": "Matteo", "orcid": "0000-0002-4576-9337", "clpid": "Bachetti-Matteo" }, { "family_name": "Baumgartner", "given_name": "Wayne H.", "orcid": "0000-0002-5106-0463", "clpid": "Baumgartner-Wayne-H" }, { "family_name": "Bellazzini", "given_name": "Ronaldo", "orcid": "0000-0002-2469-7063", "clpid": "Bellazzini-Ronaldo" }, { "family_name": "Bianchi", "given_name": "Stefano", "orcid": "0000-0002-4622-4240", "clpid": "Bianchi-Stefano" }, { "family_name": "Bongiorno", "given_name": "Stephen D.", "orcid": "0000-0002-0901-2097", "clpid": "Bongiorno-Stephen-D" }, { "family_name": "Bonino", "given_name": "Raffaella", "orcid": "0000-0002-4264-1215", "clpid": "Bonino-Raffaella" }, { "family_name": "Brez", "given_name": "Alessandro", "orcid": "0000-0002-9460-1821", "clpid": "Brez-Alessandro" }, { "family_name": "Bucciantini", "given_name": "Niccol\u00f3", "orcid": "0000-0002-8848-1392", "clpid": "Bucciantini-Niccol\u00f3" }, { "family_name": "Capitanio", "given_name": "Fiamma", "orcid": "0000-0002-6384-3027", "clpid": "Capitanio-Fiamma" }, { "family_name": "Castellano", "given_name": "Simone", "orcid": "0000-0003-1111-4292", "clpid": "Castellano-Simone" }, { "family_name": "Cavazzuti", "given_name": "Elisabetta", "orcid": "0000-0001-7150-9638", "clpid": "Cavazzuti-Elisabetta" }, { "family_name": "Chen", "given_name": "Chien-Ting J.", "orcid": "0000-0002-4945-5079", "clpid": "Chen-Chien-Ting-J" }, { "family_name": "Ciprini", "given_name": "Stefano", "orcid": "0000-0002-0712-2479", "clpid": "Ciprini-Stefano" }, { "family_name": "De Rosa", "given_name": "Alessandra", "orcid": "0000-0001-5668-6863", "clpid": "De-Rosa-Alessandra" }, { "family_name": "Del Monte", "given_name": "Ettore", "orcid": "0000-0002-3013-6334", "clpid": "Del-Monte-Ettore" }, { "family_name": "Di Gesu", "given_name": "Laura", "orcid": "0000-0002-5614-5028", "clpid": "Di-Gesu-Laura" }, { "family_name": "Donnarumma", "given_name": "Immacolata", "orcid": "0000-0002-4700-4549", "clpid": "Donnarumma-Immacolata" }, { "family_name": "Doroshenko", "given_name": "Victor", "orcid": "0000-0001-8162-1105", "clpid": "Doroshenko-Victor" }, { "family_name": "Dovc\u0306iak", "given_name": "Michal", "orcid": "0000-0003-0079-1239", "clpid": "Dovc\u0306iak-Michal" }, { "family_name": "Enoto", "given_name": "Teruaki", "orcid": "0000-0003-1244-3100", "clpid": "Enoto-Teruaki" }, { "family_name": "Evangelista", "given_name": "Yuri", "orcid": "0000-0001-6096-6710", "clpid": "Evangelista-Yuri" }, { "family_name": "Fabiani", "given_name": "Sergio", "orcid": "0000-0003-1533-0283", "clpid": "Fabiani-Sergio" }, { "family_name": "Ferrazzoli", "given_name": "Riccardo", "orcid": "0000-0003-1074-8605", "clpid": "Ferrazzoli-Riccardo" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Hayashida", "given_name": "Kiyoshi", "orcid": "0000-0002-0110-6136", "clpid": "Hayashida-Kiyoshi" }, { "family_name": "Heyl", "given_name": "Jeremy", "orcid": "0000-0001-9739-367X", "clpid": "Heyl-Jeremy" }, { "family_name": "Iwakiri", "given_name": "Wataru B.", "orcid": "0000-0002-0207-9010", "clpid": "Iwakiri-Wataru-B" }, { "family_name": "Jorstad", "given_name": "Svetlana G.", "orcid": "0000-0001-9522-5453", "clpid": "Jorstad-Svetlana-G" }, { "family_name": "Kaaret", "given_name": "Philip", "orcid": "0000-0002-3638-0637", "clpid": "Kaaret-Philip" }, { "family_name": "Karas", "given_name": "Vladimir", "orcid": "0000-0002-5760-0459", "clpid": "Karas-Vladimir" }, { "family_name": "Kislat", "given_name": "Fabian", "orcid": "0000-0001-7477-0380", "clpid": "Kislat-Fabian" }, { "family_name": "Kitaguchi", "given_name": "Takao", "clpid": "Kitaguchi-Takao" }, { "family_name": "Krawczynski", "given_name": "Henric", "orcid": "0000-0002-1084-6507", "clpid": "Krawczynski-Henric" }, { "family_name": "Maldera", "given_name": "Simone", "orcid": "0000-0002-0698-4421", "clpid": "Maldera-Simone" }, { "family_name": "Marin", "given_name": "Fr\u00e9d\u00e9ric", "orcid": "0000-0003-4952-0835", "clpid": "Marin-Fr\u00e9d\u00e9ric" }, { "family_name": "Marinucci", "given_name": "Andrea", "orcid": "0000-0002-2055-4946", "clpid": "Marinucci-Andrea" }, { "family_name": "Mitsuishi", "given_name": "Ikuyuki", "clpid": "Mitsuishi-Ikuyuki" }, { "family_name": "Mizuno", "given_name": "Tsunefumi", "orcid": "0000-0001-7263-0296", "clpid": "Mizuno-Tsunefumi" }, { "family_name": "Ng", "given_name": "C.-Y.", "orcid": "0000-0002-5847-2612", "clpid": "Ng-Stephen-Chi-Yung" }, { "family_name": "Oppedisano", "given_name": "Chiara", "orcid": "0000-0001-6194-4601", "clpid": "Oppedisano-Chiara" }, { "family_name": "Papitto", "given_name": "Alessandro", "orcid": "0000-0001-6289-7413", "clpid": "Papitto-Alessandro" }, { "family_name": "Pavlov", "given_name": "George G.", "orcid": "0000-0002-7481-5259", "clpid": "Pavlov-George-G" }, { "family_name": "Peirson", "given_name": "Abel L.", "orcid": "0000-0001-6292-1911", "clpid": "Peirson-Abel-L" }, { "family_name": "Pesce-Rollins", "given_name": "Melissa", "orcid": "0000-0003-1790-8018", "clpid": "Pesce-Rollins-Melissa" }, { "family_name": "Petrucci", "given_name": "Pierre-Olivier", "orcid": "0000-0001-6061-3480", "clpid": "Petrucci-Pierre-Olivier" }, { "family_name": "Pilia", "given_name": "Maura", "orcid": "0000-0001-7397-8091", "clpid": "Pilla-Maura" }, { "family_name": "Possenti", "given_name": "Andrea", "orcid": "0000-0001-5902-3731", "clpid": "Possenti-Andrea" }, { "family_name": "Ramsey", "given_name": "Brian D.", "orcid": "0000-0003-1548-1524", "clpid": "Ramsey-Brian-D" }, { "family_name": "Rankin", "given_name": "John", "orcid": "0000-0002-9774-0560", "clpid": "Rankin-John" }, { "family_name": "Spandre", "given_name": "Gloria", "orcid": "0000-0003-0802-3453", "clpid": "Spandre-Gloria" }, { "family_name": "Swartz", "given_name": "Douglas A.", "orcid": "0000-0002-2954-4461", "clpid": "Swartz-Douglas-A" }, { "family_name": "Tamagawa", "given_name": "Toru", "orcid": "0000-0002-8801-6263", "clpid": "Tamagawa-Toru" }, { "family_name": "Taverna", "given_name": "Roberto", "orcid": "0000-0002-1768-618X", "clpid": "Taverna-Roberto" }, { "family_name": "Tawara", "given_name": "Yuzuru", "clpid": "Tawara-Yuzuru" }, { "family_name": "Tennant", "given_name": "Allyn F.", "orcid": "0000-0002-9443-6774", "clpid": "Tennant-Allyn-F" }, { "family_name": "Thomas", "given_name": "Nicholas E.", "orcid": "0000-0003-0411-4606", "clpid": "Thomas-Nicholas-E" }, { "family_name": "Tombesi", "given_name": "Francesco", "orcid": "0000-0002-6562-8654", "clpid": "Tombesi-Francesco" }, { "family_name": "Trois", "given_name": "Alessio", "orcid": "0000-0002-3180-6002", "clpid": "Trois-Alessio" }, { "family_name": "Tsygankov", "given_name": "Sergey S.", "orcid": "0000-0002-9679-0793", "clpid": "Tsygankov-Sergey-S" }, { "family_name": "Turolla", "given_name": "Roberto", "orcid": "0000-0003-3977-8760", "clpid": "Turolla-Roberto" }, { "family_name": "Vink", "given_name": "Jacco", "orcid": "0000-0002-4708-4219", "clpid": "Vink-Jacco" }, { "family_name": "Wu", "given_name": "Kinwah", "orcid": "0000-0002-7568-8765", "clpid": "Wu-Kinwah" }, { "family_name": "Xie", "given_name": "Fei", "orcid": "0000-0002-0105-5826", "clpid": "Xie-Fei" } ], "abstract": "We present the IXPE observation of GRB 221009A, which includes upper limits on the linear polarization degree of both prompt and afterglow emission in the soft X-ray energy band. GRB 221009A is an exceptionally bright gamma-ray burst (GRB) that reached Earth on 2022 October 9 after traveling through the dust of the Milky Way. The Imaging X-ray Polarimetry Explorer (IXPE) pointed at GRB 221009A on October 11 to observe, for the first time, the 2\u20138 keV X-ray polarization of a GRB afterglow. We set an upper limit to the polarization degree of the afterglow emission of 13.8% at a 99% confidence level. This result provides constraints on the jet opening angle and the viewing angle of the GRB, or alternatively, other properties of the emission region. Additionally, IXPE captured halo-rings of dust-scattered photons that are echoes of the GRB prompt emission. The 99% confidence level upper limit to the prompt polarization degree depends on the background model assumption, and it ranges between \u223c55% and \u223c82%. This single IXPE pointing provides both the first assessment of X-ray polarization of a GRB afterglow and the first GRB study with polarization observations of both the prompt and afterglow phases.", "doi": "10.3847/2041-8213/acba17", "issn": "2041-8205", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal Letters", "publication_date": "2023-03-01", "series_number": "1", "volume": "946", "issue": "1", "pages": "LArt. No. 21" }, { "id": "authors:we86t-a1622", "collection": "authors", "collection_id": "we86t-a1622", "cite_using_url": "https://authors.library.caltech.edu/records/we86t-a1622", "type": "article", "title": "Accretion geometry of the neutron star low mass X-ray binary Cyg X-2 from X-ray polarization measurements", "author": [ { "family_name": "Farinelli", "given_name": "R", "orcid": "0000-0003-2212-367X" }, { "family_name": "Fabiani", "given_name": "S", "orcid": "0000-0003-1533-0283" }, { "family_name": "Poutanen", "given_name": "J", "orcid": "0000-0002-0983-0049" }, { "family_name": "Ursini", "given_name": "F", "orcid": "0000-0001-9442-7897" }, { "family_name": "Ferrigno", "given_name": "C" }, { "family_name": "Bianchi", "given_name": "S", "orcid": "0000-0002-4622-4240" }, { "family_name": "Cocchi", "given_name": "M", "orcid": "0000-0002-5817-3129" }, { "family_name": "Capitanio", "given_name": "F", "orcid": "0000-0002-6384-3027" }, { "family_name": "De\u00a0Rosa", "given_name": "A", "orcid": "0000-0001-5668-6863" }, { "family_name": "Gnarini", "given_name": "A", "orcid": "0000-0002-0642-1135" }, { "family_name": "Kislat", "given_name": "F" }, { "family_name": "Matt", "given_name": "G", "orcid": "0000-0002-2152-0916" }, { "family_name": "Mikusincova", "given_name": "R", "orcid": "0000-0001-7374-843X" }, { "family_name": "Muleri", "given_name": "F", "orcid": "0000-0003-3331-3794" }, { "family_name": "Agudo", "given_name": "I", "orcid": "0000-0002-3777-6182" }, { "family_name": "Antonelli", "given_name": "L A", "orcid": "0000-0002-5037-9034" }, { "family_name": "Bachetti", "given_name": "M", "orcid": "0000-0002-4576-9337" }, { "family_name": "Baldini", "given_name": "L", "orcid": "0000-0002-9785-7726" }, { "family_name": "Baumgartner", "given_name": "W H" }, { "family_name": "Bellazzini", "given_name": "R" }, { "family_name": "Bongiorno", "given_name": "S D" }, { "family_name": "Bonino", "given_name": "R", "orcid": "0000-0002-4264-1215" }, { "family_name": "Brez", "given_name": "A" }, { "family_name": "Bucciantini", "given_name": "N", "orcid": "0000-0002-8848-1392" }, { "family_name": "Castellano", "given_name": "S" }, { "family_name": "Cavazzuti", "given_name": "E", "orcid": "0000-0001-7150-9638" }, { "family_name": "Ciprini", "given_name": "S", "orcid": "0000-0002-0712-2479" }, { "family_name": "Costa", "given_name": "E" }, { "family_name": "Del\u00a0Monte", "given_name": "E", "orcid": "0000-0002-3013-6334" }, { "family_name": "Di\u00a0Gesu", "given_name": "L" }, { "family_name": "Di\u00a0Lalla", "given_name": "N", "orcid": "0000-0002-7574-1298" }, { "family_name": "Di\u00a0Marco", "given_name": "A", "orcid": "0000-0003-0331-3259" }, { "family_name": "Donnarumma", "given_name": "I", "orcid": "0000-0002-4700-4549" }, { "family_name": "Doroshenko", "given_name": "V", "orcid": "0000-0001-8162-1105" }, { "family_name": "Dov\u010diak", "given_name": "M", "orcid": "0000-0003-0079-1239" }, { "family_name": "Ehlert", "given_name": "S R" }, { "family_name": "Enoto", "given_name": "T" }, { "family_name": "Evangelista", "given_name": "Y", "orcid": "0000-0001-6096-6710" }, { "family_name": "Ferrazzoli", "given_name": "R", "orcid": "0000-0003-1074-8605" }, { "family_name": "Garcia", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Gunji", "given_name": "S" }, { "family_name": "Hayashida", "given_name": "K" }, { "family_name": "Heyl", "given_name": "J" }, { "family_name": "Iwakiri", "given_name": "W", "orcid": "0000-0002-0207-9010" }, { "family_name": "Jorstad", "given_name": "S G", "orcid": "0000-0001-6158-1708" }, { "family_name": "Karas", "given_name": "V", "orcid": "0000-0002-5760-0459" }, { "family_name": "Kitaguchi", "given_name": "T" }, { "family_name": "Kolodziejczak", "given_name": "J J" }, { "family_name": "Krawczynski", "given_name": "H", "orcid": "0000-0002-1084-6507" }, { "family_name": "La\u00a0Monaca", "given_name": "F", "orcid": "0000-0001-8916-4156" }, { "family_name": "Latronico", "given_name": "L", "orcid": "0000-0002-0984-1856" }, { "family_name": "Liodakis", "given_name": "I", "orcid": "0000-0001-9200-4006" }, { "family_name": "Maldera", "given_name": "S" }, { "family_name": "Manfreda", "given_name": "A" }, { "family_name": "Marin", "given_name": "F", "orcid": "0000-0003-2049-2690" }, { "family_name": "Marscher", "given_name": "A P", "orcid": "0000-0001-7396-3332" }, { "family_name": "Marshall", "given_name": "H L" }, { "family_name": "Mitsuishi", "given_name": "I", "orcid": "0000-0002-9901-233X" }, { "family_name": "Mizuno", "given_name": "T", "orcid": "0000-0001-7263-0296" }, { "family_name": "Ng", "given_name": "C-Y" }, { "family_name": "O'Dell", "given_name": "S L" }, { "family_name": "Omodei", "given_name": "N", "orcid": "0000-0002-5448-7577" }, { "family_name": "Oppedisano", "given_name": "C" }, { "family_name": "Papitto", "given_name": "A", "orcid": "0000-0001-6289-7413" }, { "family_name": "Pavlov", "given_name": "G G" }, { "family_name": "Peirson", "given_name": "A L", "orcid": "0000-0001-6292-1911" }, { "family_name": "Perri", "given_name": "M", "orcid": "0000-0003-3613-4409" }, { "family_name": "Pesce-Rollins", "given_name": "M", "orcid": "0000-0003-1790-8018" }, { "family_name": "Petrucci", "given_name": "P O" }, { "family_name": "Pilia", "given_name": "M", "orcid": "0000-0001-7397-8091" }, { "family_name": "Possenti", "given_name": "A" }, { "family_name": "Puccetti", "given_name": "S", "orcid": "0000-0002-2734-7835" }, { "family_name": "Ramsey", "given_name": "B D" }, { "family_name": "Rankin", "given_name": "J" }, { "family_name": "Ratheesh", "given_name": "A", "orcid": "0000-0003-0411-4243" }, { "family_name": "Romani", "given_name": "R W" }, { "family_name": "Sgr\u00f2", "given_name": "C" }, { "family_name": "Slane", "given_name": "P" }, { "family_name": "Soffitta", "given_name": "P", "orcid": "0000-0002-7781-4104" }, { "family_name": "Spandre", "given_name": "G" }, { "family_name": "Tamagawa", "given_name": "T" }, { "family_name": "Tavecchio", "given_name": "F" }, { "family_name": "Taverna", "given_name": "R" }, { "family_name": "Tawara", "given_name": "Y" }, { "family_name": "Tennant", "given_name": "A F" }, { "family_name": "Thomas", "given_name": "N E" }, { "family_name": "Tombesi", "given_name": "F", "orcid": "0000-0002-6562-8654" }, { "family_name": "Trois", "given_name": "A", "orcid": "0000-0002-3180-6002" }, { "family_name": "Tsygankov", "given_name": "S S", "orcid": "0000-0002-9679-0793" }, { "family_name": "Turolla", "given_name": "R", "orcid": "0000-0003-3977-8760" }, { "family_name": "Vink", "given_name": "J" }, { "family_name": "Weisskopf", "given_name": "M C" }, { "family_name": "Wu", "given_name": "K" }, { "family_name": "Xie", "given_name": "F", "orcid": "0000-0002-0105-5826" }, { "family_name": "Zane", "given_name": "S", "orcid": "0000-0001-5326-880X" } ], "abstract": "

We report spectro-polarimetric results of an observational campaign of the bright neutron star low-mass X-ray binary Cyg X-2 simultaneously observed by IXPE, NICER, and INTEGRAL. Consistently with previous results, the broad-band spectrum is characterized by a lower-energy component, attributed to the accretion disc with kT_(in) ≈ 1 keV, plus unsaturated Comptonization in thermal plasma with temperature kT_e = 3 keV and optical depth τ ≈ 4, assuming a slab geometry. We measure the polarization degree in the 2–8 keV band P = 1.8 ± 0.3 per cent and polarization angle \u03d5 = 140° ± 4°, consistent with the previous X-ray polarimetric measurements by OSO-8 as well as with the direction of the radio jet which was earlier observed from the source. While polarization of the disc spectral component is poorly constrained with the IXPE data, the Comptonized emission has a polarization degree P = 4.0 ± 0.7 per cent and a polarization angle aligned with the radio jet. Our results strongly favour a spreading layer at the neutron star surface as the main source of the polarization signal. However, we cannot exclude a significant contribution from reflection off the accretion disc, as indicated by the presence of the iron fluorescence line.

", "doi": "10.1093/mnras/stac3726", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2023-03", "series_number": "3", "volume": "519", "issue": "3", "pages": "3681-3690" }, { "id": "authors:kwakt-mtg81", "collection": "authors", "collection_id": "kwakt-mtg81", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230411-764712100.2", "type": "article", "title": "A Strong X-Ray Polarization Signal from the Magnetar 1RXS J170849.0-400910", "author": [ { "family_name": "Zane", "given_name": "Silvia", "orcid": "0000-0001-5326-880X", "clpid": "Zane-Silvia" }, { "family_name": "Taverna", "given_name": "Roberto", "orcid": "0000-0002-1768-618X" }, { "family_name": "Gonz\u00e1lez\u2013Caniulef", "given_name": "Denis", "orcid": "0000-0001-5848-0180" }, { "family_name": "Muleri", "given_name": "Fabio", "orcid": "0000-0003-3331-3794" }, { "family_name": "Turolla", "given_name": "Roberto", "orcid": "0000-0003-3977-8760" }, { "family_name": "Heyl", "given_name": "Jeremy", "orcid": "0000-0001-9739-367X" }, { "family_name": "Uchiyama", "given_name": "Keisuke", "orcid": "0000-0002-7752-9389" }, { "family_name": "Ng", "given_name": "Mason", "orcid": "0000-0002-0940-6563" }, { "family_name": "Tamagawa", "given_name": "Toru", "orcid": "0000-0002-8801-6263" }, { "family_name": "Caiazzo", "given_name": "Ilaria", "orcid": "0000-0002-4770-5388", "clpid": "Caiazzo-Ilaria" }, { "family_name": "Di Lalla", "given_name": "Niccol\u00f2", "orcid": "0000-0002-7574-1298" }, { "family_name": "Marshall", "given_name": "Herman L.", "orcid": "0000-0002-6492-1293" }, { "family_name": "Bachetti", "given_name": "Matteo", "orcid": "0000-0002-4576-9337" }, { "family_name": "La Monaca", "given_name": "Fabio", "orcid": "0000-0001-8916-4156" }, { "family_name": "Gau", "given_name": "Ephraim", "orcid": "0000-0002-5250-2710" }, { "family_name": "Di Marco", "given_name": "Alessandro", "orcid": "0000-0003-0331-3259" }, { "family_name": "Baldini", "given_name": "Luca", "orcid": "0000-0002-9785-7726" }, { "family_name": "Negro", "given_name": "Michela", "orcid": "0000-0002-6548-5622" }, { "family_name": "Omodei", "given_name": "Nicola", "orcid": "0000-0002-5448-7577" }, { "family_name": "Rankin", "given_name": "John", "orcid": "0000-0002-9774-0560" }, { "family_name": "Matt", "given_name": "Giorgio", "orcid": "0000-0002-2152-0916" }, { "family_name": "Pavlov", "given_name": "George G.", "orcid": "0000-0002-7481-5259" }, { "family_name": "Kitaguchi", "given_name": "Takao" }, { "family_name": "Krawczynski", "given_name": "Henric", "orcid": "0000-0002-1084-6507" }, { "family_name": "Kislat", "given_name": "Fabian", "orcid": "0000-0001-7477-0380" }, { "family_name": "Kelly", "given_name": "Ruth", "orcid": "0000-0002-5004-3573" }, { "family_name": "Agudo", "given_name": "Iv\u00e1n", "orcid": "0000-0002-3777-6182" }, { "family_name": "Antonelli", "given_name": "Lucio A.", "orcid": "0000-0002-5037-9034" }, { "family_name": "Baumgartner", "given_name": "Wayne H.", "orcid": "0000-0002-5106-0463" }, { "family_name": "Bellazzini", "given_name": "Ronaldo", "orcid": "0000-0002-2469-7063" }, { "family_name": "Bianchi", "given_name": "Stefano", "orcid": "0000-0002-4622-4240" }, { "family_name": "Bongiorno", "given_name": "Stephen D.", "orcid": "0000-0002-0901-2097" }, { "family_name": "Bonino", "given_name": "Raffaella", "orcid": "0000-0002-4264-1215" }, { "family_name": "Brez", "given_name": "Alessandro", "orcid": "0000-0002-9460-1821" }, { "family_name": "Bucciantini", "given_name": "Niccol\u00f2", "orcid": "0000-0002-8848-1392" }, { "family_name": "Capitanio", "given_name": "Fiamma", "orcid": "0000-0002-6384-3027" }, { "family_name": "Castellano", "given_name": "Simone", "orcid": "0000-0003-1111-4292" }, { "family_name": "Cavazzuti", "given_name": "Elisabetta", "orcid": "0000-0001-7150-9638" }, { "family_name": "Chen", "given_name": "Chieng-Ting", "orcid": "0000-0002-4945-5079" }, { "family_name": "Ciprini", "given_name": "Stefano", "orcid": "0000-0002-0712-2479" }, { "family_name": "Costa", "given_name": "Enrico", "orcid": "0000-0003-4925-8523" }, { "family_name": "De Rosa", "given_name": "Alessandra", "orcid": "0000-0001-5668-6863" }, { "family_name": "Del Monte", "given_name": "Ettore", "orcid": "0000-0002-3013-6334" }, { "family_name": "Di Gesu", "given_name": "Laura", "orcid": "0000-0002-5614-5028" }, { "family_name": "Donnarumma", "given_name": "Immacolata", "orcid": "0000-0002-4700-4549" }, { "family_name": "Doroshenko", "given_name": "Victor", "orcid": "0000-0001-8162-1105" }, { "family_name": "Dov\u010diak", "given_name": "Michal", "orcid": "0000-0003-0079-1239" }, { "family_name": "Ehlert", "given_name": "Steven R.", "orcid": "0000-0003-4420-2838" }, { "family_name": "Enoto", "given_name": "Teruaki", "orcid": "0000-0003-1244-3100" }, { "family_name": "Evangelista", "given_name": "Yuri", "orcid": "0000-0001-6096-6710" }, { "family_name": "Fabiani", "given_name": "Sergio", "orcid": "0000-0003-1533-0283" }, { "family_name": "Ferrazzoli", "given_name": "Riccardo", "orcid": "0000-0003-1074-8605" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Gunji", "given_name": "Shuichi", "orcid": "0000-0002-5881-2445" }, { "family_name": "Hayashida", "given_name": "Kiyoshi", "orcid": "0000-0002-0110-6136" }, { "family_name": "Iwakiri", "given_name": "Wataru", "orcid": "0000-0002-0207-9010" }, { "family_name": "Jorstad", "given_name": "Svetlana G.", "orcid": "0000-0001-6158-1708" }, { "family_name": "Kaaret", "given_name": "Philip", "orcid": "0000-0002-3638-0637" }, { "family_name": "Karas", "given_name": "Vladimir", "orcid": "0000-0002-5760-0459" }, { "family_name": "Latronico", "given_name": "Luca", "orcid": "0000-0002-0984-1856" }, { "family_name": "Liodakis", "given_name": "Ioannis", "orcid": "0000-0001-9200-4006" }, { "family_name": "Maldera", "given_name": "Simone", "orcid": "0000-0002-0698-4421" }, { "family_name": "Manfreda", "given_name": "Alberto", "orcid": "0000-0002-0998-4953" }, { "family_name": "Marin", "given_name": "Fr\u00e9d\u00e9ric", "orcid": "0000-0003-4952-0835" }, { "family_name": "Marinucci", "given_name": "Andrea", "orcid": "0000-0002-2055-4946" }, { "family_name": "Marscher", "given_name": "Alan P.", "orcid": "0000-0001-7396-3332" }, { "family_name": "Massaro", "given_name": "Francesco", "orcid": "0000-0002-1704-9850" }, { "family_name": "Mitsuishi", "given_name": "Ikuyuki" }, { "family_name": "Mizuno", "given_name": "Tsunefumi", "orcid": "0000-0001-7263-0296" }, { "family_name": "Ng", "given_name": "C.-Y.", "orcid": "0000-0002-5847-2612" }, { "family_name": "O'Dell", "given_name": "Stephen L.", "orcid": "0000-0002-1868-8056" }, { "family_name": "Oppedisano", "given_name": "Chiara", "orcid": "0000-0001-6194-4601" }, { "family_name": "Papitto", "given_name": "Alessandro", "orcid": "0000-0001-6289-7413" }, { "family_name": "Peirson", "given_name": "Abel L.", "orcid": "0000-0001-6292-1911" }, { "family_name": "Perri", "given_name": "Matteo", "orcid": "0000-0003-3613-4409" }, { "family_name": "Pesce-Rollins", "given_name": "Melissa", "orcid": "0000-0003-1790-8018" }, { "family_name": "Petrucci", "given_name": "Pierre-Olivier", "orcid": "0000-0001-6061-3480" }, { "family_name": "Pilia", "given_name": "Maura", "orcid": "0000-0001-7397-8091" }, { "family_name": "Possenti", "given_name": "Andrea", "orcid": "0000-0001-5902-3731" }, { "family_name": "Poutanen", "given_name": "Juri", "orcid": "0000-0002-0983-0049" }, { "family_name": "Puccetti", "given_name": "Simonetta", "orcid": "0000-0002-2734-7835" }, { "family_name": "Ramsey", "given_name": "Brian D.", "orcid": "0000-0003-1548-1524" }, { "family_name": "Ratheesh", "given_name": "Ajay", "orcid": "0000-0003-0411-4243" }, { "family_name": "Roberts", "given_name": "Oliver J.", "orcid": "0000-0002-7150-9061" }, { "family_name": "Romani", "given_name": "Roger W.", "orcid": "0000-0001-6711-3286" }, { "family_name": "Sgr\u00f3", "given_name": "Carmelo", "orcid": "0000-0001-5676-6214" }, { "family_name": "Slane", "given_name": "Patrick", "orcid": "0000-0002-6986-6756" }, { "family_name": "Soffitta", "given_name": "Paolo", "orcid": "0000-0002-7781-4104" }, { "family_name": "Spandre", "given_name": "Gloria", "orcid": "0000-0003-0802-3453" }, { "family_name": "Swartz", "given_name": "Douglas A.", "orcid": "0000-0002-2954-4461" }, { "family_name": "Tavecchio", "given_name": "Fabrizio", "orcid": "0000-0003-0256-0995" }, { "family_name": "Tawara", "given_name": "Yuzuru" }, { "family_name": "Tennant", "given_name": "Allyn F.", "orcid": "0000-0002-9443-6774" }, { "family_name": "Thomas", "given_name": "Nicholas E.", "orcid": "0000-0003-0411-4606" }, { "family_name": "Tombesi", "given_name": "Francesco", "orcid": "0000-0002-6562-8654" }, { "family_name": "Trois", "given_name": "Alessio", "orcid": "0000-0002-3180-6002" }, { "family_name": "Tsygankov", "given_name": "Sergey S.", "orcid": "0000-0002-9679-0793" }, { "family_name": "Vink", "given_name": "Jacco", "orcid": "0000-0002-4708-4219" }, { "family_name": "Weisskopf", "given_name": "Martin C.", "orcid": "0000-0002-5270-4240" }, { "family_name": "Wu", "given_name": "Kinwah", "orcid": "0000-0002-7568-8765" }, { "family_name": "Xie", "given_name": "Fei", "orcid": "0000-0002-0105-5826" } ], "abstract": "Magnetars are the most strongly magnetized neutron stars, and one of the most promising targets for X-ray polarimetric measurements. We present here the first Imaging X-ray Polarimetry Explorer observation of the magnetar 1RXS J170849.0-400910, jointly analyzed with a new Swift observation and archival NICER data. The total (energy- and phase-integrated) emission in the 2\u20138 keV energy range is linerarly polarized, at a \u223c35% level. The phase-averaged polarization signal shows a marked increase with energy, ranging from \u223c20% at 2\u20133 keV up to \u223c80% at 6\u20138 keV, while the polarization angle remains constant. This indicates that radiation is mostly polarized in a single direction. The spectrum is well reproduced by a combination of either two thermal (blackbody) components or a blackbody and a power law. Both the polarization degree and angle also show a variation with the spin phase, and the former is almost anticorrelated with the source counts in the 2\u20138 and 2\u20134 keV bands. We discuss the possible implications and interpretations, based on a joint analysis of the spectral, polarization, and pulsation properties of the source. A scenario in which the surface temperature is not homogeneous, with a hotter cap covered by a gaseous atmosphere and a warmer region in a condensed state, provides a satisfactory description of both the phase- and energy-dependent spectro-polarimetric data. The (comparatively) small size of the two emitting regions, required to explain the observed pulsations, does not allow to reach a robust conclusion about the presence of vacuum birefringence effects.", "doi": "10.3847/2041-8213/acb703", "issn": "2041-8205", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal Letters", "publication_date": "2023-02-20", "series_number": "2", "volume": "944", "issue": "2", "pages": "Art. No. L27" }, { "id": "authors:xkkgk-vzw61", "collection": "authors", "collection_id": "xkkgk-vzw61", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230314-845495900.53", "type": "article", "title": "Revisiting the Galactic X-Ray Binary MAXI J1631\u2013479: Implications for High Inclination and a Massive Black Hole", "author": [ { "family_name": "Rout", "given_name": "Sandeep K.", "orcid": "0000-0001-7590-5099", "clpid": "Rout-Sandeep-K" }, { "family_name": "Vadawale", "given_name": "Santosh", "orcid": "0000-0002-2050-0913", "clpid": "Vadawale-Santosh" }, { "family_name": "Garc\u00eda", "given_name": "Javier", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Connors", "given_name": "Riley", "orcid": "0000-0002-8908-759X", "clpid": "Connors-Riley-M-T" } ], "abstract": "X-ray spectroscopy of Galactic black hole binaries serves as a powerful tool to gain an overall understanding of the system. Not only can the properties of the accretion disk be studied in detail, the fundamental properties of the black hole such as spin and mass can also be measured. In this work we carry out a comprehensive spectral analysis of the\u00a0X-ray binary MAXI J1631\u2013479 using data from NICER and NuSTAR observatories. We trace the evolution of the accretion disk properties, such as density, ionization, and Fe abundance, as the source transitions from a disk-dominated soft state to a power-law-dominated hard intermediate state. As expected the disc ionization increased with hardness while the density and abundance (at solar values) remained unchanged. We provide strong constraints on the spin of the black hole (a > 0.996) and the inclination of the inner disk (50\u00b0\u201370\u00b0). We also use the soft-state NICER observations to constrain the black hole mass using distance estimates from optical observations. We find the probable mass of the black hole to be much higher than its X-ray binary counterparts with a conservative lower limit of 15 M_\u2299 at 4.5 kpc.", "doi": "10.3847/1538-4357/acaaa4", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2023-02-10", "series_number": "1", "volume": "944", "issue": "1", "pages": "Art. No. 68" }, { "id": "authors:tjs7d-sf521", "collection": "authors", "collection_id": "tjs7d-sf521", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230221-19480300.56", "type": "article", "title": "Polarization Properties of the Weakly Magnetized Neutron Star X-Ray Binary GS 1826-238 in the High Soft State", "author": [ { "family_name": "Capitanio", "given_name": "Fiamma", "orcid": "0000-0002-6384-3027", "clpid": "Capitanio-Fiamma" }, { "family_name": "Fabiani", "given_name": "Sergio", "orcid": "0000-0003-1533-0283" }, { "family_name": "Gnarini", "given_name": "Andrea", "orcid": "0000-0002-0642-1135" }, { "family_name": "Ursini", "given_name": "Francesco", "orcid": "0000-0001-9442-7897" }, { "family_name": "Ferrigno", "given_name": "Carlo", "orcid": "0000-0003-1429-1059" }, { "family_name": "Matt", "given_name": "Giorgio", "orcid": "0000-0002-2152-0916" }, { "family_name": "Poutanen", "given_name": "Juri", "orcid": "0000-0002-0983-0049" }, { "family_name": "Cocchi", "given_name": "Massimo", "orcid": "0000-0002-5817-3129" }, { "family_name": "Mikusincova", "given_name": "Romana", "orcid": "0000-0001-7374-843X" }, { "family_name": "Farinelli", "given_name": "Ruben", "orcid": "0000-0003-2212-367X" }, { "family_name": "Bianchi", "given_name": "Stefano", "orcid": "0000-0002-4622-4240" }, { "family_name": "Kajava", "given_name": "Jari J. E.", "orcid": "0000-0002-3010-8333" }, { "family_name": "Muleri", "given_name": "Fabio", "orcid": "0000-0003-3331-3794" }, { "family_name": "Sanchez-Fernandez", "given_name": "Celia", "orcid": "0000-0002-0778-6048" }, { "family_name": "Soffitta", "given_name": "Paolo", "orcid": "0000-0002-7781-4104" }, { "family_name": "Wu", "given_name": "Kinwah", "orcid": "0000-0002-7568-8765" }, { "family_name": "Agudo", "given_name": "Iv\u00e1n", "orcid": "0000-0002-3777-6182" }, { "family_name": "Antonelli", "given_name": "Lucio A.", "orcid": "0000-0002-5037-9034" }, { "family_name": "Bachetti", "given_name": "Matteo", "orcid": "0000-0002-4576-9337" }, { "family_name": "Baldini", "given_name": "Luca", "orcid": "0000-0002-9785-7726" }, { "family_name": "Baumgartner", "given_name": "Wayne H.", "orcid": "0000-0002-5106-0463" }, { "family_name": "Bellazzini", "given_name": "Ronaldo", "orcid": "0000-0002-2469-7063" }, { "family_name": "Bongiorno", "given_name": "Stephen D.", "orcid": "0000-0002-0901-2097" }, { "family_name": "Bonino", "given_name": "Raffaella", "orcid": "0000-0002-4264-1215" }, { "family_name": "Brez", "given_name": "Alessandro", "orcid": "0000-0002-9460-1821" }, { "family_name": "Bucciantini", "given_name": "Niccol\u00f2", "orcid": "0000-0002-8848-1392" }, { "family_name": "Castellano", "given_name": "Simone", "orcid": "0000-0003-1111-4292" }, { "family_name": "Cavazzuti", "given_name": "Elisabetta", "orcid": "0000-0001-7150-9638" }, { "family_name": "Ciprini", "given_name": "Stefano", "orcid": "0000-0002-0712-2479" }, { "family_name": "Costa", "given_name": "Enrico", "orcid": "0000-0003-4925-8523" }, { "family_name": "De Rosa", "given_name": "Alessandra", "orcid": "0000-0001-5668-6863" }, { "family_name": "Del Monte", "given_name": "Ettore", "orcid": "0000-0002-3013-6334" }, { "family_name": "Di Gesu", "given_name": "Laura", "orcid": "0000-0002-5614-5028" }, { "family_name": "Di Lalla", "given_name": "Niccol\u00f2", "orcid": "0000-0002-7574-1298" }, { "family_name": "Di Marco", "given_name": "Alessandro", "orcid": "0000-0003-0331-3259" }, { "family_name": "Donnarumma", "given_name": "Immacolata", "orcid": "0000-0002-4700-4549" }, { "family_name": "Doroshenko", "given_name": "Victor", "orcid": "0000-0001-8162-1105" }, { "family_name": "Dov\u010diak", "given_name": "Michal", "orcid": "0000-0003-0079-1239" }, { "family_name": "Ehlert", "given_name": "Steven R.", "orcid": "0000-0003-4420-2838" }, { "family_name": "Enoto", "given_name": "Teruaki", "orcid": "0000-0003-1244-3100" }, { "family_name": "Evangelista", "given_name": "Yuri", "orcid": "0000-0001-6096-6710" }, { "family_name": "Ferrazzoli", "given_name": "Riccardo", "orcid": "0000-0003-1074-8605" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Gunji", "given_name": "Shuichi", "orcid": "0000-0002-5881-2445" }, { "family_name": "Hayashida", "given_name": "Kiyoshi", "orcid": "0000-0002-0110-6136" }, { "family_name": "Heyl", "given_name": "Jeremy", "orcid": "0000-0001-9739-367X" }, { "family_name": "Iwakiri", "given_name": "Wataru", "orcid": "0000-0002-0207-9010" }, { "family_name": "Jorstad", "given_name": "Svetlana G.", "orcid": "0000-0001-6158-1708" }, { "family_name": "Karas", "given_name": "Vladimir", "orcid": "0000-0002-5760-0459" }, { "family_name": "Kitaguchi", "given_name": "Takao" }, { "family_name": "Krawczynski", "given_name": "Henric", "orcid": "0000-0002-1084-6507" }, { "family_name": "La Monaca", "given_name": "Fabio", "orcid": "0000-0001-8916-4156" }, { "family_name": "Latronico", "given_name": "Luca", "orcid": "0000-0002-0984-1856" }, { "family_name": "Liodakis", "given_name": "Ioannis", "orcid": "0000-0001-9200-4006" }, { "family_name": "Maldera", "given_name": "Simone", "orcid": "0000-0002-0698-4421" }, { "family_name": "Manfreda", "given_name": "Alberto", "orcid": "0000-0002-0998-4953" }, { "family_name": "Marin", "given_name": "Fr\u00e9d\u00e9ric", "orcid": "0000-0003-4952-0835" }, { "family_name": "Marinucci", "given_name": "Andrea", "orcid": "0000-0002-2055-4946" }, { "family_name": "Marscher", "given_name": "Alan P.", "orcid": "0000-0001-7396-3332" }, { "family_name": "Marshall", "given_name": "Herman L.", "orcid": "0000-0002-6492-1293" }, { "family_name": "Mitsuishi", "given_name": "Ikuyuki" }, { "family_name": "Mizuno", "given_name": "Tsunefumi", "orcid": "0000-0001-7263-0296" }, { "family_name": "Ng", "given_name": "C.-Y.", "orcid": "0000-0002-5847-2612" }, { "family_name": "O'Dell", "given_name": "Stephen L.", "orcid": "0000-0002-1868-8056" }, { "family_name": "Omodei", "given_name": "Nicola", "orcid": "0000-0002-5448-7577" }, { "family_name": "Oppedisano", "given_name": "Chiara", "orcid": "0000-0001-6194-4601" }, { "family_name": "Papitto", "given_name": "Alessandro", "orcid": "0000-0001-6289-7413" }, { "family_name": "Pavlov", "given_name": "George G.", "orcid": "0000-0002-7481-5259" }, { "family_name": "Peirson", "given_name": "Abel L.", "orcid": "0000-0001-6292-1911" }, { "family_name": "Perri", "given_name": "Matteo", "orcid": "0000-0003-3613-4409" }, { "family_name": "Pesce-Rollins", "given_name": "Melissa", "orcid": "0000-0003-1790-8018" }, { "family_name": "Petrucci", "given_name": "Pierre-Olivier", "orcid": "0000-0001-6061-3480" }, { "family_name": "Pilia", "given_name": "Maura", "orcid": "0000-0001-7397-8091" }, { "family_name": "Possenti", "given_name": "Andrea", "orcid": "0000-0001-5902-3731" }, { "family_name": "Puccetti", "given_name": "Simonetta", "orcid": "0000-0002-2734-7835" }, { "family_name": "Ramsey", "given_name": "Brian D.", "orcid": "0000-0003-1548-1524" }, { "family_name": "Rankin", "given_name": "John", "orcid": "0000-0002-9774-0560" }, { "family_name": "Ratheesh", "given_name": "Ajay", "orcid": "0000-0003-0411-4243" }, { "family_name": "Romani", "given_name": "Roger W.", "orcid": "0000-0001-6711-3286" }, { "family_name": "Sgr\u00f2", "given_name": "Carmelo", "orcid": "0000-0001-5676-6214" }, { "family_name": "Slane", "given_name": "Patrick", "orcid": "0000-0002-6986-6756" }, { "family_name": "Spandre", "given_name": "Gloria", "orcid": "0000-0003-0802-3453" }, { "family_name": "Tamagawa", "given_name": "Toru", "orcid": "0000-0002-8801-6263" }, { "family_name": "Tavecchio", "given_name": "Fabrizio", "orcid": "0000-0003-0256-0995" }, { "family_name": "Taverna", "given_name": "Roberto", "orcid": "0000-0002-1768-618X" }, { "family_name": "Tawara", "given_name": "Yuzuru" }, { "family_name": "Tennant", "given_name": "Allyn F.", "orcid": "0000-0002-9443-6774" }, { "family_name": "Thomas", "given_name": "Nicholas E.", "orcid": "0000-0003-0411-4606" }, { "family_name": "Tombesi", "given_name": "Francesco", "orcid": "0000-0002-6562-8654" }, { "family_name": "Trois", "given_name": "Alessio", "orcid": "0000-0002-3180-6002" }, { "family_name": "Tsygankov", "given_name": "Sergey S.", "orcid": "0000-0002-9679-0793" }, { "family_name": "Turolla", "given_name": "Roberto", "orcid": "0000-0003-3977-8760" }, { "family_name": "Vink", "given_name": "Jacco", "orcid": "0000-0002-4708-4219" }, { "family_name": "Weisskopf", "given_name": "Martin C.", "orcid": "0000-0002-5270-4240" }, { "family_name": "Xie", "given_name": "Fei", "orcid": "0000-0002-0105-5826" }, { "family_name": "Zane", "given_name": "Silvia", "orcid": "0000-0001-5326-880X" } ], "abstract": "The launch of the Imaging X-ray Polarimetry Explorer (IXPE) on 2021 December 9 has opened a new window in X-ray astronomy. We report here the results of the first IXPE observation of a weakly magnetized neutron star, GS 1826\u2212238, performed on 2022 March 29\u201331 when the source was in a high soft state. An upper limit (99.73% confidence level) of 1.3% for the linear polarization degree is obtained over the IXPE 2\u20138 keV energy range. Coordinated INTEGRAL and NICER observations were carried out simultaneously with IXPE. The spectral parameters obtained from the fits to the broadband spectrum were used as inputs for Monte Carlo simulations considering different possible geometries of the X-ray emitting region. Comparing the IXPE upper limit with these simulations, we can put constraints on the geometry and inclination angle of GS 1826\u2013238.", "doi": "10.3847/1538-4357/acae88", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2023-02-01", "series_number": "2", "volume": "943", "issue": "2", "pages": "Art. No. 129" }, { "id": "authors:sm7k9-1qe15", "collection": "authors", "collection_id": "sm7k9-1qe15", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230314-846094500.79", "type": "article", "title": "X-Ray Polarization Observations of BL Lacertae", "author": [ { "family_name": "Middei", "given_name": "Riccardo", "orcid": "0000-0001-9815-9092", "clpid": "Middei-Riccardo" }, { "family_name": "Liodakis", "given_name": "Ioannis", "orcid": "0000-0001-9200-4006", "clpid": "Liodakis-Ioannis" }, { "family_name": "Perri", "given_name": "Matteo", "orcid": "0000-0003-3613-4409", "clpid": "Perri-Matteo" }, { "family_name": "Puccetti", "given_name": "Simonetta", "orcid": "0000-0002-2734-7835", "clpid": "Puccetti-Simonetta" }, { "family_name": "Cavazzuti", "given_name": "Elisabetta", "orcid": "0000-0001-7150-9638", "clpid": "Cavazzuti-Elisabetta" }, { "family_name": "Di Gesu", "given_name": "Laura", "orcid": "0000-0002-5614-5028", "clpid": "Di-Gesu-Laura" }, { "family_name": "Ehlert", "given_name": "Steven R.", "orcid": "0000-0003-1111-4292", "clpid": "Ehlert-Steven-R" }, { "family_name": "Madejski", "given_name": "Grzegorz", "clpid": "Madejski-Grzegorz" }, { "family_name": "Marscher", "given_name": "Alan P.", "orcid": "0000-0001-7396-3332", "clpid": "Marscher-Alan-P" }, { "family_name": "Marshall", "given_name": "Herman L.", "orcid": "0000-0002-6492-1293", "clpid": "Marshall-Herman-L" }, { "family_name": "Muleri", "given_name": "Fabio", "orcid": "0000-0003-3331-3794", "clpid": "Muleri-Fabio" }, { "family_name": "Negro", "given_name": "Michela", "orcid": "0000-0002-6548-5622", "clpid": "Negro-Michela" }, { "family_name": "Jorstad", "given_name": "Svetlana G.", "orcid": "0000-0001-6158-1708", "clpid": "Jorstad-Svetlana-G" }, { "family_name": "Ag\u00eds-Gonz\u00e1lez", "given_name": "Beatriz", "orcid": "0000-0001-7702-8931", "clpid": "Ag\u00eds-Gonz\u00e1lez-Beatriz" }, { "family_name": "Agudo", "given_name": "Ivan", "orcid": "0000-0002-3777-6182", "clpid": 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"0000-0002-1704-9850", "clpid": "Massaro-Francesco" }, { "family_name": "Matt", "given_name": "Giorgio", "orcid": "0000-0002-2152-0916", "clpid": "Matt-Giorgio" }, { "family_name": "Mitsuishi", "given_name": "Ikuyuki", "clpid": "Mitsuishi-Ikuyuki" }, { "family_name": "Ng", "given_name": "C.-Y.", "orcid": "0000-0002-5847-2612", "clpid": "Ng-Stephen-Chi-Yung" }, { "family_name": "O'Dell", "given_name": "Stephen L.", "orcid": "0000-0002-1868-8056", "clpid": "O'Dell-Stephen-L" }, { "family_name": "Oppedisano", "given_name": "Chiara", "orcid": "0000-0001-6194-4601", "clpid": "Oppedisano-Chiara" }, { "family_name": "Papitto", "given_name": "Alessandro", "orcid": "0000-0001-6289-7413", "clpid": "Papitto-Alessandro" }, { "family_name": "Pavlov", "given_name": "George G.", "orcid": "0000-0002-7481-5259", "clpid": "Pavlov-George-G" }, { "family_name": "Peirson", "given_name": "Abel L.", "orcid": "0000-0001-6292-1911", "clpid": "Peirson-Abel-L" }, { "family_name": "Pesce-Rollins", "given_name": "Melissa", "orcid": "0000-0003-1790-8018", "clpid": "Pesce-Rollins-Melissa" }, { "family_name": "Petrucci", "given_name": "Pierre-Olivier", "orcid": "0000-0001-6061-3480", "clpid": "Petrucci-Pierre-Olivier" }, { "family_name": "Pilia", "given_name": "Maura", "orcid": "0000-0001-7397-8091", "clpid": "Pilia-Maura" }, { "family_name": "Possenti", "given_name": "Andrea", "orcid": "0000-0001-5902-3731", "clpid": "Possenti-Andrea" }, { "family_name": "Ramsey", "given_name": "Brian D.", "clpid": "Ramsey-Brian-D" }, { "family_name": "Rankin", "given_name": "John", "orcid": "0000-0002-9774-0560", "clpid": "Rankin-John" }, { "family_name": "Ratheesh", "given_name": "Ajay", "orcid": "0000-0003-0411-4243", "clpid": "Ratheesh-Ajay" }, { "family_name": "Romani", "given_name": "Roger W.", "orcid": "0000-0001-6711-3286", "clpid": "Romani-Roger-W" }, { "family_name": "Sgr\u00f3", "given_name": "Carmelo", "orcid": "0000-0001-5676-6214", "clpid": "Sgr\u00f3-Carmelo" }, { "family_name": "Slane", "given_name": "Patrick", "orcid": "0000-0002-6986-6756", "clpid": "Slane-Patrick" }, { "family_name": "Spandre", "given_name": "Gloria", "orcid": "0000-0003-0802-3453", "clpid": "Spandre-Gloria" }, { "family_name": "Tamagawa", "given_name": "Toru", "orcid": "0000-0002-8801-6263", "clpid": "Tamagawa-Toru" }, { "family_name": "Taverna", "given_name": "Roberto", "orcid": "0000-0002-1768-618X", "clpid": "Taverna-Roberto" }, { "family_name": "Tawara", "given_name": "Yuzuru", "clpid": "Tawara-Yuzuru" }, { "family_name": "Tennant", "given_name": "Allyn F.", "orcid": "0000-0002-9443-6774", "clpid": "Tennant-Allyn-F" }, { "family_name": "Thomas", "given_name": "Nicholas E.", "orcid": "0000-0003-0411-4606", "clpid": "Thomas-Nicholas-E" }, { "family_name": "Tombesi", "given_name": "Francesco", "orcid": "0000-0002-6562-8654", "clpid": "Tombesi-Francesco" }, { "family_name": "Trois", "given_name": "Alessio", "orcid": "0000-0002-3180-6002", "clpid": "Trois-Alessio" }, { "family_name": "Tsygankov", "given_name": "Sergey S.", "orcid": "0000-0002-9679-0793", "clpid": "Tsygankov-Sergey-S" }, { "family_name": "Turolla", "given_name": "Roberto", "orcid": "0000-0003-3977-8760", "clpid": "Turolla-Roberto" }, { "family_name": "Vink", "given_name": "Jacco", "orcid": "0000-0002-4708-4219", "clpid": "Vink-Jacco" }, { "family_name": "Weisskopf", "given_name": "Martin C.", "orcid": "0000-0002-5270-4240", "clpid": "Weisskopf-Martin-C" }, { "family_name": "Wu", "given_name": "Kinwah", "orcid": "0000-0002-7568-8765", "clpid": "Wu-Kinwah" }, { "family_name": "Xie", "given_name": "Fei", "orcid": "0000-0002-0105-5826", "clpid": "Xie-Fei" }, { "family_name": "Zane", "given_name": "Silvia", "orcid": "0000-0001-5326-880X", "clpid": "Zane-Silvia" } ], "abstract": "Blazars are a class of jet-dominated active galactic nuclei with a typical double-humped spectral energy distribution. It is of common consensus that the synchrotron emission is responsible for the low frequency peak, while the origin of the high frequency hump is still debated. The analysis of X-rays and their polarization can provide a valuable tool to understand the physical mechanisms responsible for the origin of high-energy emission of blazars. We report the first observations of BL Lacertae (BL Lac) performed with the Imaging X-ray Polarimetry Explorer, from which an upper limit to the polarization degree \u03a0_X < 12.6% was found in the 2\u20138 keV band. We contemporaneously measured the polarization in radio, infrared, and optical wavelengths. Our multiwavelength polarization analysis disfavors a significant contribution of proton-synchrotron radiation to the X-ray emission at these epochs. Instead, it supports a leptonic origin for the X-ray emission in BL Lac.", "doi": "10.3847/2041-8213/aca281", "issn": "2041-8205", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal Letters", "publication_date": "2023-01-01", "series_number": "1", "volume": "942", "issue": "1", "pages": "Art. No. L10" }, { "id": "authors:rnp3v-80k61", "collection": "authors", "collection_id": "rnp3v-80k61", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230314-844891400.8", "type": "article", "title": "Constraining the X-ray reflection in low accretion-rate active galactic nuclei using XMM-Newton, NuSTAR, and Swift", "author": [ { "family_name": "Diaz", "given_name": "Y.", "orcid": "0000-0002-8604-1158", "clpid": "Diaz-Yaherlyn" }, { "family_name": "Hern\u00e1ndez-Garc\u00eda", "given_name": "L.", "orcid": "0000-0002-8606-6961", "clpid": "Hern\u00e1ndez-Garc\u00eda-Lorena" }, { "family_name": "Ar\u00e9valo", "given_name": "P.", "orcid": "0000-0001-8503-9809", "clpid": "Ar\u00e9valo-Patricia" }, { "family_name": "L\u00f3pez-Navas", "given_name": "E.", "clpid": "L\u00f3pez-Navas-E" }, { "family_name": "Ricci", "given_name": "C.", "orcid": "0000-0001-5231-2645", "clpid": "Ricci-Claudio" }, { "family_name": "Koss", "given_name": "M.", "orcid": "0000-0002-7998-9581", "clpid": "Koss-Michael-J" }, { "family_name": "Gonz\u00e1lez-Mart\u00edn", "given_name": "O.", "orcid": "0000-0002-2356-8358", "clpid": "Gonz\u00e1lez-Mart\u00edn-Omaira" }, { "family_name": "Balokovi\u0107", "given_name": "M.", "orcid": "0000-0003-0476-6647", "clpid": "Balokovi\u0107-Mislav" }, { "family_name": "Osorio-Clavijo", "given_name": "N.", "orcid": "0000-0002-3467-8077", "clpid": "Osorio-Clavijo-Natalia" }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Malizia", "given_name": "A.", "orcid": "0000-0002-6558-1163", "clpid": "Malizia-Angela" } ], "abstract": "An interesting feature of active galactic nuclei (AGN) accreting at low rates is the weakness of the reflection features in their X-ray spectra, which may result from the gradual disappearance of the torus with decreasing accretion rates. It has been suggested that low-luminosity AGN (LLAGN) would exhibit a different reflector configuration than high-luminosity AGN, covering a smaller fraction of the sky or simply having less material. Additionally, we note that the determination of the spectral index (\u0393) and the cut-off energy of the primary power-law emission is affected by the inclusion of reflection models, showing their importance in studying accretion mechanisms. This is especially valid in the case of the LLAGN which has previously shown a high dispersion in the relation between \u0393 and the accretion rate. \n\nAims. Our purpose is to constrain the geometry and column density of the reflector in a sample of LLAGN covering a broad X-ray range of energy by combining data from XMM-Newton+ NuSTAR + Swift. The spectral analysis also allows us to investigate the accretion mechanism in LLAGN. \n\nMethods. We used XMM-Newton+ NuSTAR + Swift observations of a hard X-ray flux-limited sample of 17 LLAGN from BASS/DR2 with accretion rates of \u03bb_(Edd)\u2004=\u2004L_(Bol)/L_(Edd)\u2004< 10\u207b\u00b3. We fit all spectra using the reflection model for torus (BORUS) and accretion disk (XILLVER) reflectors. \n\nResults. We found a tentative correlation between the torus column density and the accretion rate, with LLAGN showing a lower column density than the high-luminosity objects. We also confirm the relation between \u0393 and \u03bb_(Edd), with a smaller scatter than previously reported, thanks to the inclusion of high-energy data and the reflection models. Our results are consistent with a break at \u03bb_(Edd)\u2004\u223c\u200410\u207b\u00b3, which is suggestive of a different accretion mechanism compared with higher accretion AGN.", "doi": "10.1051/0004-6361/202244678", "issn": "0004-6361", "publisher": "EDP Sciences", "publication": "Astronomy and Astrophysics", "publication_date": "2023-01", "volume": "669", "pages": "Art. No. A114" }, { "id": "authors:dqsvz-9ty06", "collection": "authors", "collection_id": "dqsvz-9ty06", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230314-846094500.78", "type": "article", "title": "Vela pulsar wind nebula X-rays are polarized to near the synchrotron limit", "author": [ { "family_name": "Xie", "given_name": "Fei", "orcid": "0000-0002-0105-5826", "clpid": "Xie-Fei" }, { "family_name": "Di Marco", "given_name": "Alessandro", "orcid": "0000-0003-0331-3259" }, { "family_name": "La Monaca", "given_name": "Fabio", "orcid": "0000-0001-8916-4156" }, { "family_name": "Liu", "given_name": "Kuan" }, { "family_name": "Muleri", "given_name": "Fabio", "orcid": "0000-0003-3331-3794" }, { "family_name": "Bucciantini", "given_name": "Niccol\u00f2", "orcid": "0000-0002-8848-1392" }, { "family_name": "Romani", "given_name": "Roger W.", "orcid": "0000-0001-6711-3286" }, { "family_name": "Costa", "given_name": "Enrico", "orcid": "0000-0003-4925-8523" }, { "family_name": "Rankin", "given_name": "John", "orcid": "0000-0002-9774-0560" }, { "family_name": "Soffitta", "given_name": "Paolo", "orcid": "0000-0002-7781-4104" }, { "family_name": "Bachetti", "given_name": "Matteo", "orcid": "0000-0002-4576-9337" }, { "family_name": "Di Lalla", "given_name": "Niccol\u00f2", "orcid": "0000-0002-7574-1298" }, { "family_name": "Fabiani", "given_name": "Sergio", "orcid": "0000-0003-1533-0283" }, { "family_name": "Ferrazzoli", "given_name": "Riccardo", "orcid": "0000-0003-1074-8605" }, { "family_name": "Gunji", "given_name": "Shuichi", "orcid": "0000-0002-5881-2445" }, { "family_name": "Latronico", "given_name": "Luca", "orcid": "0000-0002-0984-1856" }, { "family_name": "Negro", "given_name": "Michela", "orcid": "0000-0002-6548-5622" }, { "family_name": "Omodei", "given_name": "Nicola", "orcid": "0000-0002-5448-7577" }, { "family_name": "Pilia", "given_name": "Maura", "orcid": "0000-0001-7397-8091" }, { "family_name": "Trois", "given_name": "Alessio", "orcid": "0000-0002-3180-6002" }, { "family_name": "Watanabe", "given_name": "Eri", "orcid": "0000-0003-0622-8703" }, { "family_name": "Agudo", "given_name": "Iv\u00e1n", "orcid": "0000-0002-3777-6182" }, { "family_name": "Antonelli", "given_name": "Lucio A.", "orcid": "0000-0002-5037-9034" }, { "family_name": "Baldini", "given_name": "Luca", "orcid": "0000-0002-9785-7726" }, { "family_name": "Baumgartner", "given_name": "Wayne H.", "orcid": "0000-0002-5106-0463" }, { "family_name": "Bellazzini", "given_name": "Ronaldo", "orcid": "0000-0002-2469-7063" }, { "family_name": "Bianchi", "given_name": "Stefano", "orcid": "0000-0002-4622-4240" }, { "family_name": "Bongiorno", "given_name": "Stephen D.", "orcid": "0000-0002-0901-2097" }, { "family_name": "Bonino", "given_name": "Raffaella", "orcid": "0000-0002-4264-1215" }, { "family_name": "Brez", "given_name": "Alessandro", "orcid": "0000-0002-9460-1821" }, { "family_name": "Capitanio", "given_name": "Fiamma", "orcid": "0000-0002-6384-3027" }, { "family_name": "Castellano", "given_name": "Simone", "orcid": "0000-0003-1111-4292" }, { "family_name": "Cavazzuti", "given_name": "Elisabetta", "orcid": "0000-0001-7150-9638" }, { "family_name": "Ciprini", "given_name": "Stefano", "orcid": "0000-0002-0712-2479" }, { "family_name": "De Rosa", "given_name": "Alessandra", "orcid": "0000-0001-5668-6863" }, { "family_name": "Del Monte", "given_name": "Ettore", "orcid": "0000-0002-3013-6334" }, { "family_name": "Di Gesu", "given_name": "Laura", "orcid": "0000-0002-5614-5028" }, { "family_name": "Donnarumma", "given_name": "Immacolata", "orcid": "0000-0002-4700-4549" }, { "family_name": "Doroshenko", "given_name": "Victor", "orcid": "0000-0001-8162-1105" }, { "family_name": "Dov\u010diak", "given_name": "Michal", "orcid": "0000-0003-0079-1239" }, { "family_name": "Ehlert", "given_name": "Steven R.", "orcid": "0000-0003-4420-2838" }, { "family_name": "Enoto", "given_name": "Teruaki" }, { "family_name": "Evangelista", "given_name": "Yuri", "orcid": "0000-0001-6096-6710" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Hayashida", "given_name": "Kiyoshi", "orcid": "0000-0002-0110-6136" }, { "family_name": "Heyl", "given_name": "Jeremy", "orcid": "0000-0001-9739-367X" }, { "family_name": "Iwakiri", "given_name": "Wataru", "orcid": "0000-0002-0207-9010" }, { "family_name": "Jorstad", "given_name": "Svetlana G.", "orcid": "0000-0001-6158-1708" }, { "family_name": "Karas", "given_name": "Vladimir", "orcid": "0000-0002-5760-0459" }, { "family_name": "Kitaguchi", "given_name": "Takao" }, { "family_name": "Krawczynski", "given_name": "Henric", "orcid": "0000-0002-1084-6507" }, { "family_name": "Liodakis", "given_name": "Ioannis", "orcid": "0000-0001-9200-4006" }, { "family_name": "Maldera", "given_name": "Simone", "orcid": "0000-0002-0698-4421" }, { "family_name": "Manfreda", "given_name": "Alberto", "orcid": "0000-0002-0998-4953" }, { "family_name": "Marin", "given_name": "Fr\u00e9d\u00e9ric", "orcid": "0000-0003-4952-0835" }, { "family_name": "Marinucci", "given_name": "Andrea", "orcid": "0000-0002-2055-4946" }, { "family_name": "Marscher", "given_name": "Alan P.", "orcid": "0000-0001-7396-3332" }, { "family_name": "Marshall", "given_name": "Herman L.", "orcid": "0000-0002-6492-1293" }, { "family_name": "Massaro", "given_name": "Francesco", "orcid": "0000-0002-1704-9850" }, { "family_name": "Matt", "given_name": "Giorgio", "orcid": "0000-0002-2152-0916" }, { "family_name": "Mitsuishi", "given_name": "Ikuyuki" }, { "family_name": "Mizuno", "given_name": "Tsunefumi", "orcid": "0000-0001-7263-0296" }, { "family_name": "Ng", "given_name": "C.-Y.", "orcid": "0000-0002-5847-2612" }, { "family_name": "O'Dell", "given_name": "Stephen L.", "orcid": "0000-0002-1868-8056" }, { "family_name": "Oppedisano", "given_name": "Chiara", "orcid": "0000-0001-6194-4601" }, { "family_name": "Papitto", "given_name": "Alessandro", "orcid": "0000-0001-6289-7413" }, { "family_name": "Pavlov", "given_name": "George G.", "orcid": "0000-0002-7481-5259" }, { "family_name": "Peirson", "given_name": "Abel L.", "orcid": "0000-0001-6292-1911" }, { "family_name": "Perri", "given_name": "Matteo", "orcid": "0000-0003-3613-4409" }, { "family_name": "Pesce-Rollins", "given_name": "Melissa", "orcid": "0000-0003-1790-8018" }, { "family_name": "Petrucci", "given_name": "Pierre-Olivier", "orcid": "0000-0001-6061-3480" }, { "family_name": "Possenti", "given_name": "Andrea", "orcid": "0000-0001-5902-3731" }, { "family_name": "Poutanen", "given_name": "Juri", "orcid": "0000-0002-0983-0049" }, { "family_name": "Puccetti", "given_name": "Simonetta", "orcid": "0000-0002-2734-7835" }, { "family_name": "Ramsey", "given_name": "Brian D.", "orcid": "0000-0003-1548-1524" }, { "family_name": "Ratheesh", "given_name": "Ajay", "orcid": "0000-0003-0411-4243" }, { "family_name": "Sgr\u00f3", "given_name": "Carmelo", "orcid": "0000-0001-5676-6214" }, { "family_name": "Slane", "given_name": "Patrick", "orcid": "0000-0002-6986-6756" }, { "family_name": "Spandre", "given_name": "Gloria", "orcid": "0000-0003-0802-3453" }, { "family_name": "Tamagawa", "given_name": "Toru", "orcid": "0000-0002-8801-6263" }, { "family_name": "Tavecchio", "given_name": "Fabrizio", "orcid": "0000-0003-0256-0995" }, { "family_name": "Taverna", "given_name": "Roberto", "orcid": "0000-0002-1768-618X" }, { "family_name": "Tawara", "given_name": "Yuzuru" }, { "family_name": "Tennant", "given_name": "Allyn F.", "orcid": "0000-0002-9443-6774" }, { "family_name": "Thomas", "given_name": "Nicolas E." }, { "family_name": "Tombesi", "given_name": "Francesco", "orcid": "0000-0002-6562-8654" }, { "family_name": "Tsygankov", "given_name": "Sergey S.", "orcid": "0000-0002-9679-0793" }, { "family_name": "Turolla", "given_name": "Roberto", "orcid": "0000-0003-3977-8760" }, { "family_name": "Vink", "given_name": "Jacco", "orcid": "0000-0002-4708-4219" }, { "family_name": "Weisskopf", "given_name": "Martin C.", "orcid": "0000-0002-5270-4240" }, { "family_name": "Wu", "given_name": "Kinwah", "orcid": "0000-0002-7568-8765" }, { "family_name": "Zane", "given_name": "Silvia", "orcid": "0000-0001-5326-880X" } ], "abstract": "Pulsar wind nebulae are formed when outflows of relativistic electrons and positrons hit the surrounding supernova remnant or interstellar medium at a shock front. The Vela pulsar wind nebula is powered by a young pulsar (B0833-45, aged 11,000\u2009years) and located inside an extended structure called Vela X, which is itself inside the supernova remnant. Previous X-ray observations revealed two prominent arcs that are bisected by a jet and counter jet. Radio maps have shown high linear polarization of 60% in the outer regions of the nebula. Here we report an X-ray observation of the inner part of the nebula, where polarization can exceed 60% at the leading edge\u2014approaching the theoretical limit of what can be produced by synchrotron emission. We infer that, in contrast with the case of the supernova remnant, the electrons in the pulsar wind nebula are accelerated with little or no turbulence in a highly uniform magnetic field.", "doi": "10.1038/s41586-022-05476-5", "issn": "0028-0836", "publisher": "Nature Publishing Group", "publication": "Nature", "publication_date": "2022-12-22", "series_number": "7941", "volume": "612", "issue": "7941", "pages": "658-660" }, { "id": "authors:2v5vd-rf848", "collection": "authors", "collection_id": "2v5vd-rf848", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230302-365859100.9", "type": "article", "title": "Mapping the circumnuclear regions of the Circinus galaxy with the Imaging X-ray Polarimetry Explorer", "author": [ { "family_name": "Ursini", "given_name": "F.", "orcid": "0000-0001-9442-7897", "clpid": "Ursini-Francesco" }, { "family_name": "Marinucci", "given_name": "A.", "orcid": "0000-0002-2055-4946" }, { "family_name": "Matt", "given_name": "G.", "orcid": "0000-0002-2152-0916" }, { "family_name": "Bianchi", "given_name": "S.", "orcid": "0000-0002-4622-4240" }, { "family_name": "Marin", "given_name": "F.", "orcid": "0000-0003-4952-0835" }, { "family_name": "Marshall", "given_name": "H. L.", "orcid": "0000-0002-6492-1293" }, { "family_name": "Middei", "given_name": "R.", "orcid": "0000-0001-9815-9092" }, { "family_name": "Poutanen", "given_name": "J.", "orcid": "0000-0002-0983-0049" }, { "family_name": "Rogantini", "given_name": "D.", "orcid": "0000-0002-5359-9497" }, { "family_name": "De\u00a0Rosa", "given_name": "A.", "orcid": "0000-0001-5668-6863" }, { "family_name": "Di\u00a0Gesu", "given_name": "L.", "orcid": "0000-0002-5614-5028" }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Ingram", "given_name": "A.", "orcid": "0000-0002-5311-9078" }, { "family_name": "Kim", "given_name": "D. E.", "orcid": "0000-0001-5717-3736" }, { "family_name": "Krawczynski", "given_name": "H.", "orcid": "0000-0002-1084-6507" }, { "family_name": "Puccetti", "given_name": "S.", "orcid": "0000-0002-2734-7835" }, { "family_name": "Soffitta", "given_name": "P.", "orcid": "0000-0003-1252-4891" }, { "family_name": "Svoboda", "given_name": "J.", "orcid": "0000-0003-2931-0742" }, { "family_name": "Tombesi", "given_name": "F.", "orcid": "0000-0002-6562-8654" }, { "family_name": "Weisskopf", "given_name": "M. C.", "orcid": "0000-0002-5270-4240" }, { "family_name": "Barnouin", "given_name": "T.", "orcid": "0000-0003-1340-5675" }, { "family_name": "Perri", "given_name": "M.", "orcid": "0000-0003-3613-4409" }, { "family_name": "Podgorny", "given_name": "J.", "orcid": "0000-0001-5418-291X" }, { "family_name": "Ratheesh", "given_name": "A.", "orcid": "0000-0003-0411-4243" }, { "family_name": "Zaino", "given_name": "A." }, { "family_name": "Agudo", "given_name": "I.", "orcid": "0000-0002-3777-6182" }, { "family_name": "Antonelli", "given_name": "L. A.", "orcid": "0000-0002-5037-9034" }, { "family_name": "Bachetti", "given_name": "M.", "orcid": "0000-0002-4576-9337" }, { "family_name": "Baldini", "given_name": "L.", "orcid": "0000-0002-9785-7726" }, { "family_name": "Baumgartner", "given_name": "W. H.", "orcid": "0000-0002-5106-0463" }, { "family_name": "Bellazzini", "given_name": "R.", "orcid": "0000-0002-2469-7063" }, { "family_name": "Bongiorno", "given_name": "S. D.", "orcid": "0000-0002-0901-2097" }, { "family_name": "Bonino", "given_name": "R.", "orcid": "0000-0002-4264-1215" }, { "family_name": "Brez", "given_name": "A.", "orcid": "0000-0002-9460-1821" }, { "family_name": "Bucciantini", "given_name": "N.", "orcid": "0000-0002-8848-1392" }, { "family_name": "Capitanio", "given_name": "F.", "orcid": "0000-0002-6384-3027" }, { "family_name": "Castellano", "given_name": "S.", "orcid": "0000-0003-1111-4292" }, { "family_name": "Cavazzuti", "given_name": "E.", "orcid": "0000-0001-7150-9638" }, { "family_name": "Ciprini", "given_name": "S.", "orcid": "0000-0002-0712-2479" }, { "family_name": "Costa", "given_name": "E.", "orcid": "0000-0003-4925-8523" }, { "family_name": "Del\u00a0Monte", "given_name": "E.", "orcid": "0000-0002-3013-6334" }, { "family_name": "Di\u00a0Lalla", "given_name": "N.", "orcid": "0000-0002-7574-1298" }, { "family_name": "Di\u00a0Marco", "given_name": "A.", "orcid": "0000-0003-0331-3259" }, { "family_name": "Donnarumma", "given_name": "I.", "orcid": "0000-0002-4700-4549" }, { "family_name": "Doroshenko", "given_name": "V.", "orcid": "0000-0001-8162-1105" }, { "family_name": "Dov\u010diak", "given_name": "M.", "orcid": "0000-0003-0079-1239" }, { "family_name": "Ehlert", "given_name": "S. R.", "orcid": "0000-0003-4420-2838" }, { "family_name": "Enoto", "given_name": "T.", "orcid": "0000-0003-1244-3100" }, { "family_name": "Evangelista", "given_name": "Y.", "orcid": "0000-0001-6096-6710" }, { "family_name": "Fabiani", "given_name": "S.", "orcid": "0000-0003-1533-0283" }, { "family_name": "Ferrazzoli", "given_name": "R.", "orcid": "0000-0003-1074-8605" }, { "family_name": "Gunji", "given_name": "S.", "orcid": "0000-0002-5881-2445" }, { "family_name": "Heyl", "given_name": "J.", "orcid": "0000-0001-9739-367X" }, { "family_name": "Iwakiri", "given_name": "W.", "orcid": "0000-0002-0207-9010" }, { "family_name": "Jorstad", "given_name": "S. G.", "orcid": "0000-0001-6158-1708" }, { "family_name": "Karas", "given_name": "V.", "orcid": "0000-0002-5760-0459" }, { "family_name": "Kitaguchi", "given_name": "T." }, { "family_name": "Kolodziejczak", "given_name": "J. J.", "orcid": "0000-0002-0110-6136" }, { "family_name": "La\u00a0Monaca", "given_name": "F.", "orcid": "0000-0001-8916-4156" }, { "family_name": "Latronico", "given_name": "L.", "orcid": "0000-0002-0984-1856" }, { "family_name": "Liodakis", "given_name": "I.", "orcid": "0000-0001-9200-4006" }, { "family_name": "Maldera", "given_name": "S.", "orcid": "0000-0002-0698-4421" }, { "family_name": "Manfreda", "given_name": "A.", "orcid": "0000-0002-0998-4953" }, { "family_name": "Marscher", "given_name": "A. P.", "orcid": "0000-0001-7396-3332" }, { "family_name": "Mitsuishi", "given_name": "I." }, { "family_name": "Mizuno", "given_name": "T.", "orcid": "0000-0001-7263-0296" }, { "family_name": "Muleri", "given_name": "F.", "orcid": "0000-0003-3331-3794" }, { "family_name": "Ng", "given_name": "C. Y.", "orcid": "0000-0002-3616-5160" }, { "family_name": "O'Dell", "given_name": "S. L.", "orcid": "0000-0002-1868-8056" }, { "family_name": "Omodei", "given_name": "N.", "orcid": "0000-0002-5448-7577" }, { "family_name": "Oppedisano", "given_name": "C.", "orcid": "0000-0001-6194-4601" }, { "family_name": "Papitto", "given_name": "A.", "orcid": "0000-0001-6289-7413" }, { "family_name": "Pavlov", "given_name": "G. G.", "orcid": "0000-0002-7481-5259" }, { "family_name": "Peirson", "given_name": "A. L.", "orcid": "0000-0001-6292-1911" }, { "family_name": "Pesce-Rollins", "given_name": "M.", "orcid": "0000-0003-1790-8018" }, { "family_name": "Petrucci", "given_name": "P.-O.", "orcid": "0000-0001-6061-3480" }, { "family_name": "Pilia", "given_name": "M.", "orcid": "0000-0001-7397-8091" }, { "family_name": "Possenti", "given_name": "A.", "orcid": "0000-0001-5902-3731" }, { "family_name": "Ramsey", "given_name": "B. D.", "orcid": "0000-0003-1548-1524" }, { "family_name": "Rankin", "given_name": "J.", "orcid": "0000-0002-8111-1444" }, { "family_name": "Romani", "given_name": "R. W.", "orcid": "0000-0001-6711-3286" }, { "family_name": "Sgr\u00f2", "given_name": "C.", "orcid": "0000-0001-5676-6214" }, { "family_name": "Slane", "given_name": "P.", "orcid": "0000-0002-6986-6756" }, { "family_name": "Spandre", "given_name": "G.", "orcid": "0000-0003-0802-3453" }, { "family_name": "Tamagawa", "given_name": "T.", "orcid": "0000-0002-8801-6263" }, { "family_name": "Tavecchio", "given_name": "F.", "orcid": "0000-0003-0256-0995" }, { "family_name": "Taverna", "given_name": "R.", "orcid": "0000-0002-1768-618X" }, { "family_name": "Tawara", "given_name": "Y." }, { "family_name": "Tennant", "given_name": "A. F.", "orcid": "0000-0002-9443-6774" }, { "family_name": "Thomas", "given_name": "N. E.", "orcid": "0000-0003-0411-4606" }, { "family_name": "Trois", "given_name": "A.", "orcid": "0000-0002-3180-6002" }, { "family_name": "Tsygankov", "given_name": "S. S.", "orcid": "0000-0002-9679-0793" }, { "family_name": "Turolla", "given_name": "R.", "orcid": "0000-0003-3977-8760" }, { "family_name": "Vink", "given_name": "J.", "orcid": "0000-0002-4708-4219" }, { "family_name": "Wu", "given_name": "K.", "orcid": "0000-0002-7568-8765" }, { "family_name": "Xie", "given_name": "F.", "orcid": "0000-0002-0105-5826" }, { "family_name": "Zane", "given_name": "S.", "orcid": "0000-0001-5326-880X" } ], "abstract": "We report on the Imaging X-ray Polarimetry Explorer (IXPE) observation of the closest and X-ray brightest Compton-thick active galactic nucleus (AGN), the Circinus galaxy. We find the source to be significantly polarized in the 2\u20136\u00a0keV band. From previous studies, the X-ray spectrum is known to be dominated by reflection components, both neutral (torus) and ionized (ionization cones). Our analysis indicates that the polarization degree is 28\u00a0\u00b1\u00a07\u00a0per\u2009cent (at 68\u00a0per\u2009cent confidence level) for the neutral reflector, with a polarization angle of 18\u00b0 \u00b1 5\u00b0, roughly perpendicular to the radio jet. The polarization of the ionized reflection is unconstrained. A comparison with Monte Carlo simulations of the polarization expected from the torus shows that the neutral reflector is consistent with being an equatorial torus with a half-opening angle of 45\u00b0\u201355\u00b0. This is the first X-ray polarization detection in a Seyfert galaxy, demonstrating the power of X-ray polarimetry in probing the geometry of the circumnuclear regions of AGNs, and confirming the basic predictions of standard Unification Models.", "doi": "10.1093/mnras/stac3189", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2022-12-16", "series_number": "1", "volume": "519", "issue": "1", "pages": "50-58" }, { "id": "authors:9c2v7-4xh90", "collection": "authors", "collection_id": "9c2v7-4xh90", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230301-701033500.20", "type": "article", "title": "The X-Ray Polarimetry View of the Accreting Pulsar Cen X-3", "author": [ { "family_name": "Tsygankov", "given_name": "Sergey S.", "orcid": "0000-0002-9679-0793", "clpid": "Tsygankov-Sergey-S" }, { "family_name": "Doroshenko", "given_name": "Victor", "orcid": "0000-0001-8162-1105" }, { "family_name": "Poutanen", "given_name": "Juri", "orcid": "0000-0002-0983-0049" }, { "family_name": "Heyl", "given_name": "Jeremy", "orcid": "0000-0001-9739-367X" }, { "family_name": "Mushtukov", "given_name": "Alexander A.", "orcid": "0000-0003-2306-419X" }, { "family_name": "Caiazzo", "given_name": "Ilaria", "orcid": "0000-0002-4770-5388", "clpid": "Caiazzo-Ilaria" }, { "family_name": "Di Marco", "given_name": "Alessandro", "orcid": "0000-0003-0331-3259" }, { "family_name": "Forsblom", "given_name": "Sofia V.", "orcid": "0000-0001-9167-2790" }, { "family_name": "Gonz\u00e1lez-Caniulef", "given_name": "Denis", "orcid": "0000-0001-5848-0180" }, { "family_name": "Klawin", "given_name": "Moritz", "orcid": "0000-0001-9162-6639" }, { "family_name": "La Monaca", "given_name": "Fabio", "orcid": "0000-0001-8916-4156" }, { "family_name": "Malacaria", "given_name": "Christian", "orcid": "0000-0002-0380-0041" }, { "family_name": "Marshall", "given_name": "Herman L.", "orcid": "0000-0002-6492-1293" }, { "family_name": "Muleri", "given_name": "Fabio", "orcid": "0000-0003-3331-3794" }, { "family_name": "Ng", "given_name": "Mason", "orcid": "0000-0002-0940-6563" }, { "family_name": "Suleimanov", "given_name": "Valery F.", "orcid": "0000-0003-3733-7267" }, { "family_name": "Sunyaev", "given_name": "Rashid A.", "orcid": "0000-0002-2764-7192" }, { "family_name": "Turolla", "given_name": "Roberto", "orcid": "0000-0003-3977-8760" }, { "family_name": "Agudo", "given_name": "Iv\u00e1n", "orcid": "0000-0002-3777-6182" }, { "family_name": "Antonelli", "given_name": "Lucio A.", "orcid": "0000-0002-5037-9034" }, { "family_name": "Bachetti", "given_name": "Matteo", "orcid": "0000-0002-4576-9337" }, { "family_name": "Baldini", "given_name": "Luca", "orcid": "0000-0002-9785-7726" }, { "family_name": "Baumgartner", "given_name": "Wayne H.", "orcid": "0000-0002-5106-0463" }, { "family_name": "Bellazzini", "given_name": "Ronaldo", "orcid": "0000-0002-2469-7063" }, { "family_name": "Bianchi", "given_name": "Stefano", "orcid": "0000-0002-4622-4240" }, { "family_name": "Bongiorno", "given_name": "Stephen D.", "orcid": "0000-0002-0901-2097" }, { "family_name": "Bonino", "given_name": "Raffaella", "orcid": "0000-0002-4264-1215" }, { "family_name": "Brez", "given_name": "Alessandro", "orcid": "0000-0002-9460-1821" }, { "family_name": "Bucciantini", "given_name": "Niccol\u00f2", "orcid": "0000-0002-8848-1392" }, { "family_name": "Capitanio", "given_name": "Fiamma", "orcid": "0000-0002-6384-3027" }, { "family_name": "Castellano", "given_name": "Simone", "orcid": "0000-0003-1111-4292" }, { "family_name": "Cavazzuti", "given_name": "Elisabetta", "orcid": "0000-0001-7150-9638" }, { "family_name": "Ciprini", "given_name": "Stefano", "orcid": "0000-0002-0712-2479" }, { "family_name": "Costa", "given_name": "Enrico", "orcid": "0000-0003-4925-8523" }, { "family_name": "De Rosa", "given_name": "Alessandra", "orcid": "0000-0001-5668-6863" }, { "family_name": "Del Monte", "given_name": "Ettore", "orcid": "0000-0002-3013-6334" }, { "family_name": "Gesu", "given_name": "Laura Di", "orcid": "0000-0002-5614-5028" }, { "family_name": "Lalla", "given_name": "Niccol\u00f2 Di", "orcid": "0000-0002-7574-1298" }, { "family_name": "Donnarumma", "given_name": "Immacolata", "orcid": "0000-0002-4700-4549" }, { "family_name": "Dov\u010diak", "given_name": "Michal", "orcid": "0000-0003-0079-1239" }, { "family_name": "Enoto", "given_name": "Teruaki", "orcid": "0000-0003-1244-3100" }, { "family_name": "Evangelista", "given_name": "Yuri", "orcid": "0000-0001-6096-6710" }, { "family_name": "Fabiani", "given_name": "Sergio", "orcid": "0000-0003-1533-0283" }, { "family_name": "Ferrazzoli", "given_name": "Riccardo", "orcid": "0000-0003-1074-8605" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Gunji", "given_name": "Shuichi", "orcid": "0000-0002-5881-2445" }, { "family_name": "Hayashida", "given_name": "Kiyoshi", "orcid": "0000-0002-0110-6136" }, { "family_name": "Iwakiri", "given_name": "Wataru", "orcid": "0000-0002-0207-9010" }, { "family_name": "Jorstad", "given_name": "Svetlana G.", "orcid": "0000-0001-6158-1708" }, { "family_name": "Karas", "given_name": "Vladimir", "orcid": "0000-0002-5760-0459" }, { "family_name": "Kitaguchi", "given_name": "Takao" }, { "family_name": "Krawczynski", "given_name": "Henric", "orcid": "0000-0002-1084-6507" }, { "family_name": "Latronico", "given_name": "Luca", "orcid": "0000-0002-0984-1856" }, { "family_name": "Liodakis", "given_name": "Ioannis", "orcid": "0000-0001-9200-4006" }, { "family_name": "Maldera", "given_name": "Simone", "orcid": "0000-0002-0698-4421" }, { "family_name": "Manfreda", "given_name": "Alberto", "orcid": "0000-0002-0998-4953" }, { "family_name": "Marin", "given_name": "Fr\u00e9d\u00e9ric", "orcid": "0000-0003-4952-0835" }, { "family_name": "Marinucci", "given_name": "Andrea", "orcid": "0000-0002-2055-4946" }, { "family_name": "Marscher", "given_name": "Alan P.", "orcid": "0000-0001-7396-3332" }, { "family_name": "Matt", "given_name": "Giorgio", "orcid": "0000-0002-2152-0916" }, { "family_name": "Mitsuishi", "given_name": "Ikuyuki" }, { "family_name": "Mizuno", "given_name": "Tsunefumi", "orcid": "0000-0001-7263-0296" }, { "family_name": "Ng", "given_name": "Chi-Yung", "orcid": "0000-0002-5847-2612" }, { "family_name": "O'Dell", "given_name": "Stephen L.", "orcid": "0000-0002-1868-8056" }, { "family_name": "Omodei", "given_name": "Nicola", "orcid": "0000-0002-5448-7577" }, { "family_name": "Oppedisano", "given_name": "Chiara", "orcid": "0000-0001-6194-4601" }, { "family_name": "Papitto", "given_name": "Alessandro", "orcid": "0000-0001-6289-7413" }, { "family_name": "Pavlov", "given_name": "George G.", "orcid": "0000-0002-7481-5259" }, { "family_name": "Peirson", "given_name": "Abel L.", "orcid": "0000-0001-6292-1911" }, { "family_name": "Perri", "given_name": "Matteo", "orcid": "0000-0003-3613-4409" }, { "family_name": "Pesce-Rollins", "given_name": "Melissa", "orcid": "0000-0003-1790-8018" }, { "family_name": "Petrucci", "given_name": "Pierre-Olivier", "orcid": "0000-0001-6061-3480" }, { "family_name": "Pilia", "given_name": "Maura", "orcid": "0000-0001-7397-8091" }, { "family_name": "Possenti", "given_name": "Andrea", "orcid": "0000-0001-5902-3731" }, { "family_name": "Puccetti", "given_name": "Simonetta", "orcid": "0000-0002-2734-7835" }, { "family_name": "Ramsey", "given_name": "Brian D.", "orcid": "0000-0003-1548-1524" }, { "family_name": "Rankin", "given_name": "John", "orcid": "0000-0002-9774-0560" }, { "family_name": "Ratheesh", "given_name": "Ajay", "orcid": "0000-0003-0411-4243" }, { "family_name": "Romani", "given_name": "Roger W.", "orcid": "0000-0001-6711-3286" }, { "family_name": "Sgr\u00f2", "given_name": "Carmelo", "orcid": "0000-0001-5676-6214" }, { "family_name": "Slane", "given_name": "Patrick", "orcid": "0000-0002-6986-6756" }, { "family_name": "Soffitta", "given_name": "Paolo", "orcid": "0000-0002-7781-4104" }, { "family_name": "Spandre", "given_name": "Gloria", "orcid": "0000-0003-0802-3453" }, { "family_name": "Tamagawa", "given_name": "Toru", "orcid": "0000-0002-8801-6263" }, { "family_name": "Tavecchio", "given_name": "Fabrizio", "orcid": "0000-0003-0256-0995" }, { "family_name": "Taverna", "given_name": "Roberto", "orcid": "0000-0002-1768-618X" }, { "family_name": "Tawara", "given_name": "Yuzuru" }, { "family_name": "Tennant", "given_name": "Allyn F.", "orcid": "0000-0002-9443-6774" }, { "family_name": "Thomas", "given_name": "Nicholas E.", "orcid": "0000-0003-0411-4606" }, { "family_name": "Tombesi", "given_name": "Francesco", "orcid": "0000-0002-6562-8654" }, { "family_name": "Trois", "given_name": "Alessio", "orcid": "0000-0002-3180-6002" }, { "family_name": "Weisskopf", "given_name": "Martin C.", "orcid": "0000-0002-5270-4240" }, { "family_name": "Wu", "given_name": "Kinwah", "orcid": "0000-0002-7568-8765" }, { "family_name": "Xie", "given_name": "Fei", "orcid": "0000-0002-0105-5826" }, { "family_name": "Zane", "given_name": "Silvia", "orcid": "0000-0001-5326-880X" } ], "abstract": "The first X-ray pulsar, Cen X-3, was discovered 50 yr ago. Radiation from such objects is expected to be highly polarized due to birefringence of plasma and vacuum associated with propagation of photons in the presence of the strong magnetic field. Here we present results of the observations of Cen X-3 performed with the Imaging X-ray Polarimetry Explorer. The source exhibited significant flux variability and was observed in two states different by a factor of \u223c20 in flux. In the low-luminosity state, no significant polarization was found in either pulse phase-averaged (with a 3\u03c3 upper limit of 12%) or phase-resolved (the 3\u03c3 upper limits are 20%\u201330%) data. In the bright state, the polarization degree of 5.8% \u00b1 0.3% and polarization angle of 49.\u00b06 \u00b1 1.\u00b05 with a significance of about 20\u03c3 were measured from the spectropolarimetric analysis of the phase-averaged data. The phase-resolved analysis showed a significant anticorrelation between the flux and the polarization degree, as well as strong variations of the polarization angle. The fit with the rotating vector model indicates a position angle of the pulsar spin axis of about 49\u00b0 and a magnetic obliquity of 17\u00b0. The detected relatively low polarization can be explained if the upper layers of the neutron star surface are overheated by the accreted matter and the conversion of the polarization modes occurs within the transition region between the upper hot layer and a cooler underlying atmosphere. A fraction of polarization signal can also be produced by reflection of radiation from the neutron star surface and the accretion curtain.", "doi": "10.3847/2041-8213/aca486", "issn": "2041-8205", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal Letters", "publication_date": "2022-12-10", "series_number": "1", "volume": "941", "issue": "1", "pages": "Art. No. L14" }, { "id": "authors:mb3ja-v5e51", "collection": "authors", "collection_id": "mb3ja-v5e51", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230203-893210800.24", "type": "article", "title": "NuSTAR Spectral Analysis beyond 79 keV with Stray Light", "author": [ { "family_name": "Mastroserio", "given_name": "G.", "orcid": "0000-0003-4216-7936", "clpid": "Mastroserio-Guglielmo" }, { "family_name": "Grefenstette", "given_name": "B. W.", "orcid": "0000-0002-1984-2932", "clpid": "Grefenstette-Brian-W" }, { "family_name": "Thalhammer", "given_name": "P.", "orcid": "0000-0001-6269-2821", "clpid": "Thalhammer-Philipp" }, { "family_name": "Buisson", "given_name": "D. J. K.", "orcid": "0000-0002-5341-6929", "clpid": "Buisson-Douglas-J-K" }, { "family_name": "Brumback", "given_name": "M. C.", "orcid": "0000-0002-4024-6967", "clpid": "Brumback-McKinley-C" }, { "family_name": "Ludlam", "given_name": "R. M.", "orcid": "0000-0002-8961-939X", "clpid": "Ludlam-Renee-M" }, { "family_name": "Connors", "given_name": "R. M. T.", "orcid": "0000-0002-8908-759X", "clpid": "Connors-Riley-M-T" }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Grinberg", "given_name": "V.", "orcid": "0000-0003-2538-0188", "clpid": "Grinberg-Victoria" }, { "family_name": "Madsen", "given_name": "K. K.", "orcid": "0000-0003-1252-4891", "clpid": "Madsen-Kristin-K" }, { "family_name": "Miyasaka", "given_name": "H.", "orcid": "0000-0002-8074-4186", "clpid": "Miyasaka-Hiromasa" }, { "family_name": "Tomsick", "given_name": "J. A.", "orcid": "0000-0001-5506-9855", "clpid": "Tomsick-John-A" }, { "family_name": "Wilms", "given_name": "J.", "orcid": "0000-0003-2065-5410", "clpid": "Wilms-J\u00f6rn" } ], "abstract": "Due to the structure of the NuSTAR telescope, photons at a large off axis (>1\u00b0) can reach the detectors directly (stray light), without passing through the instrument optics. At these off-axis angles NuSTAR essentially turns into a collimated instrument and the spectrum can extend to energies above the Pt K edge (79 keV) of the multilayers, which limits the effective area bandpass of the optics. We present the first scientific spectral analysis beyond 79 keV using a Cygnus X-1 observation in StrayCats: the catalog of stray light observations. This serendipitous stray light observation occurred simultaneously with an INTEGRAL observation. When the spectra are modeled together in the 30\u2013120 keV energy band, we find that the NuSTAR stray light flux is well calibrated and constrained to be consistent with the INTEGRAL flux at the 90% confidence level. Furthermore, we explain how to treat the background of the stray light spectral analysis, which is especially important at high energies.", "doi": "10.3847/1538-4357/ac8c94", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2022-12-10", "series_number": "1", "volume": "941", "issue": "1", "pages": "Art. No. 35" }, { "id": "authors:1aqnx-1j226", "collection": "authors", "collection_id": "1aqnx-1j226", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20221107-999291600.31", "type": "article", "title": "Determination of X-ray pulsar geometry with IXPE polarimetry", "author": [ { "family_name": "Doroshenko", "given_name": "Victor", "orcid": "0000-0001-8162-1105", "clpid": "Doroshenko-Victor" }, { "family_name": "Poutanen", "given_name": "Juri", "orcid": "0000-0002-0983-0049" }, { "family_name": "Tsygankov", "given_name": "Sergey S.", "orcid": "0000-0002-9679-0793" }, { "family_name": "Suleimanov", "given_name": "Valery F.", "orcid": "0000-0003-3733-7267" }, { "family_name": "Bachetti", "given_name": "Matteo", "orcid": "0000-0002-4576-9337" }, { "family_name": "Caiazzo", "given_name": "Ilaria", "orcid": "0000-0002-4770-5388", "clpid": "Caiazzo-Ilaria" }, { "family_name": "Costa", "given_name": "Enrico", "orcid": "0000-0003-4925-8523" }, { "family_name": "Di Marco", "given_name": "Alessandro", "orcid": "0000-0003-0331-3259" }, { "family_name": "Heyl", "given_name": "Jeremy", "orcid": "0000-0001-9739-367X" }, { "family_name": "La Monaca", "given_name": "Fabio", "orcid": "0000-0001-8916-4156" }, { "family_name": "Muleri", "given_name": "Fabio", "orcid": "0000-0003-3331-3794" }, { "family_name": "Mushtukov", "given_name": "Alexander A." }, { "family_name": "Pavlov", "given_name": "George G.", "orcid": "0000-0002-7481-5259" }, { "family_name": "Ramsey", "given_name": "Brian D." }, { "family_name": "Rankin", "given_name": "John", "orcid": "0000-0002-9774-0560" }, { "family_name": "Santangelo", "given_name": "Andrea", "orcid": "0000-0003-4187-9560" }, { "family_name": "Soffitta", "given_name": "Paolo", "orcid": "0000-0002-7781-4104" }, { "family_name": "Staubert", "given_name": "R\u00fcdiger", "orcid": "0000-0003-1498-1543" }, { "family_name": "Weisskopf", "given_name": "Martin C.", "orcid": "0000-0002-5270-4240" }, { "family_name": "Zane", "given_name": "Silvia" }, { "family_name": "Agudo", "given_name": "Iv\u00e1n", "orcid": "0000-0002-3777-6182" }, { "family_name": "Antonelli", "given_name": "Lucio A." }, { "family_name": "Baldini", "given_name": "Luca", "orcid": "0000-0002-9785-7726" }, { "family_name": "Baumgartner", "given_name": "Wayne H." }, { "family_name": "Bellazzini", "given_name": "Ronaldo", "orcid": "0000-0002-2469-7063" }, { "family_name": "Bianchi", "given_name": "Stefano", "orcid": "0000-0002-4622-4240" }, { "family_name": "Bongiorno", "given_name": "Stephen D." }, { "family_name": "Bonino", "given_name": "Raffaella", "orcid": "0000-0002-4264-1215" }, { "family_name": "Brez", "given_name": "Alessandro" }, { "family_name": "Bucciantini", "given_name": "Niccol\u00f2", "orcid": "0000-0002-8848-1392" }, { "family_name": "Capitanio", "given_name": "Fiamma", "orcid": "0000-0002-6384-3027" }, { "family_name": "Castellano", "given_name": "Simone", "orcid": "0000-0003-1111-4292" }, { "family_name": "Cavazzuti", "given_name": "Elisabetta", "orcid": "0000-0001-7150-9638" }, { "family_name": "Ciprini", "given_name": "Stefano", "orcid": "0000-0002-0712-2479" }, { "family_name": "De Rosa", "given_name": "Alessandra", "orcid": "0000-0001-5668-6863" }, { "family_name": "Del Monte", "given_name": "Ettore", "orcid": "0000-0002-3013-6334" }, { "family_name": "Di Gesu", "given_name": "Laura" }, { "family_name": "Di Lalla", "given_name": "Niccol\u00f2", "orcid": "0000-0002-7574-1298" }, { "family_name": "Donnarumma", "given_name": "Immacolata", "orcid": "0000-0002-4700-4549" }, { "family_name": "Dov\u010diak", "given_name": "Michal", "orcid": "0000-0003-0079-1239" }, { "family_name": "Ehlert", "given_name": "Steven R.", "orcid": "0000-0003-4420-2838" }, { "family_name": "Enoto", "given_name": "Teruaki", "orcid": "0000-0003-1244-3100" }, { "family_name": "Evangelista", "given_name": "Yuri", "orcid": "0000-0001-6096-6710" }, { "family_name": "Fabiani", "given_name": "Sergio", "orcid": "0000-0003-1533-0283" }, { "family_name": "Ferrazzoli", "given_name": "Riccardo", "orcid": "0000-0003-1074-8605" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Gunji", "given_name": "Shuichi", "orcid": "0000-0002-5881-2445" }, { "family_name": "Hayashida", "given_name": "Kiyoshi" }, { "family_name": "Iwakiri", "given_name": "Wataru", "orcid": "0000-0002-0207-9010" }, { "family_name": "Jorstad", "given_name": "Svetlana G.", "orcid": "0000-0001-6158-1708" }, { "family_name": "Karas", "given_name": "Vladimir", "orcid": "0000-0002-5760-0459" }, { "family_name": "Kitaguchi", "given_name": "Takao" }, { "family_name": "Kolodziejczak", "given_name": "Jeffery J." }, { "family_name": "Krawczynski", "given_name": "Henric", "orcid": "0000-0002-1084-6507" }, { "family_name": "Latronico", "given_name": "Luca", "orcid": "0000-0002-0984-1856" }, { "family_name": "Liodakis", "given_name": "Ioannis", "orcid": "0000-0001-9200-4006" }, { "family_name": "Maldera", "given_name": "Simone", "orcid": "0000-0002-0698-4421" }, { "family_name": "Manfreda", "given_name": "Alberto", "orcid": "0000-0002-0998-4953" }, { "family_name": "Marin", "given_name": "Fr\u00e9d\u00e9ric", "orcid": "0000-0003-4952-0835" }, { "family_name": "Marinucci", "given_name": "Andrea", "orcid": "0000-0002-2055-4946" }, { "family_name": "Marscher", "given_name": "Alan P.", "orcid": "0000-0001-7396-3332" }, { "family_name": "Marshall", "given_name": "Herman L.", "orcid": "0000-0002-6492-1293" }, { "family_name": "Matt", "given_name": "Giorgio", "orcid": "0000-0002-2152-0916" }, { "family_name": "Mitsuishi", "given_name": "Ikuyuki" }, { "family_name": "Mizuno", "given_name": "Tsunefumi", "orcid": "0000-0001-7263-0296" }, { "family_name": "Ng", "given_name": "Chi-Yung", "orcid": "0000-0002-5847-2612" }, { "family_name": "O'Dell", "given_name": "Stephen L.", "orcid": "0000-0002-1868-8056" }, { "family_name": "Omodei", "given_name": "Nicola", "orcid": "0000-0002-5448-7577" }, { "family_name": "Oppedisano", "given_name": "Chiara", "orcid": "0000-0001-6194-4601" }, { "family_name": "Papitto", "given_name": "Alessandro", "orcid": "0000-0001-6289-7413" }, { "family_name": "Peirson", "given_name": "Abel L.", "orcid": "0000-0001-6292-1911" }, { "family_name": "Perri", "given_name": "Matteo", "orcid": "0000-0003-3613-4409" }, { "family_name": "Pesce-Rollins", "given_name": "Melissa", "orcid": "0000-0003-1790-8018" }, { "family_name": "Pilia", "given_name": "Maura", "orcid": "0000-0001-7397-8091" }, { "family_name": "Possenti", "given_name": "Andrea", "orcid": "0000-0001-5902-3731" }, { "family_name": "Puccetti", "given_name": "Simonetta", "orcid": "0000-0002-2734-7835" }, { "family_name": "Ratheesh", "given_name": "Ajay" }, { "family_name": "Romani", "given_name": "Roger W.", "orcid": "0000-0001-6711-3286" }, { "family_name": "Sgr\u00f2", "given_name": "Carmelo", "orcid": "0000-0001-5676-6214" }, { "family_name": "Slane", "given_name": "Patrick", "orcid": "0000-0002-6986-6756" }, { "family_name": "Spandre", "given_name": "Gloria", "orcid": "0000-0003-0802-3453" }, { "family_name": "Sunyaev", "given_name": "Rashid A." }, { "family_name": "Tamagawa", "given_name": "Toru", "orcid": "0000-0002-8801-6263" }, { "family_name": "Tavecchio", "given_name": "Fabrizio", "orcid": "0000-0003-0256-0995" }, { "family_name": "Taverna", "given_name": "Roberto", "orcid": "0000-0002-1768-618X" }, { "family_name": "Tawara", "given_name": "Yuzuru" }, { "family_name": "Tennant", "given_name": "Allyn F." }, { "family_name": "Thomas", "given_name": "Nicolas E." }, { "family_name": "Tombesi", "given_name": "Francesco", "orcid": "0000-0002-6562-8654" }, { "family_name": "Trois", "given_name": "Alessio", "orcid": "0000-0002-3180-6002" }, { "family_name": "Turolla", "given_name": "Roberto", "orcid": "0000-0003-3977-8760" }, { "family_name": "Vink", "given_name": "Jacco", "orcid": "0000-0002-4708-4219" }, { "family_name": "Wu", "given_name": "Kinwah" }, { "family_name": "Xie", "given_name": "Fei" } ], "abstract": "Using observations of X-ray pulsar Hercules X-1 by the Imaging X-ray Polarimetry Explorer we report a highly significant (>17\u03c3) detection of the polarization signal from an accreting neutron star. The observed degree of linear polarization of ~10% is far below theoretical expectations for this object, and stays low throughout the spin cycle of the pulsar. Both the degree and angle of polarization exhibit variability with the pulse phase, allowing us to measure the pulsar spin position angle 57(2)\u2009deg and the magnetic obliquity 12(4)\u2009deg, which is an essential step towards detailed modelling of the intrinsic emission of X-ray pulsars. Combining our results with the optical polarimetric data, we find that the spin axis of the neutron star and the angular momentum of the binary orbit are misaligned by at least ~20\u2009deg, which is a strong argument in support of the models explaining the stability of the observed superorbital variability with the precession of the neutron star.", "doi": "10.1038/s41550-022-01799-5", "issn": "2397-3366", "publisher": "Nature Publishing Group", "publication": "Nature Astronomy", "publication_date": "2022-12", "series_number": "12", "volume": "6", "issue": "12", "pages": "1433-1443" }, { "id": "authors:99bvb-e7812", "collection": "authors", "collection_id": "99bvb-e7812", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20221212-796684400.32", "type": "article", "title": "Polarized blazar X-rays imply particle acceleration in shocks", "author": [ { "family_name": "Liodakis", "given_name": "Ioannis", "orcid": "0000-0001-9200-4006", "clpid": "Liodakis-Ioannis" }, { "family_name": "Marscher", "given_name": "Alan P.", "orcid": "0000-0001-7396-3332" }, { "family_name": "Agudo", "given_name": "Iv\u00e1n", "orcid": "0000-0002-3777-6182" }, { "family_name": "Berdyugin", "given_name": "Andrei V.", "orcid": "0000-0002-9353-5164" }, { "family_name": "Bernardos", "given_name": "Maria I.", "orcid": "0000-0001-8872-1168" }, { "family_name": "Bonnoli", "given_name": "Giacomo", "orcid": "0000-0003-2464-9077" }, { "family_name": "Borman", "given_name": "George A." }, { "family_name": "Casadio", "given_name": "Carolina", "orcid": "0000-0003-1117-2863" }, { "family_name": "Casanova", "given_name": "V\u0131\u0301ctor" }, { "family_name": "Cavazzuti", "given_name": "Elisabetta", "orcid": "0000-0001-7150-9638" }, { "family_name": "Rodriguez Cavero", "given_name": "Nicole", "orcid": "0000-0001-5256-0278" }, { "family_name": "Di Gesu", "given_name": "Laura", "orcid": "0000-0002-5614-5028" }, { "family_name": "Di Lalla", "given_name": "Niccol\u00f3", "orcid": "0000-0002-7574-1298" }, { "family_name": "Donnarumma", "given_name": "Immacolata", "orcid": "0000-0002-4700-4549" }, { "family_name": "Ehlert", "given_name": "Steven R.", "orcid": "0000-0003-4420-2838" }, { "family_name": "Errando", "given_name": "Manel", "orcid": "0000-0002-1853-863X" }, { "family_name": "Escudero", "given_name": "Juan", "orcid": "0000-0002-4131-655X" }, { "family_name": "Garc\u0131\u0301a-Comas", "given_name": "Maya", "orcid": "0000-0003-2323-4486" }, { "family_name": "Ag\u0131\u0301s-Gonz\u00e1lez", "given_name": "Beatriz", "orcid": "0000-0001-7702-8931" }, { "family_name": "Husillos", "given_name": "C\u00e9sar", "orcid": "0000-0001-8286-5443" }, { "family_name": "Jormanainen", "given_name": "Jenni", "orcid": "0000-0003-4519-7751" }, { "family_name": "Jorstad", "given_name": "Svetlana G.", "orcid": "0000-0001-6158-1708" }, { "family_name": "Kagitani", "given_name": "Masato", "orcid": "0000-0002-4115-7122" }, { "family_name": "Kopatskaya", "given_name": "Evgenia N.", "orcid": "0000-0001-9518-337X" }, { "family_name": "Kravtsov", "given_name": "Vadim", "orcid": "0000-0002-7502-3173" }, { "family_name": "Krawczynski", "given_name": "Henric", "orcid": "0000-0002-1084-6507" }, { "family_name": "Lindfors", "given_name": "Elina", "orcid": "0000-0002-9155-6199" }, { "family_name": "Larionova", "given_name": "Elena G.", "orcid": "0000-0002-2471-6500" }, { "family_name": "Madejski", "given_name": "Grzegorz M." }, { "family_name": "Marin", "given_name": "Fr\u00e9d\u00e9ric", "orcid": "0000-0003-4952-0835" }, { "family_name": "Marchini", "given_name": "Alessandro", "orcid": "0000-0003-3779-6762" }, { "family_name": "Marshall", "given_name": "Herman L.", "orcid": "0000-0002-6492-1293" }, { "family_name": "Morozova", "given_name": "Daria A.", "orcid": "0000-0002-9407-7804" }, { "family_name": "Massaro", "given_name": "Francesco", "orcid": "0000-0002-1704-9850" }, { "family_name": "Masiero", "given_name": "Joseph R.", "orcid": "0000-0003-2638-720X", "clpid": "Masiero-Joseph-R" }, { "family_name": "Mawet", "given_name": "Dimitri", "orcid": "0000-0002-8895-4735", "clpid": "Mawet-D" }, { "family_name": "Middei", "given_name": "Riccardo", "orcid": "0000-0001-9815-9092" }, { "family_name": "Millar-Blanchaer", "given_name": "Maxwell A.", "orcid": "0000-0001-6205-9233" }, { "family_name": "Myserlis", "given_name": "Ioannis", "orcid": "0000-0003-3025-9497" }, { "family_name": "Negro", "given_name": "Michela", "orcid": "0000-0002-6548-5622" }, { "family_name": "Nilsson", "given_name": "Kari", "orcid": "0000-0002-1445-8683" }, { "family_name": "O'Dell", "given_name": "Stephen L.", "orcid": "0000-0002-1868-8056" }, { "family_name": "Omodei", "given_name": "Nicola", "orcid": "0000-0002-5448-7577" }, { "family_name": "Pacciani", "given_name": "Luigi", "orcid": "0000-0001-6897-5996" }, { "family_name": "Paggi", "given_name": "Alessandro", "orcid": "0000-0002-5646-2410" }, { "family_name": "Panopoulou", "given_name": "Georgia V.", "orcid": "0000-0001-7482-5759", "clpid": "Panopoulou-Georgia-V" }, { "family_name": "Peirson", "given_name": "Abel L.", "orcid": "0000-0001-6292-1911" }, { "family_name": "Perri", "given_name": "Matteo", "orcid": "0000-0003-3613-4409" }, { "family_name": "Petrucci", "given_name": "Pierre-Olivier", "orcid": "0000-0001-6061-3480" }, { "family_name": "Poutanen", "given_name": "Juri", "orcid": "0000-0002-0983-0049" }, { "family_name": "Puccetti", "given_name": "Simonetta", "orcid": "0000-0002-2734-7835" }, { "family_name": "Romani", "given_name": "Roger W.", "orcid": "0000-0001-6711-3286" }, { "family_name": "Sakanoi", "given_name": "Takeshi", "orcid": "0000-0002-7146-9020" }, { "family_name": "Savchenko", "given_name": "Sergey S.", "orcid": "0000-0003-4147-3851" }, { "family_name": "Sota", "given_name": "Alfredo", "orcid": "0000-0002-9404-6952" }, { "family_name": "Tavecchio", "given_name": "Fabrizio", "orcid": "0000-0003-0256-0995" }, { "family_name": "Tinyanont", "given_name": "Samaporn" }, { "family_name": "Vasilyev", "given_name": "Andrey A.", "orcid": "0000-0002-8293-0214" }, { "family_name": "Weaver", "given_name": "Zachary R.", "orcid": "0000-0001-6314-0690" }, { "family_name": "Zhovtan", "given_name": "Alexey V." }, { "family_name": "Antonelli", "given_name": "Lucio A.", "orcid": "0000-0002-5037-9034" }, { "family_name": "Bachetti", "given_name": "Matteo", "orcid": "0000-0002-4576-9337" }, { "family_name": "Baldini", "given_name": "Luca", "orcid": "0000-0002-9785-7726" }, { "family_name": "Baumgartner", "given_name": "Wayne H.", "orcid": "0000-0002-5106-0463" }, { "family_name": "Bellazzini", "given_name": "Ronaldo", "orcid": "0000-0002-2469-7063" }, { "family_name": "Bianchi", "given_name": "Stefano", "orcid": "0000-0002-4622-4240" }, { "family_name": "Bongiorno", "given_name": "Stephen D.", "orcid": "0000-0002-0901-2097" }, { "family_name": "Bonino", "given_name": "Raffaella", "orcid": "0000-0002-4264-1215" }, { "family_name": "Brez", "given_name": "Alessandro", "orcid": "0000-0002-9460-1821" }, { "family_name": "Bucciantini", "given_name": "Niccol\u00f2", "orcid": "0000-0002-8848-1392" }, { "family_name": "Capitanio", "given_name": "Fiamma", "orcid": "0000-0002-6384-3027" }, { "family_name": "Castellano", "given_name": "Simone", "orcid": "0000-0003-1111-4292" }, { "family_name": "Ciprini", "given_name": "Stefano", "orcid": "0000-0002-0712-2479" }, { "family_name": "Costa", "given_name": "Enrico", "orcid": "0000-0003-4925-8523" }, { "family_name": "De Rosa", "given_name": "Alessandra", "orcid": "0000-0001-5668-6863" }, { "family_name": "Del Monte", "given_name": "Ettore", "orcid": "0000-0002-3013-6334" }, { "family_name": "Di Marco", "given_name": "Alessandro", "orcid": "0000-0003-0331-3259" }, { "family_name": "Doroshenko", "given_name": "Victor", "orcid": "0000-0001-8162-1105" }, { "family_name": "Dov\u010diak", "given_name": "Michal", "orcid": "0000-0003-0079-1239" }, { "family_name": "Enoto", "given_name": "Teruaki", "orcid": "0000-0003-1244-3100" }, { "family_name": "Evangelista", "given_name": "Yuri", "orcid": "0000-0001-6096-6710" }, { "family_name": "Fabiani", "given_name": "Sergio", "orcid": "0000-0003-1533-0283" }, { "family_name": "Ferrazzoli", "given_name": "Riccardo", "orcid": "0000-0003-1074-8605" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Gunji", "given_name": "Shuichi", "orcid": "0000-0002-5881-2445" }, { "family_name": "Hayashida", "given_name": "Kiyoshi", "orcid": "0000-0002-0110-6136" }, { "family_name": "Heyl", "given_name": "Jeremy", "orcid": "0000-0001-9739-367X" }, { "family_name": "Iwakiri", "given_name": "Wataru", "orcid": "0000-0002-0207-9010" }, { "family_name": "Karas", "given_name": "Vladimir", "orcid": "0000-0002-5760-0459" }, { "family_name": "Kitaguchi", "given_name": "Takao" }, { "family_name": "La Monaca", "given_name": "Fabio", "orcid": "0000-0001-8916-4156" }, { "family_name": "Latronico", "given_name": "Luca", "orcid": "0000-0002-0984-1856" }, { "family_name": "Maldera", "given_name": "Simone", "orcid": "0000-0002-0698-4421" }, { "family_name": "Manfreda", "given_name": "Alberto", "orcid": "0000-0002-0998-4953" }, { "family_name": "Marinucci", "given_name": "Andrea", "orcid": "0000-0002-2055-4946" }, { "family_name": "Matt", "given_name": "Giorgio", "orcid": "0000-0002-2152-0916" }, { "family_name": "Mitsuishi", "given_name": "Ikuyuki" }, { "family_name": "Mizuno", "given_name": "Tsunefumi", "orcid": "0000-0001-7263-0296" }, { "family_name": "Muleri", "given_name": "Fabio", "orcid": "0000-0003-3331-3794" }, { "family_name": "Ng", "given_name": "Stephen C.-Y.", "orcid": "0000-0002-5847-2612" }, { "family_name": "Oppedisano", "given_name": "Chiara", "orcid": "0000-0001-6194-4601" }, { "family_name": "Papitto", "given_name": "Alessandro", "orcid": "0000-0001-6289-7413" }, { "family_name": "Pavlov", "given_name": "George G.", "orcid": "0000-0002-7481-5259" }, { "family_name": "Pesce-Rollins", "given_name": "Melissa", "orcid": "0000-0003-1790-8018" }, { "family_name": "Pilia", "given_name": "Maura", "orcid": "0000-0001-7397-8091" }, { "family_name": "Possenti", "given_name": "Andrea", "orcid": "0000-0001-5902-3731" }, { "family_name": "Ramsey", "given_name": "Brian D.", "orcid": "0000-0003-1548-1524" }, { "family_name": "Rankin", "given_name": "John", "orcid": "0000-0002-9774-0560" }, { "family_name": "Ratheesh", "given_name": "Ajay", "orcid": "0000-0003-0411-4243" }, { "family_name": "Sgr\u00f3", "given_name": "Carmelo", "orcid": "0000-0001-5676-6214" }, { "family_name": "Slane", "given_name": "Patrick", "orcid": "0000-0002-6986-6756" }, { "family_name": "Soffitta", "given_name": "Paolo", "orcid": "0000-0002-7781-4104" }, { "family_name": "Spandre", "given_name": "Gloria", "orcid": "0000-0003-0802-3453" }, { "family_name": "Tamagawa", "given_name": "Toru", "orcid": "0000-0002-8801-6263" }, { "family_name": "Taverna", "given_name": "Roberto", "orcid": "0000-0002-1768-618X" }, { "family_name": "Tawara", "given_name": "Yuzuru" }, { "family_name": "Tennant", "given_name": "Allyn F.", "orcid": "0000-0002-9443-6774" }, { "family_name": "Thomas", "given_name": "Nicolas E." }, { "family_name": "Tombesi", "given_name": "Francesco", "orcid": "0000-0002-6562-8654" }, { "family_name": "Trois", "given_name": "Alessio", "orcid": "0000-0002-3180-6002" }, { "family_name": "Tsygankov", "given_name": "Sergey", "orcid": "0000-0002-9679-0793" }, { "family_name": "Turolla", "given_name": "Roberto", "orcid": "0000-0003-3977-8760" }, { "family_name": "Vink", "given_name": "Jacco", "orcid": "0000-0002-4708-4219" }, { "family_name": "Weisskopf", "given_name": "Martin C.", "orcid": "0000-0002-5270-4240" }, { "family_name": "Wu", "given_name": "Kinwah", "orcid": "0000-0002-7568-8765" }, { "family_name": "Xie", "given_name": "Fei", "orcid": "0000-0002-0105-5826" }, { "family_name": "Zane", "given_name": "Silvia", "orcid": "0000-0001-5326-880X" } ], "abstract": "Most of the light from blazars, active galactic nuclei with jets of magnetized plasma that point nearly along the line of sight, is produced by high-energy particles, up to around 1\u2009TeV. Although the jets are known to be ultimately powered by a supermassive black hole, how the particles are accelerated to such high energies has been an unanswered question. The process must be related to the magnetic field, which can be probed by observations of the polarization of light from the jets. Measurements of the radio to optical polarization\u2014the only range available until now\u2014probe extended regions of the jet containing particles that left the acceleration site days to years earlier, and hence do not directly explore the acceleration mechanism, as could X-ray measurements. Here we report the detection of X-ray polarization from the blazar Markarian 501 (Mrk 501). We measure an X-ray linear polarization degree \u03a0X of around 10%, which is a factor of around 2 higher than the value at optical wavelengths, with a polarization angle parallel to the radio jet. This points to a shock front as the source of particle acceleration and also implies that the plasma becomes increasingly turbulent with distance from the shock.", "doi": "10.1038/s41586-022-05338-0", "pmcid": "PMC9684068", "issn": "0028-0836", "publisher": "Nature Publishing Group", "publication": "Nature", "publication_date": "2022-11-24", "series_number": "7937", "volume": "611", "issue": "7937", "pages": "677-681" }, { "id": "authors:npdzz-q5b30", "collection": "authors", "collection_id": "npdzz-q5b30", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230103-818063100.52", "type": "article", "title": "Observations of 4U 1626\u201367 with the Imaging X-Ray Polarimetry Explorer", "author": [ { "family_name": "Marshall", "given_name": "Herman L.", "orcid": "0000-0002-6492-1293", "clpid": "Marshall-Herman-L" }, { "family_name": "Ng", "given_name": "Mason", "orcid": "0000-0002-0940-6563" }, { "family_name": "Rogantini", "given_name": "Daniele", "orcid": "0000-0002-5359-9497" }, { "family_name": "Heyl", "given_name": "Jeremy", "orcid": "0000-0001-9739-367X" }, { "family_name": "Tsygankov", "given_name": "Sergey S.", "orcid": "0000-0002-9679-0793" }, { "family_name": "Poutanen", "given_name": "Juri", "orcid": "0000-0002-0983-0049" }, { "family_name": "Costa", "given_name": "Enrico", "orcid": "0000-0003-4925-8523" }, { "family_name": "Zane", "given_name": "Silvia", "orcid": "0000-0001-5326-880X" }, { "family_name": "Malacaria", "given_name": "Christian", "orcid": "0000-0002-0380-0041" }, { "family_name": "Agudo", "given_name": "Iv\u00e1n", "orcid": "0000-0002-3777-6182" }, { "family_name": "Antonelli", "given_name": "Lucio A.", "orcid": "0000-0002-5037-9034" }, { "family_name": "Bachetti", "given_name": "Matteo", "orcid": "0000-0002-4576-9337" }, { "family_name": "Baldini", "given_name": "Luca", "orcid": "0000-0002-9785-7726" }, { "family_name": "Baumgartner", "given_name": "Wayne H.", "orcid": "0000-0002-5106-0463" }, { "family_name": "Bellazzini", "given_name": "Ronaldo", "orcid": "0000-0002-2469-7063" }, { "family_name": "Bianchi", "given_name": "Stefano", "orcid": "0000-0002-4622-4240" }, { "family_name": "Bongiorno", "given_name": "Stephen D.", "orcid": "0000-0002-0901-2097" }, { "family_name": "Bonino", "given_name": "Raffaella", "orcid": "0000-0002-4264-1215" }, { "family_name": "Brez", "given_name": "Alessandro", "orcid": "0000-0002-9460-1821" }, { "family_name": "Bucciantini", "given_name": "Niccol\u00f2", "orcid": "0000-0002-8848-1392" }, { "family_name": "Capitanio", "given_name": "Fiamma", "orcid": "0000-0002-6384-3027" }, { "family_name": "Castellano", "given_name": "Simone", "orcid": "0000-0003-1111-4292" }, { "family_name": "Cavazzuti", "given_name": "Elisabetta", "orcid": "0000-0001-7150-9638" }, { "family_name": "Ciprini", "given_name": "Stefano", "orcid": "0000-0002-0712-2479" }, { "family_name": "De Rosa", "given_name": "Alessandra", "orcid": "0000-0001-5668-6863" }, { "family_name": "Monte", "given_name": "Ettore Del", "orcid": "0000-0002-3013-6334" }, { "family_name": "Gesu", "given_name": "Laura Di", "orcid": "0000-0002-5614-5028" }, { "family_name": "Lalla", "given_name": "Niccol\u00f2 Di", "orcid": "0000-0002-7574-1298" }, { "family_name": "Marco", "given_name": "Alessandro Di", "orcid": "0000-0003-0331-3259" }, { "family_name": "Donnarumma", "given_name": "Immacolata", "orcid": "0000-0002-4700-4549" }, { "family_name": "Doroshenko", "given_name": "Victor", "orcid": "0000-0001-8162-1105" }, { "family_name": "Dov\u010diak", "given_name": "Michal", "orcid": "0000-0003-0079-1239" }, { "family_name": "Ehlert", "given_name": "Steven R.", "orcid": "0000-0003-4420-2838" }, { "family_name": "Enoto", "given_name": "Teruaki", "orcid": "0000-0003-1244-3100" }, { "family_name": "Evangelista", "given_name": "Yuri", "orcid": "0000-0001-6096-6710" }, { "family_name": "Fabiani", "given_name": "Sergio", "orcid": "0000-0003-1533-0283" }, { "family_name": "Ferrazzoli", "given_name": "Riccardo", "orcid": "0000-0003-1074-8605" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Gunji", "given_name": "Shuichi", "orcid": "0000-0002-5881-2445" }, { "family_name": "Hayashida", "given_name": "Kiyoshi", "orcid": "0000-0002-0110-6136" }, { "family_name": "Iwakiri", "given_name": "Wataru", "orcid": "0000-0002-0207-9010" }, { "family_name": "Jorstad", "given_name": "Svetlana G.", "orcid": "0000-0001-9522-5453" }, { "family_name": "Karas", "given_name": "Vladimir", "orcid": "0000-0002-5760-0459" }, { "family_name": "Kitaguchi", "given_name": "Takao" }, { "family_name": "Krawczynski", "given_name": "Henric", "orcid": "0000-0002-1084-6507" }, { "family_name": "La Monaca", "given_name": "Fabio", "orcid": "0000-0001-8916-4156" }, { "family_name": "Latronico", "given_name": "Luca", "orcid": "0000-0002-0984-1856" }, { "family_name": "Liodakis", "given_name": "Ioannis", "orcid": "0000-0001-9200-4006" }, { "family_name": "Maldera", "given_name": "Simone", "orcid": "0000-0002-0698-4421" }, { "family_name": "Manfreda", "given_name": "Alberto", "orcid": "0000-0002-0998-4953" }, { "family_name": "Marin", "given_name": "Fr\u00e9d\u00e9ric", "orcid": "0000-0003-4952-0835" }, { "family_name": "Marinucci", "given_name": "Andrea", "orcid": "0000-0002-2055-4946" }, { "family_name": "Marscher", "given_name": "Alan P.", "orcid": "0000-0001-7396-3332" }, { "family_name": "Matt", "given_name": "Giorgio", "orcid": "0000-0002-2152-0916" }, { "family_name": "Mitsuishi", "given_name": "Ikuyuki" }, { "family_name": "Mizuno", "given_name": "Tsunefumi", "orcid": "0000-0001-7263-0296" }, { "family_name": "Muleri", "given_name": "Fabio", "orcid": "0000-0003-3331-3794" }, { "family_name": "Ng", "given_name": "C.-Y.", "orcid": "0000-0002-5847-2612" }, { "family_name": "O'Dell", "given_name": "Stephen L.", "orcid": "0000-0002-1868-8056" }, { "family_name": "Omodei", "given_name": "Nicola", "orcid": "0000-0002-5448-7577" }, { "family_name": "Oppedisano", "given_name": "Chiara", "orcid": "0000-0001-6194-4601" }, { "family_name": "Papitto", "given_name": "Alessandro", "orcid": "0000-0001-6289-7413" }, { "family_name": "Pavlov", "given_name": "George G.", "orcid": "0000-0002-7481-5259" }, { "family_name": "Peirson", "given_name": "Abel L.", "orcid": "0000-0001-6292-1911" }, { "family_name": "Perri", "given_name": "Matteo", "orcid": "0000-0003-3613-4409" }, { "family_name": "Pesce-Rollins", "given_name": "Melissa", "orcid": "0000-0003-1790-8018" }, { "family_name": "Petrucci", "given_name": "Pierre-Olivier", "orcid": "0000-0001-6061-3480" }, { "family_name": "Pilia", "given_name": "Maura", "orcid": "0000-0001-7397-8091" }, { "family_name": "Possenti", "given_name": "Andrea", "orcid": "0000-0001-5902-3731" }, { "family_name": "Puccetti", "given_name": "Simonetta", "orcid": "0000-0002-2734-7835" }, { "family_name": "Ramsey", "given_name": "Brian D.", "orcid": "0000-0003-1548-1524" }, { "family_name": "Rankin", "given_name": "John", "orcid": "0000-0002-9774-0560" }, { "family_name": "Ratheesh", "given_name": "Ajay", "orcid": "0000-0003-0411-4243" }, { "family_name": "Romani", "given_name": "Roger W.", "orcid": "0000-0001-6711-3286" }, { "family_name": "Sgr\u00f2", "given_name": "Carmelo", "orcid": "0000-0001-5676-6214" }, { "family_name": "Slane", "given_name": "Patrick", "orcid": "0000-0002-6986-6756" }, { "family_name": "Spandre", "given_name": "Gloria", "orcid": "0000-0003-0802-3453" }, { "family_name": "Tamagawa", "given_name": "Toru", "orcid": "0000-0002-8801-6263" }, { "family_name": "Tavecchio", "given_name": "Fabrizio", "orcid": "0000-0003-0256-0995" }, { "family_name": "Taverna", "given_name": "Roberto", "orcid": "0000-0002-1768-618X" }, { "family_name": "Tawara", "given_name": "Yuzuru" }, { "family_name": "Tennant", "given_name": "Allyn F.", "orcid": "0000-0002-9443-6774" }, { "family_name": "Thomas", "given_name": "Nicholas E.", "orcid": "0000-0003-0411-4606" }, { "family_name": "Tombesi", "given_name": "Francesco", "orcid": "0000-0002-6562-8654" }, { "family_name": "Trois", "given_name": "Alessio", "orcid": "0000-0002-3180-6002" }, { "family_name": "Turolla", "given_name": "Roberto", "orcid": "0000-0003-3977-8760" }, { "family_name": "Vink", "given_name": "Jacco", "orcid": "0000-0002-4708-4219" }, { "family_name": "Weisskopf", "given_name": "Martin C.", "orcid": "0000-0002-5270-4240" }, { "family_name": "Wu", "given_name": "Kinwah", "orcid": "0000-0002-7568-8765" }, { "family_name": "Xie", "given_name": "Fei", "orcid": "0000-0002-0105-5826" }, { "family_name": "Schulz", "given_name": "Norbert S.", "orcid": "0000-0002-0842-7792" }, { "family_name": "Chakrabarty", "given_name": "Deepto", "orcid": "0000-0001-8804-8946" } ], "abstract": "We present measurements of the polarization of X-rays in the 2\u20138 keV band from the pulsar in the ultracompact low-mass X-ray binary 4U 1626\u201367 using data from the Imaging X-Ray Polarimetry Explorer (IXPE). The 7.66 s pulsations were clearly detected throughout the IXPE observations as well as in the NICER soft X-ray observations, which we used as the basis for our timing analysis and to constrain the spectral shape over the 0.4\u201310 keV energy band. Chandra HETGS high-resolution X-ray spectra were also obtained near the times of the IXPE observations for firm spectral modeling. We found an upper limit on the pulse-averaged linear polarization of <4% (at 95% confidence). Similarly, there was no significant detection of polarized flux in pulse phase intervals when subdividing the bandpass by energy. However, spectropolarimetric modeling over the full bandpass in pulse phase intervals provided a marginal detection of polarization of the power-law spectral component at the 4.8% \u00b1 2.3% level (90% confidence). We discuss the implications concerning the accretion geometry onto the pulsar, favoring two-component models of the pulsed emission.", "doi": "10.3847/1538-4357/ac98c2", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2022-11-20", "series_number": "1", "volume": "940", "issue": "1", "pages": "Art. No. 70" }, { "id": "authors:q5fs0-fwh71", "collection": "authors", "collection_id": "q5fs0-fwh71", "cite_using_url": "https://authors.library.caltech.edu/records/q5fs0-fwh71", "type": "article", "title": "Polarized x-rays from a magnetar", "author": [ { "family_name": "Taverna", "given_name": "Roberto", "orcid": "0000-0002-1768-618X" }, { "family_name": "Turolla", "given_name": "Roberto" }, { "family_name": "Muleri", "given_name": "Fabio", "orcid": "0000-0003-3331-3794" }, { "family_name": "Heyl", "given_name": "Jeremy", "orcid": "0000-0001-9739-367X" }, { "family_name": "Zane", "given_name": "Silvia", "orcid": "0000-0001-5326-880X" }, { "family_name": "Baldini", "given_name": "Luca", "orcid": "0000-0002-9785-7726" }, { "family_name": "Gonz\u00e1lez-Caniulef", "given_name": "Denis", "orcid": "0000-0001-5848-0180" }, { "family_name": "Bachetti", "given_name": "Matteo", "orcid": "0000-0002-4576-9337" }, { "family_name": "Rankin", "given_name": "John", "orcid": "0000-0002-9774-0560" }, { "family_name": "Caiazzo", "given_name": "Ilaria", "orcid": "0000-0002-4770-5388", "clpid": "Calazzo-Ilaria" }, { "family_name": "Di Lalla", "given_name": "Niccol\u00f2", "orcid": "0000-0002-7574-1298" }, { "family_name": "Doroshenko", "given_name": "Victor", "orcid": "0000-0001-8162-1105" }, { "family_name": "Errando", "given_name": "Manel", "orcid": "0000-0002-1853-863X" }, { "family_name": "Gau", "given_name": "Ephraim", "orcid": "0000-0002-5250-2710" }, { "family_name": "K\u0131rm\u0131z\u0131bayrak", "given_name": "Demet", "orcid": "0000-0003-2675-740X" }, { "family_name": "Krawczynski", "given_name": "Henric", "orcid": "0000-0002-1084-6507" }, { "family_name": "Negro", "given_name": "Michela", "orcid": "0000-0002-6548-5622" }, { "family_name": "Ng", "given_name": "Mason", "orcid": "0000-0002-0940-6563" }, { "family_name": "Omodei", "given_name": "Nicola", "orcid": "0000-0002-5448-7577" }, { "family_name": "Possenti", "given_name": "Andrea", "orcid": "0000-0001-5902-3731" }, { "family_name": "Tamagawa", "given_name": "Toru", "orcid": "0000-0002-8801-6263" }, { "family_name": "Uchiyama", "given_name": "Keisuke", "orcid": "0000-0002-7752-9389" }, { "family_name": "Weisskopf", "given_name": "Martin C.", "orcid": "0000-0002-5270-4240" }, { "family_name": "Agudo", "given_name": "Ivan", "orcid": "0000-0002-3777-6182" }, { "family_name": "Antonelli", "given_name": "Lucio A." }, { "family_name": "Baumgartner", "given_name": "Wayne H." }, { "family_name": "Bellazzini", "given_name": "Ronaldo" }, { "family_name": "Bianchi", "given_name": "Stefano", "orcid": "0000-0002-4622-4240" }, { "family_name": "Bongiorno", "given_name": "Stephen D.", "orcid": "0000-0002-0901-2097" }, { "family_name": "Bonino", "given_name": "Raffaella", "orcid": "0000-0002-4264-1215" }, { "family_name": "Brez", "given_name": "Alessandro" }, { "family_name": "Bucciantini", "given_name": "Niccol\u00f2" }, { "family_name": "Capitanio", "given_name": "Fiamma", "orcid": "0000-0002-6384-3027" }, { "family_name": "Castellano", "given_name": "Simone", "orcid": "0000-0003-1111-4292" }, { "family_name": "Cavazzuti", "given_name": "Elisabetta", "orcid": "0000-0001-7150-9638" }, { "family_name": "Ciprini", "given_name": "Stefano", "orcid": "0000-0002-0712-2479" }, { "family_name": "Costa", "given_name": "Enrico" }, { "family_name": "De Rosa", "given_name": "Alessandra" }, { "family_name": "Del Monte", "given_name": "Ettore", "orcid": "0000-0002-3013-6334" }, { "family_name": "Di Gesu", "given_name": "Laura", "orcid": "0000-0002-5614-5028" }, { "family_name": "Di Marco", "given_name": "Alessandro", "orcid": "0000-0003-0331-3259" }, { "family_name": "Donnarumma", "given_name": "Immacolata" }, { "family_name": "Dov\u010diak", "given_name": "Michal", "orcid": "0000-0003-0079-1239" }, { "family_name": "Ehlert", "given_name": "Steven R.", "orcid": "0000-0003-4420-2838" }, { "family_name": "Enoto", "given_name": "Teruaki", "orcid": "0000-0003-1244-3100" }, { "family_name": "Evangelista", "given_name": "Yuri", "orcid": "0000-0001-6096-6710" }, { "family_name": "Fabiani", "given_name": "Sergio" }, { "family_name": "Ferrazzoli", "given_name": "Riccardo" }, { "family_name": "Garcia", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Gunji", "given_name": "Shuichi", "orcid": "0000-0002-5881-2445" }, { "family_name": "Hayashida", "given_name": "Kiyoshi" }, { "family_name": "Iwakiri", "given_name": "Wataru" }, { "family_name": "Jorstad", "given_name": "Svetlana G.", "orcid": "0000-0001-6158-1708" }, { "family_name": "Karas", "given_name": "Vladimir" }, { "family_name": "Kitaguchi", "given_name": "Takao" }, { "family_name": "Kolodziejczak", "given_name": "Jeffery J.", "orcid": "0000-0002-0110-6136" }, { "family_name": "La Monaca", "given_name": "Fabio", "orcid": "0000-0001-8916-4156" }, { "family_name": "Latronico", "given_name": "Luca", "orcid": "0000-0002-0984-1856" }, { "family_name": "Liodakis", "given_name": "Ioannis", "orcid": "0000-0001-9200-4006" }, { "family_name": "Maldera", "given_name": "Simone", "orcid": "0000-0002-0698-4421" }, { "family_name": "Manfreda", "given_name": "Alberto", "orcid": "0000-0002-0998-4953" }, { "family_name": "Marin", "given_name": "Fr\u00e9d\u00e9ric", "orcid": "0000-0003-2049-2690" }, { "family_name": "Marinucci", "given_name": "Andrea", "orcid": "0000-0002-2055-4946" }, { "family_name": "Marscher", "given_name": "Alan P.", "orcid": "0000-0001-7396-3332" }, { "family_name": "Marshall", "given_name": "Herman L." }, { "family_name": "Matt", "given_name": "Giorgio", "orcid": "0000-0002-2152-0916" }, { "family_name": "Mitsuishi", "given_name": "Ikuyuki" }, { "family_name": "Mizuno", "given_name": "Tsunefumi", "orcid": "0000-0001-7263-0296" }, { "family_name": "Ng", "given_name": "Stephen C.-Y.", "orcid": "0000-0002-5847-2612" }, { "family_name": "O'Dell", "given_name": "Stephen L.", "orcid": "0000-0002-1868-8056" }, { "family_name": "Oppedisano", "given_name": "Chiara", "orcid": "0000-0001-6194-4601" }, { "family_name": "Papitto", "given_name": "Alessandro", "orcid": "0000-0001-6289-7413" }, { "family_name": "Pavlov", "given_name": "George G." }, { "family_name": "Peirson", "given_name": "Abel L.", "orcid": "0000-0001-6292-1911" }, { "family_name": "Perri", "given_name": "Matteo", "orcid": "0000-0003-3613-4409" }, { "family_name": "Pesce-Rollins", "given_name": "Melissa", "orcid": "0000-0003-1790-8018" }, { "family_name": "Pilia", "given_name": "Maura" }, { "family_name": "Poutanen", "given_name": "Juri", "orcid": "0000-0002-0983-0049" }, { "family_name": "Puccetti", "given_name": "Simonetta" }, { "family_name": "Ramsey", "given_name": "Brian D." }, { "family_name": "Ratheesh", "given_name": "Ajay", "orcid": "0000-0003-0411-4243" }, { "family_name": "Romani", "given_name": "Roger W." }, { "family_name": "Sgr\u00f2", "given_name": "Carmelo", "orcid": "0000-0001-5676-6214" }, { "family_name": "Slane", "given_name": "Patrick" }, { "family_name": "Soffitta", "given_name": "Paolo", "orcid": "0000-0002-7781-4104" }, { "family_name": "Spandre", "given_name": "Gloria", "orcid": "0000-0003-0802-3453" }, { "family_name": "Tavecchio", "given_name": "Fabrizio", "orcid": "0000-0003-0256-0995" }, { "family_name": "Tawara", "given_name": "Yuzuru" }, { "family_name": "Tennant", "given_name": "Allyn F.", "orcid": "0000-0002-9443-6774" }, { "family_name": "Thomas", "given_name": "Nicholas E." }, { "family_name": "Tombesi", "given_name": "Francesco", "orcid": "0000-0002-6562-8654" }, { "family_name": "Trois", "given_name": "Alessio" }, { "family_name": "Tsygankov", "given_name": "Sergey S.", "orcid": "0000-0002-9679-0793" }, { "family_name": "Vink", "given_name": "Jacco" }, { "family_name": "Wu", "given_name": "Kinwah" }, { "family_name": "Xie", "given_name": "Fei", "orcid": "0000-0002-0105-5826" } ], "abstract": "Magnetars are neutron stars with ultrastrong magnetic fields, which can be observed in x-rays. Polarization measurements could provide information on their magnetic fields and surface properties. We observed polarized x-rays from the magnetar 4U 0142+61 using the Imaging X-ray Polarimetry Explorer and found a linear polarization degree of 13.5 \u00b1 0.8% averaged over the 2\u2013 to 8\u2013kilo\u2013electron volt band. The polarization changes with energy: The degree is 15.0 \u00b1 1.0% at 2 to 4 kilo\u2013electron volts, drops below the instrumental sensitivity ~4 to 5 kilo\u2013electron volts, and rises to 35.2 \u00b1 7.1% at 5.5 to 8 kilo\u2013electron volts. The polarization angle also changes by 90\u00b0 at ~4 to 5 kilo\u2013electron volts. These results are consistent with a model in which thermal radiation from the magnetar surface is reprocessed by scattering off charged particles in the magnetosphere.", "doi": "10.1126/science.add0080", "issn": "0036-8075", "publisher": "American Association for the Advancement of Science", "publication": "Science", "publication_date": "2022-11-11", "series_number": "6620", "volume": "378", "issue": "6620", "pages": "646-650" }, { "id": "authors:61e8x-ptd66", "collection": "authors", "collection_id": "61e8x-ptd66", "cite_using_url": "https://authors.library.caltech.edu/records/61e8x-ptd66", "type": "article", "title": "Polarized x-rays constrain the disk-jet geometry in the black hole x-ray binary Cygnus X-1", "author": [ { "family_name": "Krawczynski", "given_name": "Henric", "orcid": "0000-0002-1084-6507" }, { "family_name": "Muleri", "given_name": "Fabio", "orcid": "0000-0003-3331-3794" }, { "family_name": "Dov\u010diak", "given_name": "Michal", "orcid": "0000-0003-0079-1239" }, { "family_name": "Veledina", "given_name": "Alexandra", "orcid": "0000-0002-5767-7253" }, { "family_name": "Rodriguez Cavero", "given_name": "Nicole", "orcid": "0000-0001-5256-0278" }, { "family_name": "Svoboda", "given_name": "Jiri", "orcid": "0000-0003-2931-0742" }, { "family_name": "Ingram", "given_name": "Adam", "orcid": "0000-0002-5311-9078" }, { "family_name": "Matt", "given_name": "Giorgio", "orcid": "0000-0002-2152-0916" }, { "family_name": "Garcia", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Loktev", "given_name": "Vladislav", "orcid": "0000-0001-6894-871X" }, { "family_name": "Negro", "given_name": "Michela", "orcid": "0000-0002-6548-5622" }, { "family_name": "Poutanen", "given_name": "Juri", "orcid": "0000-0002-0983-0049" }, { "family_name": "Kitaguchi", "given_name": "Takao" }, { "family_name": "Podgorn\u00fd", "given_name": "Jakub", "orcid": "0000-0001-5418-291X" }, { "family_name": "Rankin", "given_name": "John", "orcid": "0000-0002-9774-0560" }, { "family_name": "Zhang", "given_name": "Wenda", "orcid": "0000-0003-1702-4917" }, { "family_name": "Berdyugin", "given_name": "Andrei", "orcid": "0000-0002-9353-5164" }, { "family_name": "Berdyugina", "given_name": "Svetlana V.", "orcid": "0000-0002-2238-7416" }, { "family_name": "Bianchi", "given_name": "Stefano", "orcid": "0000-0002-4622-4240" }, { "family_name": "Blinov", "given_name": "Dmitry", "orcid": "0000-0003-0611-5784" }, { "family_name": "Capitanio", "given_name": "Fiamma", "orcid": "0000-0002-6384-3027" }, { "family_name": "Di Lalla", "given_name": "Niccol\u00f2", "orcid": "0000-0002-7574-1298" }, { "family_name": "Draghis", "given_name": "Paul", "orcid": "0000-0002-2218-2306" }, { "family_name": "Fabiani", "given_name": "Sergio", "orcid": "0000-0003-1533-0283" }, { "family_name": "Kagitani", "given_name": "Masato" }, { "family_name": "Kravtsov", "given_name": "Vadim", "orcid": "0000-0002-7502-3173" }, { "family_name": "Kiehlmann", "given_name": "Sebastian", "orcid": "0000-0001-6314-9177" }, { "family_name": "Latronico", "given_name": "Luca", "orcid": "0000-0002-0984-1856" }, { "family_name": "Lutovinov", "given_name": "Alexander A.", "orcid": "0000-0002-6255-9972" }, { "family_name": "Mandarakas", "given_name": "Nikos", "orcid": "0000-0002-2567-2132" }, { "family_name": "Marin", "given_name": "Fr\u00e9d\u00e9ric", "orcid": "0000-0003-2049-2690" }, { "family_name": "Marinucci", "given_name": "Andrea", "orcid": "0000-0002-2055-4946" }, { "family_name": "Miller", "given_name": "Jon M.", "orcid": "0000-0003-2869-7682" }, { "family_name": "Mizuno", "given_name": "Tsunefumi", "orcid": "0000-0001-7263-0296" }, { "family_name": "Molkov", "given_name": "Sergey V.", "orcid": "0000-0002-5983-5788" }, { "family_name": "Omodei", "given_name": "Nicola", "orcid": "0000-0002-5448-7577" }, { "family_name": "Petrucci", "given_name": "Pierre-Olivier", "orcid": "0000-0001-6061-3480" }, { "family_name": "Ratheesh", "given_name": "Ajay", "orcid": "0000-0003-0411-4243" }, { "family_name": "Sakanoi", "given_name": "Takeshi", "orcid": "0000-0002-7146-9020" }, { "family_name": "Semena", "given_name": "Andrei N." }, { "family_name": "Skalidis", "given_name": "Raphael", "orcid": "0000-0003-2337-0277" }, { "family_name": "Soffitta", "given_name": "Paolo", "orcid": "0000-0002-7781-4104" }, { "family_name": "Tennant", "given_name": "Allyn F.", "orcid": "0000-0002-9443-6774" }, { "family_name": "Thalhammer", "given_name": "Phillipp" }, { "family_name": "Tombesi", "given_name": "Francesco", "orcid": "0000-0002-6562-8654" }, { "family_name": "Weisskopf", "given_name": "Martin C.", "orcid": "0000-0002-5270-4240" }, { "family_name": "Wilms", "given_name": "Joern", "orcid": "0000-0003-2065-5410" }, { "family_name": "Zhang", "given_name": "Sixuan" }, { "family_name": "Agudo", "given_name": "Iv\u00e1n", "orcid": "0000-0002-3777-6182" }, { "family_name": "Antonelli", "given_name": "Lucio A.", "orcid": "0000-0002-5037-9034" }, { "family_name": "Bachetti", "given_name": "Matteo", "orcid": "0000-0002-4576-9337" }, { "family_name": "Baldini", "given_name": "Luca", "orcid": "0000-0002-9785-7726" }, { "family_name": "Baumgartner", "given_name": "Wayne H." }, { "family_name": "Bellazzini", "given_name": "Ronaldo" }, { "family_name": "Bongiorno", "given_name": "Stephen D.", "orcid": "0000-0002-0901-2097" }, { "family_name": "Bonino", "given_name": "Raffaella", "orcid": "0000-0002-4264-1215" }, { "family_name": "Brez", "given_name": "Alessandro" }, { "family_name": "Bucciantini", "given_name": "Niccol\u00f2", "orcid": "0000-0002-8848-1392" }, { "family_name": "Castellano", "given_name": "Simone", "orcid": "0000-0003-1111-4292" }, { "family_name": "Cavazzuti", "given_name": "Elisabetta", "orcid": "0000-0001-7150-9638" }, { "family_name": "Ciprini", "given_name": "Stefano", "orcid": "0000-0002-0712-2479" }, { "family_name": "Costa", "given_name": "Enrico" }, { "family_name": "De Rosa", "given_name": "Alessandra", "orcid": "0000-0001-5668-6863" }, { "family_name": "Del Monte", "given_name": "Ettore", "orcid": "0000-0002-3013-6334" }, { "family_name": "Di Gesu", "given_name": "Laura", "orcid": "0000-0002-5614-5028" }, { "family_name": "Di Marco", "given_name": "Alessandro", "orcid": "0000-0003-0331-3259" }, { "family_name": "Donnarumma", "given_name": "Immacolata", "orcid": "0000-0002-4700-4549" }, { "family_name": "Doroshenko", "given_name": "Victor", "orcid": "0000-0001-8162-1105" }, { "family_name": "Ehlert", "given_name": "Steven R.", "orcid": "0000-0003-4420-2838" }, { "family_name": "Enoto", "given_name": "Teruaki", "orcid": "0000-0003-1244-3100" }, { "family_name": "Evangelista", "given_name": "Yuri", "orcid": "0000-0001-6096-6710" }, { "family_name": "Ferrazzoli", "given_name": "Riccardo", "orcid": "0000-0003-1074-8605" }, { "family_name": "Gunji", "given_name": "Shuichi", "orcid": "0000-0002-5881-2445" }, { "family_name": "Hayashida", "given_name": "Kiyoshi" }, { "family_name": "Heyl", "given_name": "Jeremy", "orcid": "0000-0001-9739-367X" }, { "family_name": "Iwakiri", "given_name": "Wataru", "orcid": "0000-0002-0207-9010" }, { "family_name": "Jorstad", "given_name": "Svetlana G.", "orcid": "0000-0001-6158-1708" }, { "family_name": "Karas", "given_name": "Vladimir", "orcid": "0000-0002-5760-0459" }, { "family_name": "Kolodziejczak", "given_name": "Jeffery J.", "orcid": "0000-0002-0110-6136" }, { "family_name": "La Monaca", "given_name": "Fabio", "orcid": "0000-0001-8916-4156" }, { "family_name": "Liodakis", "given_name": "Ioannis", "orcid": "0000-0001-9200-4006" }, { "family_name": "Maldera", "given_name": "Simone", "orcid": "0000-0002-0698-4421" }, { "family_name": "Manfreda", "given_name": "Alberto", "orcid": "0000-0002-0998-4953" }, { "family_name": "Marscher", "given_name": "Alan P.", "orcid": "0000-0001-7396-3332" }, { "family_name": "Marshall", "given_name": "Herman L.", "orcid": "0000-0002-6492-1293" }, { "family_name": "Mitsuishi", "given_name": "Ikuyuki", "orcid": "0000-0002-9901-233X" }, { "family_name": "Ng", "given_name": "Chi-Yung", "orcid": "0000-0002-5847-2612" }, { "family_name": "O'Dell", "given_name": "Stephen L.", "orcid": "0000-0002-1868-8056" }, { "family_name": "Oppedisano", "given_name": "Chiara", "orcid": "0000-0001-6194-4601" }, { "family_name": "Papitto", "given_name": "Alessandro", "orcid": "0000-0001-6289-7413" }, { "family_name": "Pavlov", "given_name": "George G." }, { "family_name": "Peirson", "given_name": "Abel L.", "orcid": "0000-0001-6292-1911" }, { "family_name": "Perri", "given_name": "Matteo", "orcid": "0000-0003-3613-4409" }, { "family_name": "Pesce-Rollins", "given_name": "Melissa", "orcid": "0000-0003-1790-8018" }, { "family_name": "Pilia", "given_name": "Maura", "orcid": "0000-0001-7397-8091" }, { "family_name": "Possenti", "given_name": "Andrea", "orcid": "0000-0001-5902-3731" }, { "family_name": "Puccetti", "given_name": "Simonetta" }, { "family_name": "Ramsey", "given_name": "Brian D.", "orcid": "0000-0003-1548-1524" }, { "family_name": "Romani", "given_name": "Roger W." }, { "family_name": "Sgr\u00f2", "given_name": "Carmelo", "orcid": "0000-0001-5676-6214" }, { "family_name": "Slane", "given_name": "Patrick", "orcid": "0000-0002-6986-6756" }, { "family_name": "Spandre", "given_name": "Gloria", "orcid": "0000-0003-0802-3453" }, { "family_name": "Tamagawa", "given_name": "Toru", "orcid": "0000-0002-8801-6263" }, { "family_name": "Tavecchio", "given_name": "Fabrizio", "orcid": "0000-0003-0256-0995" }, { "family_name": "Taverna", "given_name": "Roberto", "orcid": "0000-0002-1768-618X" }, { "family_name": "Tawara", "given_name": "Yuzuru" }, { "family_name": "Thomas", "given_name": "Nicholas E." }, { "family_name": "Trois", "given_name": "Alessio", "orcid": "0000-0002-3180-6002" }, { "family_name": "Tsygankov", "given_name": "Sergey", "orcid": "0000-0002-9679-0793" }, { "family_name": "Turolla", "given_name": "Roberto", "orcid": "0000-0003-3977-8760" }, { "family_name": "Vink", "given_name": "Jacco", "orcid": "0000-0002-4708-4219" }, { "family_name": "Wu", "given_name": "Kinwah", "orcid": "0000-0002-7568-8765" }, { "family_name": "Xie", "given_name": "Fei", "orcid": "0000-0002-0105-5826" }, { "family_name": "Zane", "given_name": "Silvia", "orcid": "0000-0001-5326-880X" } ], "abstract": "

A black hole x-ray binary (XRB) system forms when gas is stripped from a normal star and accretes onto a black hole, which heats the gas sufficiently to emit x-rays. We report a polarimetric observation of the XRB Cygnus X-1 using the Imaging X-ray Polarimetry Explorer. The electric field position angle aligns with the outflowing jet, indicating that the jet is launched from the inner x-ray–emitting region. The polarization degree is 4.01 ± 0.20% at 2 to 8 kiloelectronvolts, implying that the accretion disk is viewed closer to edge-on than the binary orbit. These observations reveal that hot x-ray–emitting plasma is spatially extended in a plane perpendicular to, not parallel to, the jet axis.

", "doi": "10.1126/science.add5399", "issn": "0036-8075", "publisher": "American Association for the Advancement of Science", "publication": "Science", "publication_date": "2022-11-11", "series_number": "6620", "volume": "378", "issue": "6620", "pages": "650-654" }, { "id": "authors:8fvrg-vfn93", "collection": "authors", "collection_id": "8fvrg-vfn93", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20221128-494241100.41", "type": "article", "title": "X-Ray Reverberation Mapping of Ark 564 Using Gaussian Process Regression", "author": [ { "family_name": "Lewin", "given_name": "Collin", "orcid": "0000-0002-8671-1190", "clpid": "Lewin-Collin" }, { "family_name": "Kara", "given_name": "Erin", "orcid": "0000-0003-0172-0854", "clpid": "Kara-Erin" }, { "family_name": "Wilkins", "given_name": "Dan", "orcid": "0000-0002-4794-5998", "clpid": "Wilkins-Dan" }, { "family_name": "Mastroserio", "given_name": "Guglielmo", "orcid": "0000-0003-4216-7936", "clpid": "Mastroserio-Guglielmo" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Zhang", "given_name": "Rachel C.", "orcid": "0000-0002-2905-9239", "clpid": "Zhang-Rachel-C" }, { "family_name": "Alston", "given_name": "William N.", "orcid": "0000-0003-2658-6559", "clpid": "Alston-William-N" }, { "family_name": "Connors", "given_name": "Riley", "orcid": "0000-0002-8908-759X", "clpid": "Connors-Riley-M-T" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-Thomas" }, { "family_name": "Fabian", "given_name": "Andrew", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-Andrew-C" }, { "family_name": "Ingram", "given_name": "Adam", "orcid": "0000-0002-5311-9078", "clpid": "Ingram-Adam" }, { "family_name": "Jiang", "given_name": "Jiachen", "orcid": "0000-0002-9639-4352", "clpid": "Jiang-Jiachen" }, { "family_name": "Lohfink", "given_name": "Anne M.", "clpid": "Lohfink-Anne-M" }, { "family_name": "Lucchini", "given_name": "Matteo", "orcid": "0000-0002-2235-3347", "clpid": "Lucchini-Matteo" }, { "family_name": "Reynolds", "given_name": "Christopher S.", "orcid": "0000-0002-1510-4860", "clpid": "Reynolds-Christopher-S" }, { "family_name": "Tombesi", "given_name": "Francesco", "orcid": "0000-0002-6562-8654", "clpid": "Tombesi-Francesco" }, { "family_name": "van der Klis", "given_name": "Michiel", "orcid": "0000-0003-0070-9872", "clpid": "van-der-Klis-Michiel" }, { "family_name": "Wang", "given_name": "Jingyi", "orcid": "0000-0002-1742-2125", "clpid": "Wang-Jingyi" } ], "abstract": "Ark 564 is an extreme high-Eddington narrow-line Seyfert 1 galaxy, known for being one of the brightest, most rapidly variable soft X-ray active galactic nuclei (AGN), and for having one of the lowest temperature coronae. Here, we present a 410 ks NuSTAR observation and two 115 ks XMM-Newton observations of this unique source, which reveal a very strong, relativistically broadened iron line. We compute the Fourier-resolved time lags by first using Gaussian processes to interpolate the NuSTAR gaps, implementing the first employment of multitask learning for application in AGN timing. By simultaneously fitting the time lags and the flux spectra with the relativistic reverberation model reltrans, we constrain the mass at 2.3_(-1.3)^(+2.6) x 10^(6)M_(\u2299), although additional components are required to describe the prominent soft excess in this source. These results motivate future combinations of machine learning, Fourier-resolved timing, and the development of reverberation models.", "doi": "10.3847/1538-4357/ac978f", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2022-11-10", "series_number": "2", "volume": "939", "issue": "2", "pages": "Art. No. 109" }, { "id": "authors:stc0z-6k888", "collection": "authors", "collection_id": "stc0z-6k888", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20221101-827781300.7", "type": "article", "title": "Polarization constraints on the X-ray corona in Seyfert Galaxies: MCG-05-23-16", "author": [ { "family_name": "Marinucci", "given_name": "A.", "orcid": "0000-0002-2055-4946", "clpid": "Marinucci-Andrea" }, { "family_name": "Muleri", "given_name": "F." }, { "family_name": "Dovciak", "given_name": "M." }, { "family_name": "Bianchi", "given_name": "S.", "orcid": "0000-0002-4622-4240" }, { "family_name": "Marin", "given_name": "F.", "orcid": "0000-0003-4952-0835" }, { "family_name": "Matt", "given_name": "G.", "orcid": "0000-0002-2152-0916" }, { "family_name": "Ursini", "given_name": "F.", "orcid": "0000-0001-9442-7897" }, { "family_name": "Middei", "given_name": "R.", "orcid": "0000-0001-9815-9092" }, { "family_name": "Marshall", "given_name": "H. L." }, { "family_name": "Baldini", "given_name": "L." }, { "family_name": "Barnouin", "given_name": "T." }, { "family_name": "Cavero Rodriguez", "given_name": "N." }, { "family_name": "De\u00a0Rosa", "given_name": "A.", "orcid": "0000-0001-5668-6863" }, { "family_name": "Di\u00a0Gesu", "given_name": "L." }, { "family_name": "Harper", "given_name": "D." }, { "family_name": "Ingram", "given_name": "A.", "orcid": "0000-0002-5311-9078" }, { "family_name": "Karas", "given_name": "V." }, { "family_name": "Krawczynski", "given_name": "H." }, { "family_name": "Madejski", "given_name": "G." }, { "family_name": "Panagiotou", "given_name": "C." }, { "family_name": "Petrucci", "given_name": "P. O." }, { "family_name": "Podgorny", "given_name": "J." }, { "family_name": "Puccetti", "given_name": "S.", "orcid": "0000-0002-2734-7835" }, { "family_name": "Tombesi", "given_name": "F.", "orcid": "0000-0002-6562-8654" }, { "family_name": "Veledina", "given_name": "A.", "orcid": "0000-0002-5767-7253" }, { "family_name": "Zhang", "given_name": "W." }, { "family_name": "Agudo", "given_name": "I.", "orcid": "0000-0002-3777-6182" }, { "family_name": "Antonelli", "given_name": "L. A.", "orcid": "0000-0002-5037-9034" }, { "family_name": "Bachetti", "given_name": "M.", "orcid": "0000-0002-4576-9337" }, { "family_name": "Baumgartner", "given_name": "W. H." }, { "family_name": "Bellazzini", "given_name": "R." }, { "family_name": "Bongiorno", "given_name": "S. D." }, { "family_name": "Bonino", "given_name": "R.", "orcid": "0000-0002-4264-1215" }, { "family_name": "Brez", "given_name": "A." }, { "family_name": "Bucciantini", "given_name": "N." }, { "family_name": "Capitanio", "given_name": "F." }, { "family_name": "Castellano", "given_name": "S." }, { "family_name": "Cavazzuti", "given_name": "E." }, { "family_name": "Ciprini", "given_name": "S." }, { "family_name": "Costa", "given_name": "E." }, { "family_name": "Del\u00a0Monte", "given_name": "E." }, { "family_name": "Di\u00a0Lalla", "given_name": "N." }, { "family_name": "Di\u00a0Marco", "given_name": "A.", "orcid": "0000-0003-0331-3259" }, { "family_name": "Donnarumma", "given_name": "I." }, { "family_name": "Doroshenko", "given_name": "V.", "orcid": "0000-0001-8162-1105" }, { "family_name": "Ehlert", "given_name": "S. R.", "orcid": "0000-0003-4420-2838" }, { "family_name": "Enoto", "given_name": "T.", "orcid": "0000-0003-1244-3100" }, { "family_name": "Evangelista", "given_name": "Y." }, { "family_name": "Fabiani", "given_name": "S." }, { "family_name": "Ferrazzoli", "given_name": "R." }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Gunji", "given_name": "S." }, { "family_name": "Hayashida", "given_name": "K." }, { "family_name": "Heyl", "given_name": "J." }, { "family_name": "Iwakiri", "given_name": "W.", "orcid": "0000-0002-0207-9010" }, { "family_name": "Jorstad", "given_name": "S. G.", "orcid": "0000-0001-6158-1708" }, { "family_name": "Kitaguchi", "given_name": "T." }, { "family_name": "Kolodziejczak", "given_name": "J. J." }, { "family_name": "La\u00a0Monaca", "given_name": "F.", "orcid": "0000-0001-8916-4156" }, { "family_name": "Latronico", "given_name": "L." }, { "family_name": "Liodakis", "given_name": "I.", "orcid": "0000-0001-9200-4006" }, { "family_name": "Maldera", "given_name": "S." }, { "family_name": "Manfreda", "given_name": "A." }, { "family_name": "Marscher", "given_name": "A. P.", "orcid": "0000-0001-7396-3332" }, { "family_name": "Mitsuishi", "given_name": "I." }, { "family_name": "Mizuno", "given_name": "T." }, { "family_name": "Ng", "given_name": "C.-Y." }, { "family_name": "O'Dell", "given_name": "S. L." }, { "family_name": "Omodei", "given_name": "N.", "orcid": "0000-0002-5448-7577" }, { "family_name": "Oppedisano", "given_name": "C." }, { "family_name": "Papitto", "given_name": "A.", "orcid": "0000-0001-6289-7413" }, { "family_name": "Pavlov", "given_name": "G. G." }, { "family_name": "Peirson", "given_name": "A. L.", "orcid": "0000-0001-6292-1911" }, { "family_name": "Perri", "given_name": "M." }, { "family_name": "Pesce-Rollins", "given_name": "M." }, { "family_name": "Pilia", "given_name": "M." }, { "family_name": "Possenti", "given_name": "A." }, { "family_name": "Poutanen", "given_name": "J.", "orcid": "0000-0002-0983-0049" }, { "family_name": "Ramsey", "given_name": "B. D." }, { "family_name": "Rankin", "given_name": "J. S.", "orcid": "0000-0002-8111-1444" }, { "family_name": "Ratheesh", "given_name": "A." }, { "family_name": "Romani", "given_name": "R. W.", "orcid": "0000-0001-6711-3286" }, { "family_name": "Sgr\u0161", "given_name": "C." }, { "family_name": "Slane", "given_name": "P. O.", "orcid": "0000-0002-6986-6756" }, { "family_name": "Soffitta", "given_name": "P.", "orcid": "0000-0003-1252-4891" }, { "family_name": "Spandre", "given_name": "G." }, { "family_name": "Tamagawa", "given_name": "T." }, { "family_name": "Tavecchio", "given_name": "F.", "orcid": "0000-0003-0256-0995" }, { "family_name": "Taverna", "given_name": "R." }, { "family_name": "Tawara", "given_name": "Y." }, { "family_name": "Tennant", "given_name": "A. F." }, { "family_name": "Thomas", "given_name": "N. E." }, { "family_name": "Trois", "given_name": "A.", "orcid": "0000-0002-3180-6002" }, { "family_name": "Tsygankov", "given_name": "S. S.", "orcid": "0000-0002-9679-0793" }, { "family_name": "Turolla", "given_name": "R." }, { "family_name": "Vink", "given_name": "J.", "orcid": "0000-0002-4708-4219" }, { "family_name": "Weisskopf", "given_name": "M. C." }, { "family_name": "Wu", "given_name": "K.", "orcid": "0000-0002-7568-8765" }, { "family_name": "Xie", "given_name": "F." }, { "family_name": "Zane", "given_name": "S." } ], "abstract": "We report on the first observation of a radio-quiet active galactic nucleus (AGN) in polarized X-rays: the Seyfert 1.9 galaxy MCG-05-23-16. This source was pointed at with the Imaging X-ray Polarimetry Explorer (IXPE) starting on 2022 May 14 for a net observing time of 486 ks, simultaneously with XMM-Newton (58 ks) and NuSTAR (83 ks). A polarization degree \u03a0 smaller than 4.7\u00a0per\u2009cent (at the 99\u00a0per\u2009cent confidence level) is derived in the 2\u20138\u00a0keV energy range, where emission is dominated by the primary component ascribed to the hot corona. The broad-band spectrum, inferred from a simultaneous fit to the IXPE, NuSTAR, and XMM-Newton data, is well reproduced by a power law with photon index \u0393\u00a0= 1.85\u00a0\u00b1\u00a00.01 and a high-energy cutoff E_C\u00a0= 120\u00a0\u00b1\u00a015\u00a0keV. A comparison with Monte Carlo simulations shows that a lamp-post and a conical geometry of the corona are consistent with the observed upper limit, a slab geometry is allowed only if the inclination angle of the system is less than 50\u00b0.", "doi": "10.1093/mnras/stac2634", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2022-11", "series_number": "4", "volume": "516", "issue": "4", "pages": "5907-5913" }, { "id": "authors:qj8hj-wmj69", "collection": "authors", "collection_id": "qj8hj-wmj69", "cite_using_url": "https://authors.library.caltech.edu/records/qj8hj-wmj69", "type": "article", "title": "The X-Ray Polarization View of Mrk 421 in an Average Flux State as Observed by the Imaging X-Ray Polarimetry Explorer", "author": [ { "family_name": "Di Gesu", "given_name": "Laura" }, { "family_name": "Donnarumma", "given_name": "Immacolata", "orcid": "0000-0002-4700-4549" }, { "family_name": "Tavecchio", "given_name": "Fabrizio", "orcid": "0000-0003-0256-0995" }, { "family_name": "Agudo", "given_name": "Iv\u00e1n", "orcid": "0000-0002-3777-6182" }, { "family_name": "Barnounin", "given_name": "Thibault" }, { "family_name": "Cibrario", "given_name": "Nicol\u00f2", "orcid": "0000-0003-3842-4493" }, { "family_name": "Di Lalla", "given_name": "Niccol\u00f2", "orcid": "0000-0002-7574-1298" }, { "family_name": "Di Marco", "given_name": "Alessandro", "orcid": "0000-0003-0331-3259" }, { "family_name": "Escudero", "given_name": "Juan", "orcid": "0000-0002-4131-655X" }, { "family_name": "Errando", "given_name": "Manel", "orcid": "0000-0002-1853-863X" }, { "family_name": "Jorstad", "given_name": "Svetlana G.", "orcid": "0000-0001-6158-1708" }, { "family_name": "Kim", "given_name": "Dawoon E.", "orcid": "0000-0001-5717-3736" }, { "family_name": "Kouch", "given_name": "Pouya M.", "orcid": "0000-0002-9328-2750" }, { "family_name": "Liodakis", "given_name": "Ioannis", "orcid": "0000-0001-9200-4006" }, { "family_name": "Lindfors", "given_name": "Elina" }, { "family_name": "Madejski", "given_name": "Grzegorz" }, { "family_name": "Marshall", "given_name": "Herman L.", "orcid": "0000-0002-6492-1293" }, { "family_name": "Marscher", "given_name": "Alan P.", "orcid": "0000-0001-7396-3332" }, { "family_name": "Middei", "given_name": "Riccardo", "orcid": "0000-0001-9815-9092" }, { "family_name": "Muleri", "given_name": "Fabio", "orcid": "0000-0003-3331-3794" }, { "family_name": "Myserlis", "given_name": "Ioannis", "orcid": "0000-0003-3025-9497" }, { "family_name": "Negro", "given_name": "Michela", "orcid": "0000-0002-6548-5622" }, { "family_name": "Omodei", "given_name": "Nicola", "orcid": "0000-0002-5448-7577" }, { "family_name": "Pacciani", "given_name": "Luigi", "orcid": "0000-0001-6897-5996" }, { "family_name": "Paggi", "given_name": "Alessandro", "orcid": "0000-0002-5646-2410" }, { "family_name": "Perri", "given_name": "Matteo", "orcid": "0000-0003-3613-4409" }, { "family_name": "Puccetti", "given_name": "Simonetta", "orcid": "0000-0002-2734-7835" }, { "family_name": "Antonelli", "given_name": "Lucio A.", "orcid": "0000-0002-5037-9034" }, { "family_name": "Bachetti", "given_name": "Matteo", "orcid": "0000-0002-4576-9337" }, { "family_name": "Baldini", "given_name": "Luca", "orcid": "0000-0002-9785-7726" }, { "family_name": "Baumgartner", "given_name": "Wayne H." }, { "family_name": "Bellazzini", "given_name": "Ronaldo", "orcid": "0000-0002-2469-7063" }, { "family_name": "Bianchi", "given_name": "Stefano", "orcid": "0000-0002-4622-4240" }, { "family_name": "Bongiorno", "given_name": "Stephen D." }, { "family_name": "Bonino", "given_name": "Raffaella", "orcid": "0000-0002-4264-1215" }, { "family_name": "Brez", "given_name": "Alessandro" }, { "family_name": "Bucciantini", "given_name": "Niccol\u00f2", "orcid": "0000-0002-8848-1392" }, { "family_name": "Capitanio", "given_name": "Fiamma", "orcid": "0000-0002-6384-3027" }, { "family_name": "Castellano", "given_name": "Simone" }, { "family_name": "Cavazzuti", "given_name": "Elisabetta", "orcid": "0000-0001-7150-9638" }, { "family_name": "Ciprini", "given_name": "Stefano", "orcid": "0000-0002-0712-2479" }, { "family_name": "Costa", "given_name": "Enrico", "orcid": "0000-0003-4925-8523" }, { "family_name": "De Rosa", "given_name": "Alessandra", "orcid": "0000-0001-5668-6863" }, { "family_name": "Del Monte", "given_name": "Ettore", "orcid": "0000-0002-3013-6334" }, { "family_name": "Doroshenko", "given_name": "Victor", "orcid": "0000-0001-8162-1105" }, { "family_name": "Dov\u010diak", "given_name": "Michal", "orcid": "0000-0003-0079-1239" }, { "family_name": "Ehlert", "given_name": "Steven R.", "orcid": "0000-0003-4420-2838" }, { "family_name": "Enoto", "given_name": "Teruaki", "orcid": "0000-0003-1244-3100" }, { "family_name": "Evangelista", "given_name": "Yuri", "orcid": "0000-0001-6096-6710" }, { "family_name": "Fabiani", "given_name": "Sergio", "orcid": "0000-0003-1533-0283" }, { "family_name": "Ferrazzoli", "given_name": "Riccardo", "orcid": "0000-0003-1074-8605" }, { "family_name": "Garcia", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Gunji", "given_name": "Shuichi", "orcid": "0000-0002-5881-2445" }, { "family_name": "Hayashida", "given_name": "Kiyoshi" }, { "family_name": "Heyl", "given_name": "Jeremy", "orcid": "0000-0001-9739-367X" }, { "family_name": "Iwakiri", "given_name": "Wataru", "orcid": "0000-0002-0207-9010" }, { "family_name": "Karas", "given_name": "Vladimir", "orcid": "0000-0002-5760-0459" }, { "family_name": "Kitaguchi", "given_name": "Takao" }, { "family_name": "Kolodziejczak", "given_name": "Jeffery J." }, { "family_name": "Krawczynski", "given_name": "Henric", "orcid": "0000-0002-1084-6507" }, { "family_name": "La Monaca", "given_name": "Fabio", "orcid": "0000-0001-8916-4156" }, { "family_name": "Latronico", "given_name": "Luca", "orcid": "0000-0002-0984-1856" }, { "family_name": "Maldera", "given_name": "Simone", "orcid": "0000-0002-0698-4421" }, { "family_name": "Manfreda", "given_name": "Alberto", "orcid": "0000-0002-0998-4953" }, { "family_name": "Marin", "given_name": "Fr\u00e9d\u00e9ric", "orcid": "0000-0003-4952-0835" }, { "family_name": "Marinucci", "given_name": "Andrea", "orcid": "0000-0002-2055-4946" }, { "family_name": "Massaro", "given_name": "Francesco", "orcid": "0000-0002-1704-9850" }, { "family_name": "Matt", "given_name": "Giorgio", "orcid": "0000-0002-2152-0916" }, { "family_name": "Mitsuishi", "given_name": "Ikuyuki", "orcid": "0000-0002-9901-233X" }, { "family_name": "Mizuno", "given_name": "Tsunefumi", "orcid": "0000-0001-7263-0296" }, { "family_name": "Ng", "given_name": "C.-Y.", "orcid": "0000-0002-5847-2612" }, { "family_name": "O'Dell", "given_name": "Stephen L.", "orcid": "0000-0002-1868-8056" }, { "family_name": "Oppedisano", "given_name": "Chiara", "orcid": "0000-0001-6194-4601" }, { "family_name": "Papitto", "given_name": "Alessandro", "orcid": "0000-0001-6289-7413" }, { "family_name": "Pavlov", "given_name": "George G.", "orcid": "0000-0002-7481-5259" }, { "family_name": "Peirson", "given_name": "Abel L.", "orcid": "0000-0001-6292-1911" }, { "family_name": "Pesce-Rollins", "given_name": "Melissa", "orcid": "0000-0003-1790-8018" }, { "family_name": "Petrucci", "given_name": "Pierre-Olivier" }, { "family_name": "Pilia", "given_name": "Maura", "orcid": "0000-0001-7397-8091" }, { "family_name": "Possenti", "given_name": "Andrea", "orcid": "0000-0001-5902-3731" }, { "family_name": "Poutanen", "given_name": "Juri", "orcid": "0000-0002-0983-0049" }, { "family_name": "Ramsey", "given_name": "Brian D.", "orcid": "0000-0003-1548-1524" }, { "family_name": "Rankin", "given_name": "John", "orcid": "0000-0002-9774-0560" }, { "family_name": "Ratheesh", "given_name": "Ajay", "orcid": "0000-0003-0411-4243" }, { "family_name": "Romani", "given_name": "Roger W.", "orcid": "0000-0001-6711-3286" }, { "family_name": "Sgr\u00f2", "given_name": "Carmelo", "orcid": "0000-0001-5676-6214" }, { "family_name": "Slane", "given_name": "Patrick", "orcid": "0000-0002-6986-6756" }, { "family_name": "Soffitta", "given_name": "Paolo", "orcid": "0000-0002-7781-4104" }, { "family_name": "Spandre", "given_name": "Gloria" }, { "family_name": "Tamagawa", "given_name": "Toru", "orcid": "0000-0002-8801-6263" }, { "family_name": "Taverna", "given_name": "Roberto", "orcid": "0000-0002-1768-618X" }, { "family_name": "Tawara", "given_name": "Yuzuru" }, { "family_name": "Tennant", "given_name": "Allyn F." }, { "family_name": "Thomas", "given_name": "Nicolas E." }, { "family_name": "Tombesi", "given_name": "Francesco", "orcid": "0000-0002-6562-8654" }, { "family_name": "Trois", "given_name": "Alessio", "orcid": "0000-0002-3180-6002" }, { "family_name": "Tsygankov", "given_name": "Sergey", "orcid": "0000-0002-9679-0793" }, { "family_name": "Turolla", "given_name": "Roberto", "orcid": "0000-0003-3977-8760" }, { "family_name": "Vink", "given_name": "Jacco", "orcid": "0000-0002-4708-4219" }, { "family_name": "Weisskopf", "given_name": "Martin C.", "orcid": "0000-0002-5270-4240" }, { "family_name": "Wu", "given_name": "Kinwah", "orcid": "0000-0002-7568-8765" }, { "family_name": "Xie", "given_name": "Fei", "orcid": "0000-0002-0105-5826" }, { "family_name": "Zane", "given_name": "Silvia", "orcid": "0000-0001-5326-880X" } ], "abstract": "

Particle acceleration mechanisms in supermassive black hole jets, such as shock acceleration, magnetic reconnection, and turbulence, are expected to have observable signatures in the multiwavelength polarization properties of blazars. The recent launch of the Imaging X-Ray Polarimetry Explorer (IXPE) enables us, for the first time, to use polarization in the X-ray band (2–8 keV) to probe the properties of the jet synchrotron emission in high-synchrotron-peaked BL Lac objects (HSPs). We report the discovery of X-ray linear polarization (degree Πx = 15% ± 2% and electric vector position angle ψ x = 35° ± 4°) from the jet of the HSP Mrk 421 in an average X-ray flux state. At the same time, the degree of polarization at optical, infrared, and millimeter wavelengths was found to be lower by at least a factor of 3. During the IXPE pointing, the X-ray flux of the source increased by a factor of 2.2, while the polarization behavior was consistent with no variability. The higher level of Πx compared to longer wavelengths, and the absence of significant polarization variability, suggest a shock is the most likely X-ray emission site in the jet of Mrk 421 during the observation. The multiwavelength polarization properties are consistent with an energy-stratified electron population, where the particles emitting at longer wavelengths are located farther from the acceleration site, where they experience a more disordered magnetic field.

", "doi": "10.3847/2041-8213/ac913a", "issn": "2041-8205", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal Letters", "publication_date": "2022-10-10", "series_number": "1", "volume": "938", "issue": "1", "pages": "L7" }, { "id": "authors:t1q6h-q8p58", "collection": "authors", "collection_id": "t1q6h-q8p58", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20221021-259555500.14", "type": "article", "title": "X-Ray Polarization Detection of Cassiopeia A with IXPE", "author": [ { "family_name": "Vink", "given_name": "Jacco", "orcid": "0000-0002-4708-4219", "clpid": "Vink-Jacco" }, { "family_name": "Prokhorov", "given_name": "Dmitry" }, { "family_name": "Ferrazzoli", "given_name": "Riccardo", "orcid": "0000-0003-1074-8605" }, { "family_name": "Slane", "given_name": "Patrick", "orcid": "0000-0002-6986-6756" }, { "family_name": "Zhou", "given_name": "Ping", "orcid": "0000-0002-5683-822X" }, { "family_name": "Asakura", "given_name": "Kazunori" }, { "family_name": "Baldini", "given_name": "Luca", "orcid": "0000-0002-9785-7726" }, { "family_name": "Bucciantini", "given_name": "Niccol\u00f3" }, { "family_name": "Costa", "given_name": "Enrico", "orcid": "0000-0003-4925-8523" }, { "family_name": "Di Marco", "given_name": "Alessandro", "orcid": "0000-0003-0331-3259" }, { "family_name": "Heyl", "given_name": "Jeremy", "orcid": "0000-0001-9739-367X" }, { "family_name": "Marin", "given_name": "Fr\u00e9d\u00e9ric", "orcid": "0000-0003-4952-0835" }, { "family_name": "Mizuno", "given_name": "Tsunefumi", "orcid": "0000-0001-7263-0296" }, { "family_name": "Ng", "given_name": "C.-Y." }, { "family_name": "Pesce-Rollins", "given_name": "Melissa", "orcid": "0000-0003-1790-8018" }, { "family_name": "Ramsey", "given_name": "Brian D." }, { "family_name": "Rankin", "given_name": "John", "orcid": "0000-0002-9774-0560" }, { "family_name": "Ratheesh", "given_name": "Ajay" }, { "family_name": "Sgr\u00f3", "given_name": "Carmelo", "orcid": "0000-0001-5676-6214" }, { "family_name": "Soffitta", "given_name": "Paolo", "orcid": "0000-0002-7781-4104" }, { "family_name": "Swartz", "given_name": "Douglas A." }, { "family_name": "Tamagawa", "given_name": "Toru" }, { "family_name": "Weisskopf", "given_name": "Martin C.", "orcid": "0000-0002-5270-4240" }, { "family_name": "Yang", "given_name": "Yi-Jung" }, { "family_name": "Bellazzini", "given_name": "Ronaldo", "orcid": "0000-0002-2469-7063" }, { "family_name": "Bonino", "given_name": "Raffaella", "orcid": "0000-0002-4264-1215" }, { "family_name": "Cavazzuti", "given_name": "Elisabetta", "orcid": "0000-0001-7150-9638" }, { "family_name": "Costamante", "given_name": "Luigi" }, { "family_name": "Di Lalla", "given_name": "Niccol\u00f3", "orcid": "0000-0002-7574-1298" }, { "family_name": "Latronico", "given_name": "Luca", "orcid": "0000-0002-0984-1856" }, { "family_name": "Maldera", "given_name": "Simone", "orcid": "0000-0002-0698-4421" }, { "family_name": "Manfreda", "given_name": "Alberto", "orcid": "0000-0002-0998-4953" }, { "family_name": "Massaro", "given_name": "Francesco", "orcid": "0000-0002-1704-9850" }, { "family_name": "Mitsuishi", "given_name": "Ikuyuki" }, { "family_name": "Omodei", "given_name": "Nicola", "orcid": "0000-0002-5448-7577" }, { "family_name": "Oppedisano", "given_name": "Chiara" }, { "family_name": "Zane", "given_name": "Silvia" }, { "family_name": "Agudo", "given_name": "Ivan", "orcid": "0000-0002-3777-6182" }, { "family_name": "Antonelli", "given_name": "Lucio A." }, { "family_name": "Bachetti", "given_name": "Matteo", "orcid": "0000-0002-4576-9337" }, { "family_name": "Baumgartner", "given_name": "Wayne H." }, { "family_name": "Bianchi", "given_name": "Stefano", "orcid": "0000-0002-4622-4240" }, { "family_name": "Bongiorno", "given_name": "Stephen D." }, { "family_name": "Brez", "given_name": "Alessandro" }, { "family_name": "Capitanio", "given_name": "Fiamma", "orcid": "0000-0002-6384-3027" }, { "family_name": "Castellano", "given_name": "Simone", "orcid": "0000-0003-1111-4292" }, { "family_name": "Ciprini", "given_name": "Stefano", "orcid": "0000-0002-0712-2479" }, { "family_name": "De Rosa", "given_name": "Alessandra", "orcid": "0000-0001-5668-6863" }, { "family_name": "Del Monte", "given_name": "Ettore", "orcid": "0000-0002-3013-6334" }, { "family_name": "Di Gesu", "given_name": "Laura" }, { "family_name": "Donnarumma", "given_name": "Immacolata" }, { "family_name": "Doroshenko", "given_name": "Victor", "orcid": "0000-0001-8162-1105" }, { "family_name": "Dov\u010diak", "given_name": "Michal", "orcid": "0000-0003-0079-1239" }, { "family_name": "Ehlert", "given_name": "Steven R.", "orcid": "0000-0003-4420-2838" }, { "family_name": "Enoto", "given_name": "Teruaki", "orcid": "0000-0003-1244-3100" }, { "family_name": "Evangelista", "given_name": "Yuri" }, { "family_name": "Fabiani", "given_name": "Sergio", "orcid": "0000-0003-1533-0283" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Gunji", "given_name": "Shuichi" }, { "family_name": "Hayashida", "given_name": "Kiyoshi" }, { "family_name": "Iwakiri", "given_name": "Wataru", "orcid": "0000-0002-0207-9010" }, { "family_name": "Jorstad", "given_name": "Svetlana G.", "orcid": "0000-0001-6158-1708" }, { "family_name": "Karas", "given_name": "Vladimir", "orcid": "0000-0002-5760-0459" }, { "family_name": "Kitaguchi", "given_name": "Takao" }, { "family_name": "Kolodziejczak", "given_name": "Jeffery J." }, { "family_name": "Krawczynski", "given_name": "Henric", "orcid": "0000-0002-1084-6507" }, { "family_name": "La Monaca", "given_name": "Fabio", "orcid": "0000-0001-8916-4156" }, { "family_name": "Liodakis", "given_name": "Ioannis", "orcid": "0000-0001-9200-4006" }, { "family_name": "Marinucci", "given_name": "Andrea", "orcid": "0000-0002-2055-4946" }, { "family_name": "Marscher", "given_name": "Alan P.", "orcid": "0000-0001-7396-3332" }, { "family_name": "Marshall", "given_name": "Herman L.", "orcid": "0000-0002-6492-1293" }, { "family_name": "Matt", "given_name": "Giorgio", "orcid": "0000-0002-2152-0916" }, { "family_name": "Muleri", "given_name": "Fabio", "orcid": "0000-0003-3331-3794" }, { "family_name": "O'Dell", "given_name": "Stephen L." }, { "family_name": "Papitto", "given_name": "Alessandro", "orcid": "0000-0001-6289-7413" }, { "family_name": "Pavlov", "given_name": "George G.", "orcid": "0000-0002-7481-5259" }, { "family_name": "Peirson", "given_name": "Abel L.", "orcid": "0000-0001-6292-1911" }, { "family_name": "Perri", "given_name": "Matteo" }, { "family_name": "Pilia", "given_name": "Maura", "orcid": "0000-0001-7397-8091" }, { "family_name": "Possenti", "given_name": "Andrea", "orcid": "0000-0001-5902-3731" }, { "family_name": "Poutanen", "given_name": "Juri", "orcid": "0000-0002-0983-0049" }, { "family_name": "Puccetti", "given_name": "Simonetta", "orcid": "0000-0002-2734-7835" }, { "family_name": "Romani", "given_name": "Roger W.", "orcid": "0000-0001-6711-3286" }, { "family_name": "Spandre", "given_name": "Gloria" }, { "family_name": "Tavecchio", "given_name": "Fabrizio", "orcid": "0000-0003-0256-0995" }, { "family_name": "Taverna", "given_name": "Roberto" }, { "family_name": "Tawara", "given_name": "Yuzuru" }, { "family_name": "Tennant", "given_name": "Allyn F." }, { "family_name": "Thomas", "given_name": "Nicolas E." }, { "family_name": "Tombesi", "given_name": "Francesco", "orcid": "0000-0002-6562-8654" }, { "family_name": "Trois", "given_name": "Alessio" }, { "family_name": "Tsygankov", "given_name": "Sergey", "orcid": "0000-0002-9679-0793" }, { "family_name": "Turolla", "given_name": "Roberto", "orcid": "0000-0003-3977-8760" }, { "family_name": "Wu", "given_name": "Kinwah" }, { "family_name": "Xie", "given_name": "Fei" } ], "abstract": "We report on a \u223c5\u03c3 detection of polarized 3\u20136 keV X-ray emission from the supernova remnant Cassiopeia A (Cas A) with the Imaging X-ray Polarimetry Explorer (IXPE). The overall polarization degree of 1.8% \u00b1 0.3% is detected by summing over a large region, assuming circular symmetry for the polarization vectors. The measurements imply an average polarization degree for the synchrotron component of \u223c2.5%, and close to 5% for the X-ray synchrotron-dominated forward shock region. These numbers are based on an assessment of the thermal and nonthermal radiation contributions, for which we used a detailed spatial-spectral model based on Chandra X-ray data. A pixel-by-pixel search for polarization provides a few tentative detections from discrete regions at the \u223c 3\u03c3 confidence level. Given the number of pixels, the significance is insufficient to claim a detection for individual pixels, but implies considerable turbulence on scales smaller than the angular resolution. Cas A's X-ray continuum emission is dominated by synchrotron radiation from regions within \u227210\u00b9\u2077 cm of the forward and reverse shocks. We find that (i) the measured polarization angle corresponds to a radially oriented magnetic field, similar to what has been inferred from radio observations; (ii) the X-ray polarization degree is lower than in the radio band (\u223c5%). Since shock compression should impose a tangential magnetic-field structure, the IXPE results imply that magnetic fields are reoriented within \u223c10\u00b9\u2077 cm of the shock. If the magnetic-field alignment is due to locally enhanced acceleration near quasi-parallel shocks, the preferred X-ray polarization angle suggests a size of 3 \u00d7 10\u00b9\u2076 cm for cells with radial magnetic fields.", "doi": "10.3847/1538-4357/ac8b7b", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2022-10-01", "series_number": "1", "volume": "938", "issue": "1", "pages": "Art. No. 40" }, { "id": "authors:s78yn-xb065", "collection": "authors", "collection_id": "s78yn-xb065", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220919-280781900", "type": "article", "title": "NuSTAR Observations of AGNs with Low Observed X-Ray to [O III] Luminosity Ratios: Heavily Obscured AGNs or Turned-off AGNs?", "author": [ { "family_name": "Saade", "given_name": "M. Lynne", "orcid": "0000-0001-7163-7015", "clpid": "Saade-M-Lynne" }, { "family_name": "Brightman", "given_name": "Murray", "orcid": "0000-0002-8147-2602", "clpid": "Brightman-M" }, { "family_name": "Stern", "given_name": "Daniel", "orcid": "0000-0003-2686-9241", "clpid": "Stern-D" }, { "family_name": "Malkan", "given_name": "Matthew A.", "orcid": "0000-0001-6919-1237", "clpid": "Malkan-Matthew-A" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" } ], "abstract": "Type 2 active galactic nuclei (AGNs) show signatures of accretion onto a supermassive black hole through strong, high-ionization, narrow emission lines extended on scales of hundreds to thousands of parsecs, but they lack the broad emission lines from close in to the black hole that characterize type 1 AGNs. The lack of broad emission could indicate obscuration of the innermost nuclear regions, or could indicate that the black hole is no longer strongly accreting. Since high-energy X-rays can penetrate thick obscuring columns, they have the power to distinguish these two scenarios. We present high-energy NuSTAR observations of nine Seyfert 2 AGNs from the Infrared Astronomical Satellite 12 \u03bcm survey, supplemented with low-energy X-ray observations from Chandra, XMM-Newton, and Swift. The galaxies were selected to have anomalously low observed 2\u201310 keV luminosities compared to their [O III] optical luminosities, a traditional diagnostic of heavily obscured AGNs, reaching into the Compton-thick regime for the highest hydrogen column densities (N_H > 1.5 \u00d7 10\u00b2\u2074 cm\u207b\u00b2). Based on updated [O III] luminosities and intrinsic X-ray luminosities based on physical modeling of the hard X-ray spectra, we find that one galaxy was misclassified as type 2 (NGC 5005) and most of the remaining AGNs are obscured, including three confirmed as Compton thick (IC 3639, NGC 1386, and NGC 3982). One galaxy, NGC 3627, appears to have recently deactivated. Compared to the original sample that the nine AGNs were selected from, this is a rate of approximately 1%. We also find a new X-ray changing-look AGN in NGC 6890.", "doi": "10.3847/1538-4357/ac88cf", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2022-09-10", "series_number": "2", "volume": "936", "issue": "2", "pages": "Art. No. 162" }, { "id": "authors:kwtgw-mtj42", "collection": "authors", "collection_id": "kwtgw-mtj42", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220923-941669700.13", "type": "article", "title": "The Tidal Disruption Event AT2021ehb: Evidence of Relativistic Disk Reflection, and Rapid Evolution of the Disk-Corona System", "author": [ { "family_name": "Yao", "given_name": "Yuhan", "orcid": "0000-0001-6747-8509", "clpid": "Yao-Yuhan" }, { "family_name": "Lu", "given_name": "Wenbin", "orcid": "0000-0002-1568-7461" }, { "family_name": "Guolo", "given_name": "Muryel", "orcid": "0000-0002-5063-0751" }, { "family_name": "Pasham", "given_name": "Dheeraj R.", "orcid": "0000-0003-1386-7861" }, { "family_name": "Gezari", "given_name": "Suvi", "orcid": "0000-0003-3703-5154" }, { "family_name": "Gilfanov", "given_name": "Marat" }, { "family_name": "Gendreau", "given_name": "Keith C.", "orcid": "0000-0001-7115-2819" }, { "family_name": "Harrison", "given_name": "Fiona A.", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" }, { "family_name": "Cenko", "given_name": "S. Bradley", "orcid": "0000-0003-1673-970X" }, { "family_name": "Kulkarni", "given_name": "S. R.", "orcid": "0000-0001-5390-8563", "clpid": "Kulkarni-S-R" }, { "family_name": "Miller", "given_name": "Jon M.", "orcid": "0000-0003-2869-7682" }, { "family_name": "Walton", "given_name": "Dominic J.", "orcid": "0000-0001-5819-3552" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Velzen", "given_name": "Sjoert van", "orcid": "0000-0002-3859-8074" }, { "family_name": "Alexander", "given_name": "Kate D.", "orcid": "0000-0002-8297-2473" }, { "family_name": "Miller-Jones", "given_name": "James C. A.", "orcid": "0000-0003-3124-2814" }, { "family_name": "Nicholl", "given_name": "Matt", "orcid": "0000-0002-2555-3192" }, { "family_name": "Hammerstein", "given_name": "Erica", "orcid": "0000-0002-5698-8703" }, { "family_name": "Medvedev", "given_name": "Pavel", "orcid": "0000-0002-9380-8708" }, { "family_name": "Stern", "given_name": "Daniel", "orcid": "0000-0003-2686-9241", "clpid": "Stern-D" }, { "family_name": "Ravi", "given_name": "Vikram", "orcid": "0000-0002-7252-5485", "clpid": "Ravi-Vikram" }, { "family_name": "Sunyaev", "given_name": "R." }, { "family_name": "Bloom", "given_name": "Joshua S.", "orcid": "0000-0002-7777-216X" }, { "family_name": "Graham", "given_name": "Matthew J.", "orcid": "0000-0002-3168-0139", "clpid": "Graham-M-J" }, { "family_name": "Kool", "given_name": "Erik C.", "orcid": "0000-0002-7252-3877" }, { "family_name": "Mahabal", "given_name": "Ashish A.", "orcid": "0000-0003-2242-0244", "clpid": "Mahabal-Ashish-A" }, { "family_name": "Masci", "given_name": "Frank J.", "orcid": "0000-0002-8532-9395", "clpid": "Masci-F-J" }, { "family_name": "Purdum", "given_name": "Josiah N.", "orcid": "0000-0003-1227-3738", "clpid": "Purdum-Josiah-N" }, { "family_name": "Rusholme", "given_name": "Ben", "orcid": "0000-0001-7648-4142", "clpid": "Rusholme-Benjamin" }, { "family_name": "Sharma", "given_name": "Yashvi", "orcid": "0000-0003-4531-1745", "clpid": "Sharma-Yashvi" }, { "family_name": "Smith", "given_name": "Roger", "orcid": "0000-0001-7062-9726", "clpid": "Smith-R-M" }, { "family_name": "Sollerman", "given_name": "Jesper", "orcid": "0000-0003-1546-6615" } ], "abstract": "We present X-ray, UV, optical, and radio observations of the nearby (\u224878 Mpc) tidal disruption event AT2021ehb/ZTF21aanxhjv during its first 430 days of evolution. AT2021ehb occurs in the nucleus of a galaxy hosting a \u2248 107 M_\u2299 black hole (M_(BH) inferred from host galaxy scaling relations). High-cadence Swift and Neutron Star Interior Composition Explorer (NICER) monitoring reveals a delayed X-ray brightening. The spectrum first undergoes a gradual soft \u2192 hard transition and then suddenly turns soft again within 3 days at \u03b4t \u2248 272 days during which the X-ray flux drops by a factor of 10. In the joint NICER+NuSTAR observation (\u03b4t = 264 days, harder state), we observe a prominent nonthermal component up to 30 keV and an extremely broad emission line in the iron K band. The bolometric luminosity of AT2021ehb reaches a maximum of 6.0^(+10.4)_(3.8)%L_(Edd) when the X-ray spectrum is the hardest. During the dramatic X-ray evolution, no radio emission is detected, the UV/optical luminosity stays relatively constant, and the optical spectra are featureless. We propose the following interpretations: (i) the soft \u2192 hard transition may be caused by the gradual formation of a magnetically dominated corona; (ii) hard X-ray photons escape from the system along solid angles with low scattering optical depth (\u223c a few) whereas the UV/optical emission is likely generated by reprocessing materials with much larger column density\u2014the system is highly aspherical; and (iii) the abrupt X-ray flux drop may be triggered by the thermal\u2013viscous instability in the inner accretion flow, leading to a much thinner disk.", "doi": "10.3847/1538-4357/ac898a", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2022-09-01", "series_number": "1", "volume": "937", "issue": "1", "pages": "8" }, { "id": "authors:k2nf6-grn16", "collection": "authors", "collection_id": "k2nf6-grn16", "cite_using_url": "https://authors.library.caltech.edu/records/k2nf6-grn16", "type": "article", "title": "Limits on X-Ray Polarization at the Core of Centaurus A as Observed with the Imaging X-Ray Polarimetry Explorer", "author": [ { "family_name": "Ehlert", "given_name": "Steven R.", "orcid": "0000-0003-1111-4292" }, { "family_name": "Ferrazzoli", "given_name": "Riccardo", "orcid": "0000-0003-1074-8605" }, { "family_name": "Marinucci", "given_name": "Andrea", "orcid": "0000-0002-2055-4946" }, { "family_name": "Marshall", "given_name": "Herman L.", "orcid": "0000-0002-6492-1293" }, { "family_name": "Middei", "given_name": "Riccardo", "orcid": "0000-0001-9815-9092" }, { "family_name": "Pacciani", "given_name": "Luigi", "orcid": "0000-0001-6897-5996" }, { "family_name": "Perri", "given_name": "Matteo", "orcid": "0000-0003-3613-4409" }, { "family_name": "Petrucci", "given_name": "Pierre-Olivier", "orcid": "0000-0001-6061-3480" }, { "family_name": "Puccetti", "given_name": "Simonetta", "orcid": "0000-0002-2734-7835" }, { "family_name": "Barnouin", "given_name": "Thibault", "orcid": "0000-0003-1340-5675" }, { "family_name": "Bianchi", "given_name": "Stefano", "orcid": "0000-0002-4622-4240" }, { "family_name": "Liodakis", "given_name": "Ioannis", "orcid": "0000-0001-9200-4006" }, { "family_name": "Madejski", "given_name": "Grzegorz" }, { "family_name": "Marin", "given_name": "Fr\u00e9d\u00e9ric", "orcid": "0000-0003-4952-0835" }, { "family_name": "Marscher", "given_name": "Alan P.", "orcid": "0000-0001-7396-3332" }, { "family_name": "Matt", "given_name": "Giorgio", "orcid": "0000-0002-2152-0916" }, { "family_name": "Poutanen", "given_name": "Juri", "orcid": "0000-0002-0983-0049" }, { "family_name": "Wu", "given_name": "Kinwah", "orcid": "0000-0002-7568-8765" }, { "family_name": "Agudo", "given_name": "Iv\u00e1n", "orcid": "0000-0002-3777-6182" }, { "family_name": "Antonelli", "given_name": "Lucio A.", "orcid": "0000-0002-5037-9034" }, { "family_name": "Bachetti", "given_name": "Matteo", "orcid": "0000-0002-4576-9337" }, { "family_name": "Baldini", "given_name": "Luca", "orcid": "0000-0002-9785-7726" }, { "family_name": "Baumgartner", "given_name": "Wayne H." }, { "family_name": "Bellazzini", "given_name": "Ronaldo", "orcid": "0000-0002-2469-7063" }, { "family_name": "Bongiorno", "given_name": "Stephen D." }, { "family_name": "Bonino", "given_name": "Raffaella", "orcid": "0000-0002-4264-1215" }, { "family_name": "Brez", "given_name": "Alessandro" }, { "family_name": "Bucciantini", "given_name": "Niccol\u00f3", "orcid": "0000-0002-8848-1392" }, { "family_name": "Capitanio", "given_name": "Fiamma", "orcid": "0000-0002-6384-3027" }, { "family_name": "Cavazzuti", "given_name": "Elisabetta", "orcid": "0000-0001-7150-9638" }, { "family_name": "Ciprini", "given_name": "Stefano", "orcid": "0000-0002-0712-2479" }, { "family_name": "Costa", "given_name": "Enrico", "orcid": "0000-0003-4925-8523" }, { "family_name": "De Rosa", "given_name": "Alessandra", "orcid": "0000-0001-5668-6863" }, { "family_name": "Del Monte", "given_name": "Ettore", "orcid": "0000-0002-3013-6334" }, { "family_name": "Di Gesu", "given_name": "Laura" }, { "family_name": "Di Lalla", "given_name": "Niccol\u00f3", "orcid": "0000-0002-7574-1298" }, { "family_name": "Di Marco", "given_name": "Alessandro", "orcid": "0000-0003-0331-3259" }, { "family_name": "Donnarumma", "given_name": "Immacolata", "orcid": "0000-0002-4700-4549" }, { "family_name": "Doroshenko", "given_name": "Victor", "orcid": "0000-0001-8162-1105" }, { "family_name": "Dov\u010diak", "given_name": "Michal", "orcid": "0000-0003-0079-1239" }, { "family_name": "Enoto", "given_name": "Teruaki", "orcid": "0000-0003-1244-3100" }, { "family_name": "Evangelista", "given_name": "Yuri", "orcid": "0000-0001-6096-6710" }, { "family_name": "Fabiani", "given_name": "Sergio", "orcid": "0000-0003-1533-0283" }, { "family_name": "Garcia", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Gunji", "given_name": "Shuichi" }, { "family_name": "Hayashida", "given_name": "Kiyoshi" }, { "family_name": "Heyl", "given_name": "Jeremy", "orcid": "0000-0001-9739-367X" }, { "family_name": "Iwakiri", "given_name": "Wataru", "orcid": "0000-0002-0207-9010" }, { "family_name": "Jorstad", "given_name": "Svetlana G.", "orcid": "0000-0001-6158-1708" }, { "family_name": "Karas", "given_name": "Vladimir", "orcid": "0000-0002-5760-0459" }, { "family_name": "Kitaguchi", "given_name": "Takao" }, { "family_name": "Kolodziejczak", "given_name": "Jeffery J." }, { "family_name": "Krawczynski", "given_name": "Henric", "orcid": "0000-0002-1084-6507" }, { "family_name": "La Monaca", "given_name": "Fabio", "orcid": "0000-0001-8916-4156" }, { "family_name": "Latronico", "given_name": "Luca", "orcid": "0000-0002-0984-1856" }, { "family_name": "Maldera", "given_name": "Simone", "orcid": "0000-0002-0698-4421" }, { "family_name": "Manfreda", "given_name": "Alberto", "orcid": "0000-0002-0998-4953" }, { "family_name": "Massaro", "given_name": "Francesco", "orcid": "0000-0002-1704-9850" }, { "family_name": "Mitsuishi", "given_name": "Ikuyuki", "orcid": "0000-0002-9901-233X" }, { "family_name": "Mizuno", "given_name": "Tsunefumi", "orcid": "0000-0001-7263-0296" }, { "family_name": "Muleri", "given_name": "Fabio", "orcid": "0000-0003-3331-3794" }, { "family_name": "Negro", "given_name": "Michela", "orcid": "0000-0002-6548-5622" }, { "family_name": "Ng", "given_name": "C.-Y.", "orcid": "0000-0002-5847-2612" }, { "family_name": "O'Dell", "given_name": "Stephen L.", "orcid": "0000-0002-1868-8056" }, { "family_name": "Omodei", "given_name": "Nicola", "orcid": "0000-0002-5448-7577" }, { "family_name": "Oppedisano", "given_name": "Chiara", "orcid": "0000-0001-6194-4601" }, { "family_name": "Papitto", "given_name": "Alessandro", "orcid": "0000-0001-6289-7413" }, { "family_name": "Pavlov", "given_name": "George G.", "orcid": "0000-0002-7481-5259" }, { "family_name": "Peirson", "given_name": "Abel L.", "orcid": "0000-0001-6292-1911" }, { "family_name": "Pesce-Rollins", "given_name": "Melissa", "orcid": "0000-0003-1790-8018" }, { "family_name": "Pilia", "given_name": "Maura", "orcid": "0000-0001-7397-8091" }, { "family_name": "Possenti", "given_name": "Andrea", "orcid": "0000-0001-5902-3731" }, { "family_name": "Ramsey", "given_name": "Brian D.", "orcid": "0000-0003-1548-1524" }, { "family_name": "Rankin", "given_name": "John", "orcid": "0000-0002-9774-0560" }, { "family_name": "Ratheesh", "given_name": "Ajay", "orcid": "0000-0003-0411-4243" }, { "family_name": "Romani", "given_name": "Roger W.", "orcid": "0000-0001-6711-3286" }, { "family_name": "Sgr\u00f2", "given_name": "Carmelo", "orcid": "0000-0001-5676-6214" }, { "family_name": "Slane", "given_name": "Patrick", "orcid": "0000-0002-6986-6756" }, { "family_name": "Soffitta", "given_name": "Paolo", "orcid": "0000-0002-7781-4104" }, { "family_name": "Spandre", "given_name": "Gloria" }, { "family_name": "Tamagawa", "given_name": "Toru" }, { "family_name": "Tavecchio", "given_name": "Fabrizio", "orcid": "0000-0003-0256-0995" }, { "family_name": "Taverna", "given_name": "Roberto", "orcid": "0000-0002-1768-618X" }, { "family_name": "Tawara", "given_name": "Yuzuru" }, { "family_name": "Tennant", "given_name": "Allyn F." }, { "family_name": "Thomas", "given_name": "Nicholas E." }, { "family_name": "Tombesi", "given_name": "Francesco", "orcid": "0000-0002-6562-8654" }, { "family_name": "Trois", "given_name": "Alessio", "orcid": "0000-0002-3180-6002" }, { "family_name": "Tsygankov", "given_name": "Sergey", "orcid": "0000-0002-9679-0793" }, { "family_name": "Turolla", "given_name": "Roberto", "orcid": "0000-0003-3977-8760" }, { "family_name": "Weisskopf", "given_name": "Martin C.", "orcid": "0000-0002-5270-4240" }, { "family_name": "Xie", "given_name": "Fei", "orcid": "0000-0002-0105-5826" }, { "family_name": "Zane", "given_name": "Silvia", "orcid": "0000-0001-5326-880X" }, { "family_name": "Rodi", "given_name": "James" }, { "family_name": "Jourdain", "given_name": "Elisabeth", "orcid": "0000-0001-9932-3288" }, { "family_name": "Roques", "given_name": "Jean-Pierre", "orcid": "0000-0002-6529-4121" }, { "literal": "(IXPE Collaboration)" } ], "abstract": "

We present measurements of the polarization of X-rays in the 2–8 keV band from the nucleus of the radio galaxy Centaurus A (Cen A), using a 100 ks observation from the Imaging X-ray Polarimetry Explorer (IXPE). Nearly simultaneous observations of Cen A were also taken with the Swift, NuSTAR, and INTEGRAL observatories. No statistically significant degree of polarization is detected with IXPE. These observations have a minimum detectable polarization at 99% confidence (MDP\u2089\u2089) of 6.5% using a weighted, spectral model-independent calculation in the 2–8 keV band. The polarization angle ψ is consequently unconstrained. Spectral fitting across three orders of magnitude in X-ray energy (0.3–400 keV) demonstrates that the SED of Cen A is well described by a simple power law with moderate intrinsic absorption (N_H ∼ 10²³ cm\u207b²) and a Fe Kα emission line, although a second unabsorbed power law is required to account for the observed spectrum at energies below 2 keV. This spectrum suggests that the reprocessing material responsible for this emission line is optically thin and distant from the central black hole. Our upper limits on the X-ray polarization are consistent with the predictions of Compton scattering, although the specific seed photon population responsible for the production of the X-rays cannot be identified. The low polarization degree, variability in the core emission, and the relative lack of variability in the Fe Kα emission line support a picture where electrons are accelerated in a region of highly disordered magnetic fields surrounding the innermost jet.

", "doi": "10.3847/1538-4357/ac8056", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2022-08-20", "series_number": "2", "volume": "935", "issue": "2", "pages": "116" }, { "id": "authors:8rewm-47333", "collection": "authors", "collection_id": "8rewm-47333", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220908-183016086", "type": "article", "title": "The Long-stable Hard State of XTE J1752-223 and the Disk Truncation Dilemma", "author": [ { "family_name": "Connors", "given_name": "Riley M. T.", "orcid": "0000-0002-8908-759X", "clpid": "Connors-Riley-M-T" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Tomsick", "given_name": "John", "orcid": "0000-0001-5506-9855", "clpid": "Tomsick-John-A" }, { "family_name": "Mastroserio", "given_name": "Guglielmo", "orcid": "0000-0003-4216-7936", "clpid": "Mastroserio-Guglielmo" }, { "family_name": "Grinberg", "given_name": "Victoria", "orcid": "0000-0003-2538-0188", "clpid": "Grinberg-Victoria" }, { "family_name": "Steiner", "given_name": "James F.", "orcid": "0000-0002-5872-6061", "clpid": "Steiner-James-F" }, { "family_name": "Jiang", "given_name": "Jiachen", "orcid": "0000-0002-9639-4352", "clpid": "Jiang-Jiachen" }, { "family_name": "Fabian", "given_name": "Andrew C.", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-Andrew-C" }, { "family_name": "Parker", "given_name": "Michael L.", "orcid": "0000-0002-8466-7317", "clpid": "Parker-Michael-L" }, { "family_name": "Harrison", "given_name": "Fiona", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" }, { "family_name": "Hare", "given_name": "Jeremy", "orcid": "0000-0002-8548-482X", "clpid": "Hare-Jeremy" }, { "family_name": "Mallick", "given_name": "Labani", "orcid": "0000-0001-8624-9162", "clpid": "Mallick-Labani" }, { "family_name": "Lazar", "given_name": "Hadar", "orcid": "0000-0002-2752-9524", "clpid": "Lazar-Hadar" } ], "abstract": "The degree to which the thin accretion disks of black hole X-ray binaries are truncated during hard spectral states remains a contentious open question in black hole astrophysics. During its singular observed outburst in 2009\u20132010, the black hole X-ray binary XTE J1752\u2212223 spent \u223c1 month in a long-stable hard spectral state at a luminosity of \u223c0.02\u20130.1 L_Edd. It was observed with 56 RXTE pointings during this period, with simultaneous Swift-XRT daily coverage during the first 10 days of the RXTE observations. While reflection modeling has been extensively explored in the analysis of these data, there is disagreement surrounding the geometry of the accretion disk and corona implied by the reflection features. We reexamine the combined, high signal-to-noise, simultaneous Swift and RXTE observations, and perform extensive reflection modeling with the latest relxill suite of reflection models, including newer high disk density models. We show that reflection modeling requires that the disk be within \u223c5 R_ISCO during the hard spectral state, while weaker constraints from the thermal disk emission imply higher truncation (R_in = 6\u201380 R_ISCO). We also explore more complex coronal continuum models, allowing for two Comptonization components instead of one, and show that the reflection features still require only a mildly truncated disk. Finally we present a full comparison of our results to previous constraints found from analyses of the same data set.", "doi": "10.3847/1538-4357/ac7ff2", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2022-08-01", "series_number": "2", "volume": "935", "issue": "2", "pages": "118" }, { "id": "authors:kjvma-3xb56", "collection": "authors", "collection_id": "kjvma-3xb56", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220802-742158000", "type": "article", "title": "The effect of returning radiation on relativistic reflection", "author": [ { "family_name": "Dauser", "given_name": "T.", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-Thomas" }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Joyce", "given_name": "A.", "clpid": "Joyce-A." }, { "family_name": "Licklederer", "given_name": "S.", "orcid": "0000-0002-3720-4408", "clpid": "Licklederer-Stefan" }, { "family_name": "Connors", "given_name": "R. M. T.", "orcid": "0000-0002-8908-759X", "clpid": "Connors-Riley-M-T" }, { "family_name": "Ingram", "given_name": "A.", "orcid": "0000-0002-5311-9078", "clpid": "Ingram-Adam-R" }, { "family_name": "Reynolds", "given_name": "C. S.", "orcid": "0000-0002-1510-4860", "clpid": "Reynolds-Christopher-S" }, { "family_name": "Wilms", "given_name": "J.", "orcid": "0000-0003-2065-5410", "clpid": "Wilms-J\u00f6rn" } ], "abstract": "We study the effect of returning radiation on the shape of the X-ray reflection spectrum in the case of thin accretion discs. We show that the returning radiation mainly influences the observed reflection spectrum for a large black hole spin (a > 0.9) and a compact primary source of radiation close to the black hole at height h < 5r_g, and that it dominates the reflected flux for extreme values of spin and compactness. The main effect of the returning radiation is to increase the irradiating flux on to the outer parts of the accretion disc, leading to stronger reflection and a flatter overall emissivity profile. By analysing simulated observations we show that neglecting returning radiation in existing studies of reflection-dominated sources has likely resulted in overestimating the height of the corona above the black hole. An updated version of the publicly available relxill suite of relativistic reflection models which includes returning radiation is also presented.", "doi": "10.1093/mnras/stac1593", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2022-08", "series_number": "3", "volume": "514", "issue": "3", "pages": "3965-3983" }, { "id": "authors:fqq2d-4xs75", "collection": "authors", "collection_id": "fqq2d-4xs75", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220726-998023000", "type": "article", "title": "Evolution of a Relativistic Outflow and X-Ray Corona in the Extreme Changing-look AGN 1ES 1927+654", "author": [ { "family_name": "Masterson", "given_name": "Megan", "orcid": "0000-0003-4127-0739", "clpid": "Masterson-Megan" }, { "family_name": "Kara", "given_name": "Erin", "orcid": "0000-0003-0172-0854", "clpid": "Kara-Erin" }, { "family_name": "Ricci", "given_name": "Claudio", "orcid": "0000-0001-5231-2645", "clpid": "Ricci-Claudio" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Fabian", "given_name": "Andrew C.", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-Andrew-C" }, { "family_name": "Pinto", "given_name": "Ciro", "orcid": "0000-0003-2532-7379", "clpid": "Pinto-C" }, { "family_name": "Kosec", "given_name": "Peter", "orcid": "0000-0003-4511-8427", "clpid": "Kosec-Peter" }, { "family_name": "Remillard", "given_name": "Ronald A.", "orcid": "0000-0003-4815-0481", "clpid": "Remillard-Ronald-A" }, { "family_name": "Loewenstein", "given_name": "Michael", "orcid": "0000-0002-1661-4029", "clpid": "Loewenstein-Michael" }, { "family_name": "Trakhtenbrot", "given_name": "Benny", "orcid": "0000-0002-3683-7297", "clpid": "Trakhtenbrot-Benny" }, { "family_name": "Arcavi", "given_name": "Iair", "orcid": "0000-0001-7090-4898", "clpid": "Arcavi-Iair" } ], "abstract": "1ES 1927+654 is a paradigm-defying active galactic nucleus (AGN) and one of the most peculiar X-ray nuclear transients. In early 2018, this well-known AGN underwent a changing-look event, in which broad optical emission lines appeared and the optical flux increased. Yet, by 2018 July, the X-ray flux had dropped by over two orders of magnitude, indicating a dramatic change in the inner accretion flow. With three years of observations with NICER, XMM-Newton, and NuSTAR, we present the X-ray evolution of 1ES 1927+654, which can be broken down into three phases: (1) an early super-Eddington phase with rapid variability in X-ray luminosity and spectral parameters, (2) a stable super-Eddington phase at the peak X-ray luminosity, and (3) a steady decline back to the pre-outburst luminosity and spectral parameters. For the first time, we witnessed the formation of the X-ray corona, as the X-ray spectrum transitioned from thermally dominated to primarily Comptonized. We also track the evolution of the prominent, broad 1 keV feature in the early X-ray spectra and show that this feature can be modeled with blueshifted reflection (z = \u22120.33) from a single-temperature blackbody irradiating spectrum using xillverTDE, a new flavor of the xillver models. Thus, we propose that the 1 keV feature could arise from reflected emission off the base of an optically thick outflow from a geometrically thick, super-Eddington inner accretion flow, connecting the inner accretion flow with outflows launched during extreme accretion events (e.g., tidal disruption events). Lastly, we compare 1ES 1927+654 to other nuclear transients and discuss applications of xillverTDE to super-Eddington accretors.", "doi": "10.3847/1538-4357/ac76c0", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2022-07-20", "series_number": "1", "volume": "934", "issue": "1", "pages": "Art. No. 35" }, { "id": "authors:z1wnp-0py89", "collection": "authors", "collection_id": "z1wnp-0py89", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220709-032308938", "type": "article", "title": "High-density disc reflection spectroscopy of low-mass active galactic nuclei", "author": [ { "family_name": "Mallick", "given_name": "L.", "orcid": "0000-0001-8624-9162", "clpid": "Mallick-Labani" }, { "family_name": "Fabian", "given_name": "A. C.", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-Andrew-C" }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Tomsick", "given_name": "J. A.", "orcid": "0000-0001-5506-9855", "clpid": "Tomsick-John-A" }, { "family_name": "Parker", "given_name": "M. L.", "orcid": "0000-0002-8466-7317", "clpid": "Parker-Michael-L" }, { "family_name": "Dauser", "given_name": "T.", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-Thomas" }, { "family_name": "Wilkins", "given_name": "D. R.", "orcid": "0000-0002-4794-5998", "clpid": "Wilkins-Dan-R" }, { "family_name": "De Marco", "given_name": "B.", "orcid": "0000-0003-2743-6632", "clpid": "De-Marco-Barbara" }, { "family_name": "Steiner", "given_name": "J. F.", "orcid": "0000-0002-5872-6061", "clpid": "Steiner-James-F" }, { "family_name": "Connors", "given_name": "R. M. T.", "orcid": "0000-0002-8908-759X", "clpid": "Connors-Riley-M-T" }, { "family_name": "Mastroserio", "given_name": "G.", "orcid": "0000-0003-4216-7936", "clpid": "Mastroserio-Guglielmo" }, { "family_name": "Markowitz", "given_name": "A. G.", "orcid": "0000-0002-2173-0673", "clpid": "Markowitz-Alex" }, { "family_name": "Pinto", "given_name": "C.", "orcid": "0000-0003-2532-7379", "clpid": "Pinto-Ciro" }, { "family_name": "Alston", "given_name": "W. N.", "orcid": "0000-0003-2658-6559", "clpid": "Alston-William-N" }, { "family_name": "Lohfink", "given_name": "A. M.", "clpid": "Lohfink-A-M" }, { "family_name": "Gandhi", "given_name": "P.", "orcid": "0000-0003-3105-2615", "clpid": "Gandhi-Poshak" } ], "abstract": "The standard alpha-disc model predicts an anticorrelation between the density of the inner accretion disc and the black hole mass times square of the accretion rate, as seen in higher mass (M_(BH) > 10\u2076\u2009M_\u2299) active galactic nuclei (AGNs). In this work, we test the predictions of the alpha-disc model and study the properties of the inner accretion flow for the low-mass end (M_(BH) \u2248 10\u2075\u207b\u2076\u2009M_\u2299) of AGNs. We utilize a new high-density disc reflection model where the density parameter varies from n\u2091 = 10\u00b9\u2075 to 10\u00b2\u2070 cm\u207b\u00b3 and apply it to the broad-band X-ray (0.3\u201310 keV) spectra of the low-mass AGN sample. The sources span a wide range of Eddington fractions and are consistent with being sub-Eddington or near-Eddington. The X-ray spectra reveal a soft X-ray excess below \u223c1.5 keV which is well modelled by high-density reflection from an ionized accretion disc of density ne \u223c 10\u00b9\u2078 cm\u207b\u00b3 on average. The results suggest a radiation pressure-dominated disc with an average of 70 per cent fraction of the disc power transferred to the corona, consistent with that observed in higher mass AGNs. We show that the disc density higher than 10\u00b9\u2075 cm\u207b\u00b3 can result from the radiation pressure compression when the disc surface does not hold a strong magnetic pressure gradient. We find tentative evidence for a drop in black hole spin at low-mass regimes.", "doi": "10.1093/mnras/stac990", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2022-07", "series_number": "3", "volume": "513", "issue": "3", "pages": "4361-4379" }, { "id": "authors:n1x5b-84369", "collection": "authors", "collection_id": "n1x5b-84369", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220802-742430000", "type": "article", "title": "Analysis of the reflection spectra of MAXI J1535-571 in the hard and intermediate states", "author": [ { "family_name": "Dong", "given_name": "Yanting", "orcid": "0000-0002-4584-0463", "clpid": "Dong-Yanting" }, { "family_name": "Liu", "given_name": "Zhu", "orcid": "0000-0003-3014-8762", "clpid": "Liu-Zhu-ASTRO" }, { "family_name": "Tuo", "given_name": "Youli", "orcid": "0000-0003-3127-0110", "clpid": "Tuo-Youli" }, { "family_name": "Steiner", "given_name": "James F.", "orcid": "0000-0002-5872-6061", "clpid": "Steiner-James-F" }, { "family_name": "Ge", "given_name": "Mingyu", "orcid": "0000-0002-3776-4536", "clpid": "Gu-Mingyu" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Cao", "given_name": "Xinwu", "orcid": "0000-0002-2355-3498", "clpid": "Cao-Xinwu" } ], "abstract": "We report results on the joint-fit of the NuSTAR and HXMT data for the black hole X-ray binary candidate MAXI J1535-571. The observations were obtained in 2017 when the source evolved through the hard, hard-intermediate, and soft-intermediate states over the rising phase of the outburst. After subtracting continuum components, X-ray reflection signatures are clearly showed in those observations. By modelling the relativistic reflection in detail, we find that the inner radius Rin is relatively stable with R_(in) \u2272 1.55R_g during the three states, which implies that the inner radius likely extends to the innermost stable circular orbit even in the bright hard state. When adopting R_(in)\u00a0= R_(ISCO), the spin parameter is constrained to be 0.985_(-0.004)^(+0.002) at 90\u00a0per\u2009cent confidence (statistical only). The best-fitting results reveal that the inclination of the inner accretion disc is \u223c70\u201374 deg, which notably conflicts with the apparent orientation of the ballistic jet (\u226445 deg). In addition, both the photon index and the electron temperature increase during the transition from hard to soft state. It seems that the corona evolves from dense low-temperature in the low/hard state to tenuous high-temperature after the state transition, which indicates that the state transition is accompanied by the evolution of the coronal properties.", "doi": "10.1093/mnras/stac1466", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2022-07", "series_number": "1", "volume": "514", "issue": "1", "pages": "1422-1432" }, { "id": "authors:tnxbk-2xz73", "collection": "authors", "collection_id": "tnxbk-2xz73", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220525-90819000", "type": "article", "title": "Ejection\u2013accretion connection in NLS1 AGN 1H 1934-063", "author": [ { "family_name": "Xu", "given_name": "Y.", "orcid": "0000-0002-2523-5485", "clpid": "Xu-Yerong" }, { "family_name": "Pinto", "given_name": "C.", "orcid": "0000-0003-2532-7379", "clpid": "Pinto-Ciro" }, { "family_name": "Kara", "given_name": "E.", "orcid": "0000-0003-0172-0854", "clpid": "Kara-Erin" }, { "family_name": "Masterson", "given_name": "M.", "orcid": "0000-0003-4127-0739", "clpid": "Masterson-Megan" }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Fabian", "given_name": "A. C.", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-Andrew-C" }, { "family_name": "Parker", "given_name": "M. L.", "orcid": "0000-0002-8466-7317", "clpid": "Parker-Michael-L" }, { "family_name": "Barret", "given_name": "D.", "orcid": "0000-0002-0393-9190", "clpid": "Barret-Didier" }, { "family_name": "Alston", "given_name": "W. N.", "orcid": "0000-0003-2658-6559", "clpid": "Alston-William-N" }, { "family_name": "Cusumano", "given_name": "G.", "orcid": "0000-0002-8151-1990", "clpid": "Cusumano-Giancarlo" } ], "abstract": "Accretion and ejection of matter in active galactic nuclei (AGNs) are tightly connected phenomena and represent fundamental mechanisms regulating the growth of the central supermassive black hole and the evolution of the host galaxy. However, the exact physical processes involved are not yet fully understood. We present a high-resolution spectral analysis of a simultaneous XMM\u2013Newton and NuSTAR observation of the narrow line Seyfert 1 (NLS1) AGN 1H 1934-063, during which the X-ray flux dropped by a factor of \u223c6 and subsequently recovered within 140 kiloseconds. By means of the time-resolved and flux-resolved X-ray spectroscopy, we discover a potentially variable warm absorber and a relatively stable ultra-fast outflow (UFO, \u03bd_(UFO) ~ -0.075 c) with a mild ionization state (log \u03be/erg cm s\u207b\u00b9) ~ 1.6). The detected emission lines (especially a strong and broad feature around 1\u2009keV) are of unknown origin and cannot be explained with emission from plasmas in photo- or collisional-ionization equilibrium. Such emission lines could be well described by a strongly blueshifted (z \u223c \u22120.3) secondary reflection off the base of the equatorial outflows, which may reveal the link between the reprocessing of the inner accretion flow photons and the ejection. However, this scenario although being very promising is only tentative and will be tested with future observations.", "doi": "10.1093/mnras/stac1058", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2022-06", "series_number": "2", "volume": "513", "issue": "2", "pages": "1910-1924" }, { "id": "authors:btdzb-xv217", "collection": "authors", "collection_id": "btdzb-xv217", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220512-561107000", "type": "article", "title": "The NICER \"Reverberation Machine\": A Systematic Study of Time Lags in Black Hole X-Ray Binaries", "author": [ { "family_name": "Wang", "given_name": "Jingyi", "orcid": "0000-0002-1742-2125", "clpid": "Wang-Jingyi" }, { "family_name": "Kara", "given_name": "Erin", "orcid": "0000-0003-0172-0854", "clpid": "Kara-Erin" }, { "family_name": "Lucchini", "given_name": "Matteo", "orcid": "0000-0002-2235-3347", "clpid": "Lucchini-Matteo" }, { "family_name": "Ingram", "given_name": "Adam", "orcid": "0000-0002-5311-9078", "clpid": "Ingram-Adam" }, { "family_name": "van der Klis", "given_name": "Michiel", "orcid": "0000-0003-0070-9872", "clpid": "van-der-Klis-Michiel" }, { "family_name": "Mastroserio", "given_name": "Guglielmo", "orcid": "0000-0003-4216-7936", "clpid": "Mastroserio-Guglielmo" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-Thomas" }, { "family_name": "Connors", "given_name": "Riley", "orcid": "0000-0002-8908-759X", "clpid": "Connors-Riley-M-T" }, { "family_name": "Fabian", "given_name": "Andrew C.", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-Andrew-C" }, { "family_name": "Steiner", "given_name": "James F.", "orcid": "0000-0002-5872-6061", "clpid": "Steiner-James-F" }, { "family_name": "Remillard", "given_name": "Ron A.", "orcid": "0000-0003-4815-0481", "clpid": "Remillard-Ron-A" }, { "family_name": "Cackett", "given_name": "Edward M.", "orcid": "0000-0002-8294-9281", "clpid": "Cackett-Edward-M" }, { "family_name": "Uttley", "given_name": "Phil", "orcid": "0000-0001-9355-961X", "clpid": "Uttley-Philip" }, { "family_name": "Altamirano", "given_name": "Diego", "orcid": "0000-0002-3422-0074", "clpid": "Altamirano-Diego" } ], "abstract": "We perform the first systematic search of all NICER archival observations of black hole (and candidate) low-mass X-ray binaries for signatures of reverberation. Reverberation lags result from the light travel time difference between the direct coronal emission and the reflected disk component, and therefore their properties are a useful probe of the disk-corona geometry. We detect new signatures of reverberation lags in eight sources, increasing the total sample from three to 11, and study the evolution of reverberation lag properties as the sources evolve in outbursts. We find that in all of the nine sources with more than one reverberation lag detection, the reverberation lags become longer and dominate at lower Fourier frequencies during the hard-to-soft state transition. This result shows that the evolution in reverberation lags is a global property of the state transitions of black hole low-mass X-ray binaries, which is valuable in constraining models of such state transitions. The reverberation lag evolution suggests that the corona is the base of a jet that vertically expands and/or gets ejected during state transition. We also discover that in the hard state, the reverberation lags get shorter, just as the quasiperiodic oscillations (QPOs) move to higher frequencies, but then in the state transition, while the QPOs continue to higher frequencies, the lags get longer. We discuss the implications of the coronal geometry and physical models of QPOs in light of this new finding.", "doi": "10.3847/1538-4357/ac6262", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2022-05-01", "series_number": "1", "volume": "930", "issue": "1", "pages": "Art. No. 18" }, { "id": "authors:rm1ce-nee03", "collection": "authors", "collection_id": "rm1ce-nee03", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220419-783347800", "type": "article", "title": "Detailed analysis on the reflection component for the black hole candidate MAXI J1348-630", "author": [ { "family_name": "Jia", "given_name": "Nan", "orcid": "0000-0002-5487-880X", "clpid": "Jia-Nan" }, { "family_name": "Zhao", "given_name": "Xueshan", "clpid": "Zhao-Xueshan" }, { "family_name": "Gou", "given_name": "Lijun", "clpid": "Gou-Lijun" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Liao", "given_name": "Zhenxuan", "orcid": "0000-0003-2221-0490", "clpid": "Liao-Zhenxuan" }, { "family_name": "Feng", "given_name": "Ye", "orcid": "0000-0002-6961-8082", "clpid": "Feng-Ye" }, { "family_name": "Li", "given_name": "Yufeng", "clpid": "Li-Yufeng" }, { "family_name": "Wang", "given_name": "Yuan", "orcid": "0000-0001-6657-8401", "clpid": "Wang-Yuan" }, { "family_name": "Li", "given_name": "Huixian", "clpid": "Li-Huixian" }, { "family_name": "Wu", "given_name": "Jianfeng", "orcid": "0000-0001-7349-4695", "clpid": "Wu-Jianfeng" } ], "abstract": "The black hole candidate MAXI J1348-630 was discovered in 2019 January 26, with the Gas Slit Camera (GSC) on-board MAXI. We report a detailed spectral analysis of this source by using the archived data of NuSTAR. A total of nine observations covered the complete outburst evolution of MAXI J1348-630 from the hard state to the soft state and finally back to the hard state. Additionally, the intermediate state is found in the transition from the hard state to the soft state. We use the state-of-the-art reflection model relxill family to fit all the nine spectra, and the spectra from two focal plane module detectors of NuSTAR are jointly fitted for each observation. In particular, we concentrate on the results of the black hole spin parameter and the inclination of the accretion disc. Based on the analysis of the inner radius of the accretion disc, we obtain the spin parameter a\u2217 = 0.78^(+0.04)_(\u22120.04)\u2060, and the inclination angle of the inner disc i = 29.2^(+0.3)_(\u22120.5)\u00b0. Furthermore, we also find that when the black hole is in the hard state, the accretion disc would show a significant truncation. The high iron abundance and ionization of the accretion disc obtained in the fitting results can be possibly explained by the high density of the accretion disc.", "doi": "10.1093/mnras/stac121", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2022-04", "series_number": "3", "volume": "511", "issue": "3", "pages": "3125-3132" }, { "id": "authors:hz6p5-eta78", "collection": "authors", "collection_id": "hz6p5-eta78", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220304-000054911", "type": "article", "title": "MAXI and NuSTAR Observations of the Faint X-Ray Transient MAXI J1848-015 in the GLIMPSE-C01 Cluster", "author": [ { "family_name": "Pike", "given_name": "Sean N.", "orcid": "0000-0002-8403-0041", "clpid": "Pike-Sean-N" }, { "family_name": "Negoro", "given_name": "Hitoshi", "orcid": "0000-0003-0939-1178", "clpid": "Negoro-Hitoshi" }, { "family_name": "Tomsick", "given_name": "John A.", "orcid": "0000-0001-5506-9855", "clpid": "Tomsick-John-A" }, { "family_name": "Bachetti", "given_name": "Matteo", "orcid": "0000-0002-4576-9337", "clpid": "Bachetti-Matteo" }, { "family_name": "Brumback", "given_name": "McKinley", "orcid": "0000-0002-4024-6967", "clpid": "Brumback-McKinley-C" }, { "family_name": "Connors", "given_name": "Riley M. T.", "orcid": "0000-0002-8908-759X", "clpid": "Connors-Riley-M-T" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Grefenstette", "given_name": "Brian", "orcid": "0000-0002-1984-2932", "clpid": "Grefenstette-Brian-W" }, { "family_name": "Hare", "given_name": "Jeremy", "orcid": "0000-0002-8548-482X", "clpid": "Hare-Jeremy" }, { "family_name": "Harrison", "given_name": "Fiona A.", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" }, { "family_name": "Jaodand", "given_name": "Amruta", "orcid": "0000-0002-3850-6651", "clpid": "Jaodand-Amruta-D" }, { "family_name": "Ludlam", "given_name": "R. M.", "orcid": "0000-0002-8961-939X", "clpid": "Ludlam-Renee-M" }, { "family_name": "Mastroserio", "given_name": "Guglielmo", "orcid": "0000-0003-4216-7936", "clpid": "Mastroserio-Guglielmo" }, { "family_name": "Mihara", "given_name": "Tatehiro", "orcid": "0000-0002-6337-7943", "clpid": "Mihara-Tatehiro" }, { "family_name": "Shidatsu", "given_name": "Megumi", "orcid": "0000-0001-8195-6546", "clpid": "Shidatsu-Megumi" }, { "family_name": "Sugizaki", "given_name": "Mutsumi", "orcid": "0000-0002-1190-0720", "clpid": "Sugizaka-Mutsumi" }, { "family_name": "Takagi", "given_name": "Ryohei", "clpid": "Takagi-Ryohei" } ], "abstract": "We present the results of Monitor of All-sky X-ray Image (MAXI) monitoring and two Nuclear Spectroscopic Telescope Array (NuSTAR) observations of the recently discovered faint X-ray transient MAXI J1848015. Analysis of the MAXI light curve shows that the source underwent a rapid flux increase beginning on 2020 December 20, followed by a rapid decrease in flux after only \u223c5 days. NuSTAR observations reveal that the source transitioned from a bright soft state with unabsorbed, bolometric (0.1\u2013100 keV) flux F = 6.9 \u00b1 0.1 \u00d7 10\u207b\u00b9\u2070 erg cm\u207b\u00b2 s\u207b\u00b9, to a low hard state with flux F = 2.85 \u00b1 0.04 \u00d7 10\u207b\u00b9\u2070 erg cm\u207b\u00b2 s\u207b\u00b9. Given a distance of 3.3 kpc, inferred via association of the source with the GLIMPSE-C01 cluster, these fluxes correspond to an Eddington fraction of the order of 10\u207b\u00b3 for an accreting neutron star (NS) of mass M = 1.4M\u2299, or even lower for a more massive accretor. However, the source spectra exhibit strong relativistic reflection features, indicating the presence of an accretion disk that extends close to the accretor, for which we measure a high spin, a = 0.967 \u00b1 0.013. In addition to a change in flux and spectral shape, we find evidence for other changes between the soft and hard states, including moderate disk truncation with the inner disk radius increasing from R_(in) \u2248 3 R_g to R_(in) \u2248 8 R_g, narrow Fe emission whose centroid decreases from 6.8 \u00b1 0.1 keV to 6.3 \u00b1 0.1 keV, and an increase in low-frequency (10\u207b\u00b3\u201310\u207b\u00b9 Hz) variability. Due to the high spin, we conclude that the source is likely to be a black hole rather than an NS, and we discuss physical interpretations of the low apparent luminosity as well as the narrow Fe emission.", "doi": "10.3847/1538-4357/ac5258", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2022-03-10", "series_number": "2", "volume": "927", "issue": "2", "pages": "Art. No. 190" }, { "id": "authors:3mzv9-ab577", "collection": "authors", "collection_id": "3mzv9-ab577", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220309-982137000", "type": "article", "title": "Radius Constraints from Reflection Modeling of Cygnus X-2 with NuSTAR and NICER", "author": [ { "family_name": "Ludlam", "given_name": "R. M.", "orcid": "0000-0002-8961-939X", "clpid": "Ludlam-Renee-M" }, { "family_name": "Cackett", "given_name": "E. M.", "orcid": "0000-0002-8294-9281", "clpid": "Cackett-Edward-M" }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Miller", "given_name": "J. M.", "clpid": "Miller-Jon-M" }, { "family_name": "Stevens", "given_name": "A. L.", "orcid": "0000-0002-5041-3079", "clpid": "Stevens-Abigail-L" }, { "family_name": "Fabian", "given_name": "A. C.", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-Andrew-C" }, { "family_name": "Homan", "given_name": "J.", "orcid": "0000-0001-8371-2713", "clpid": "Homan-Jeroen" }, { "family_name": "Ng", "given_name": "M.", "orcid": "0000-0002-0940-6563", "clpid": "Ng-Mason" }, { "family_name": "Guillot", "given_name": "S.", "orcid": "0000-0002-6449-106X", "clpid": "Guillot-Sebastien" }, { "family_name": "Buisson", "given_name": "D. J. K.", "clpid": "Buisson-Douglas-J-K" }, { "family_name": "Chakrabarty", "given_name": "D.", "orcid": "0000-0001-8804-8946", "clpid": "Chakrabarty-Deepto" } ], "abstract": "We present a spectral analysis of NuSTAR and NICER observations of the luminous, persistently accreting neutron star (NS) low-mass X-ray binary Cygnus X-2. The data were divided into different branches that the source traces out on the Z-track of the X-ray color\u2013color diagram; namely, the horizontal branch, the normal branch, and the vertex between the two. The X-ray continuum spectrum was modeled in two different ways that produced comparable quality fits. The spectra showed clear evidence of a reflection component in the form of a broadened Fe K line, as well as a lower-energy emission feature near 1 keV likely due to an ionized plasma located far from the innermost accretion disk. We account for the reflection spectrum with two independent models (relxillns and rdblur*rfxconv). The inferred inclination is in agreement with earlier estimates from optical observations of ellipsoidal lightcurve modeling (relxillns: i = 67\u00b0 \u00b1 4\u00b0; rdblur*rfxconv: i = 60\u00b0 \u00b1 10\u00b0). The inner disk radius remains close to the NS (R_(in) \u2264 1.15 R_(ISCO)) regardless of the source position along the Z-track or how the 1 keV feature is modeled. Given the optically determined NS mass of 1.71 \u00b1 0.21 M_\u2299, this corresponds to a conservative upper limit of R_(in) \u2264 19.5 km for M = 1.92 M_\u2299 or R_(in) \u2264 15.3 km for M = 1.5 M_\u2299. We compare these radius constraints to those obtained from NS gravitational wave merger events and recent NICER pulsar lightcurve modeling measurements.", "doi": "10.3847/1538-4357/ac5028", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2022-03-01", "series_number": "1", "volume": "927", "issue": "1", "pages": "Art. No. 112" }, { "id": "authors:tc42e-pwf35", "collection": "authors", "collection_id": "tc42e-pwf35", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220303-225982929", "type": "article", "title": "X-Ray Coronal Properties of Swift/BAT-selected Seyfert 1 Active Galactic Nuclei", "author": [ { "family_name": "Kamraj", "given_name": "Nikita", "orcid": "0000-0002-3233-2451", "clpid": "Kamraj-Nikita" }, { "family_name": "Brightman", "given_name": "Murray", "orcid": "0000-0002-8147-2602", "clpid": "Brightman-Murray" }, { "family_name": "Harrison", "given_name": "Fiona A.", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" }, { "family_name": "Stern", "given_name": "Daniel", "orcid": "0000-0003-2686-9241", "clpid": "Stern-Daniel" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Balokovi\u0107", "given_name": "Mislav", "orcid": "0000-0003-0476-6647", "clpid": "Balokovi\u0107-Mislav" }, { "family_name": "Ricci", "given_name": "Claudio", "orcid": "0000-0001-5231-2645", "clpid": "Ricci-Claudio" }, { "family_name": "Koss", "given_name": "Michael J.", "orcid": "0000-0002-7998-9581", "clpid": "Koss-Michael-J" }, { "family_name": "Mej\u00eda-Restrepo", "given_name": "Julian E.", "orcid": "0000-0001-8450-7463", "clpid": "Mej\u00eda-Restrepo-Julian-E" }, { "family_name": "Oh", "given_name": "Kyuseok", "orcid": "0000-0002-5037-951X", "clpid": "Oh-Kyuseok" }, { "family_name": "Powell", "given_name": "Meredith C.", "orcid": "0000-0003-2284-8603", "clpid": "Powell-Meredith-C" }, { "family_name": "Urry", "given_name": "C. Megan", "orcid": "0000-0002-0745-9792", "clpid": "Urry-C-Megan" } ], "abstract": "The corona is an integral component of active galactic nuclei (AGNs) which produces the bulk of the X-ray emission above 1\u20132 keV. However, many of its physical properties and the mechanisms powering this emission remain a mystery. In particular, the temperature of the coronal plasma has been difficult to constrain for large samples of AGNs, as constraints require high-quality broadband X-ray spectral coverage extending above 10 keV in order to measure the high-energy cutoff, which provides constraints on the combination of coronal optical depth and temperature. We present constraints on the coronal temperature for a large sample of Seyfert 1 AGNs selected from the Swift/BAT survey using high-quality hard X-ray data from the NuSTAR observatory combined with simultaneous soft X-ray data from Swift/XRT or XMM-Newton. When applying a physically motivated, nonrelativistic disk-reflection model to the X-ray spectra, we find a mean coronal temperature kT_e = 84 \u00b1 9 keV. We find no significant correlation between the coronal cutoff energy and accretion parameters such as the Eddington ratio and black hole mass. We also do not find a statistically significant correlation between the X-ray photon index, \u0393, and Eddington ratio. This calls into question the use of such relations to infer properties of supermassive black hole systems.", "doi": "10.3847/1538-4357/ac45f6", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2022-03-01", "series_number": "1", "volume": "927", "issue": "1", "pages": "Art. No. 42" }, { "id": "authors:m4x3e-91c36", "collection": "authors", "collection_id": "m4x3e-91c36", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220225-724712000", "type": "article", "title": "Extending the Baseline for SMC X-1's Spin and Orbital Behavior with NuSTAR Stray Light", "author": [ { "family_name": "Brumback", "given_name": "McKinley C.", "orcid": "0000-0002-4024-6967", "clpid": "Brumback-McKinley-C" }, { "family_name": "Grefenstette", "given_name": "Brian W.", "orcid": "0000-0002-1984-2932", "clpid": "Grefenstette-Brian-W" }, { "family_name": "Buisson", "given_name": "Douglas J. K.", "orcid": "0000-0002-5341-6929", "clpid": "Buisson-Douglas-J-K" }, { "family_name": "Bachetti", "given_name": "Matteo", "orcid": "0000-0002-4576-9337", "clpid": "Bachetti-Matteo" }, { "family_name": "Connors", "given_name": "Riley", "orcid": "0000-0002-8908-759X", "clpid": "Connors-Riley-M-T" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Jaodand", "given_name": "Amruta", "orcid": "0000-0002-3850-6651", "clpid": "Jaodand-Amruta-D" }, { "family_name": "Krivonos", "given_name": "Roman", "orcid": "0000-0003-2737-5673", "clpid": "Krivonos-Roman-A" }, { "family_name": "Ludlam", "given_name": "Renee", "orcid": "0000-0002-8961-939X", "clpid": "Ludlam-Renee-M" }, { "family_name": "Madsen", "given_name": "Kristin K.", "orcid": "0000-0003-1252-4891", "clpid": "Madsen-Kristin-K" }, { "family_name": "Mastroserio", "given_name": "Guglielmo", "orcid": "0000-0003-4216-7936", "clpid": "Mastroserio-Guglielmo" }, { "family_name": "Tomsick", "given_name": "John A.", "orcid": "0000-0001-5506-9855", "clpid": "Tomsick-John-A" }, { "family_name": "Wik", "given_name": "Daniel", "orcid": "0000-0001-9110-2245", "clpid": "Wik-Daniel" } ], "abstract": "StrayCats, the catalog of NuSTAR stray light observations, contains data from bright X-ray sources that fall within crowded source regions. These observations offer unique additional data with which to monitor sources such as X-ray binaries that show variable timing behavior. In this work, we present a timing analysis of stray light data of the high-mass X-ray binary SMC X-1, the first scientific analysis of a single source from the StrayCats project. We describe the process of screening stray light data for scientific analysis, verify the orbital ephemeris, and create both time- and energy-resolved pulse profiles. We find that the orbital ephemeris of SMC X-1 is unchanged and confirm a long-term spin-up rate of \u03bd \u0307 = (2.52 \u00b1 0.03) \u00d7 10\u207b\u00b9\u00b9 Hz s\u207b\u00b9. We also note that the shape of SMC X-1's pulse profile, while remaining double peaked, varies significantly with time and only slightly with energy.", "doi": "10.3847/1538-4357/ac4d24", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2022-02-20", "series_number": "2", "volume": "926", "issue": "2", "pages": "Art. No. 187" }, { "id": "authors:z7eth-f1r13", "collection": "authors", "collection_id": "z7eth-f1r13", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220113-182247899", "type": "article", "title": "Relativistic X-Ray Reflection Models for Accreting Neutron Stars", "author": [ { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-Thomas" }, { "family_name": "Ludlam", "given_name": "Renee", "orcid": "0000-0002-8961-939X", "clpid": "Ludlam-Renee-M" }, { "family_name": "Parker", "given_name": "Michael", "orcid": "0000-0002-8466-7317", "clpid": "Parker-Michael-L" }, { "family_name": "Fabian", "given_name": "Andrew", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-Andrew-C" }, { "family_name": "Harrison", "given_name": "Fiona A.", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" }, { "family_name": "Wilms", "given_name": "J\u00f6rn", "orcid": "0000-0003-2065-5410", "clpid": "Wilms-J\u00f6rn" } ], "abstract": "We present new reflection models specifically tailored to model the X-ray radiation reprocessed in accretion disks around neutron stars, in which the primary continuum is characterized by a single-temperature blackbody spectrum, emitted either at the surface of the star or at the boundary layer. These models differ significantly from those with a standard power-law continuum, typically observed in most accreting black holes. We show comparisons with earlier reflection models and test their performance in the NuSTAR observation of the neutron star 4U 1705\u221244. Simulations of upcoming missions such as XRISM-Resolve and Athena X-IFU are shown to highlight the diagnostic potential of these models for high-resolution X-ray reflection spectroscopy. These new reflection models xillverNS, and their relativistic counterpart relxillNS, are made publicly available to the community as an additional flavor in the relxill suite of reflection models.", "doi": "10.3847/1538-4357/ac3cb7", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2022-02-10", "series_number": "1", "volume": "926", "issue": "1", "pages": "Art. No. 13" }, { "id": "authors:43qph-n2y13", "collection": "authors", "collection_id": "43qph-n2y13", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220131-444344700", "type": "article", "title": "Plasma environment effects on K lines of astrophysical interest. V. Universal formulae for ionization potential and K-threshold shifts", "author": [ { "family_name": "Palmeri", "given_name": "P.", "orcid": "0000-0002-4372-6798", "clpid": "Palmeri-Patrick" }, { "family_name": "Deprince", "given_name": "J.", "orcid": "0000-0002-3409-8232", "clpid": "Deprince-J\u00e9r\u00f4me" }, { "family_name": "Bautista", "given_name": "M. A.", "orcid": "0000-0002-5522-9705", "clpid": "Bautista-Manuel-A" }, { "family_name": "Fritzsche", "given_name": "S.", "orcid": "0000-0003-3101-2824", "clpid": "Fritzsche-Stephan" }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Kallman", "given_name": "T. R.", "orcid": "0000-0002-5779-6906", "clpid": "Kallman-Timothy-R" }, { "family_name": "Mendoza", "given_name": "C.", "orcid": "0000-0002-2854-4806", "clpid": "Mendoza-Claudio" }, { "family_name": "Quinet", "given_name": "P.", "orcid": "0000-0002-3937-2640", "clpid": "Quinet-Pascal" } ], "abstract": "Aims. We calculate the plasma environment effects on the ionization potentials (IPs) and K-thresholds used in the modeling of K lines for all the ions belonging to the isonuclear sequences of abundant elements apart from oxygen and iron, namely: carbon, silicon, calcium, chromium, and nickel. These calculations are used to extend the data points for the fits of the universal formulae, first proposed in our fourth paper of this series, to predict the IP and K-threshold lowerings in any elemental ion. \n\nMethods. We used the fully relativistic multi-configuration Dirac\u2013Fock method and approximated the plasma electron-nucleus and electron-electron screenings with a time-averaged Debye\u2013H\u00fcckel potential. \n\nResults. We report the modified ionization potentials and K-threshold energies for plasmas characterized by electron temperatures and densities in the ranges of 10\u2075\u221210\u2077 K and 10\u00b9\u2078\u221210\u00b2\u00b2 cm\u207b\u00b3. In addition, the improved universal fitting formulae are obtained. \n\nConclusions. We conclude that since explicit calculations of the atomic structures for each ion of each element under different plasma conditions is impractical, the use of these universal formulae for predicting the IP and K-threshold lowerings in plasma modeling codes is still recommended. However, their comparatively moderate to low accuracies may affect the predicted opacities with regard to certain cases under extreme plasma conditions that are characterized by a plasma screening parameter of \u03bc > 0.2 a.u., especially for the K-thresholds.", "doi": "10.1051/0004-6361/202141550", "issn": "0004-6361", "publisher": "EDP Sciences", "publication": "Astronomy and Astrophysics", "publication_date": "2022-01", "volume": "657", "pages": "Art. No. A61" }, { "id": "authors:9dcsw-at394", "collection": "authors", "collection_id": "9dcsw-at394", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20211208-951173000", "type": "article", "title": "Spectral analysis of new black hole candidate AT2019wey observed by NuSTAR", "author": [ { "family_name": "Feng", "given_name": "Ye", "clpid": "Feng-Ye" }, { "family_name": "Zhao", "given_name": "XueShan", "clpid": "Zhao-Xueshan" }, { "family_name": "Gou", "given_name": "LiJun", "clpid": "Gou-Lijun" }, { "family_name": "Liu", "given_name": "YuFeng", "orcid": "0000-0002-1686-0545", "clpid": "Liu-Yufeng" }, { "family_name": "Steiner", "given_name": "James F.", "orcid": "0000-0002-5872-6061", "clpid": "Steiner-James-F" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Wang", "given_name": "Yuan", "clpid": "Wang-Yuan" }, { "family_name": "Jia", "given_name": "Nan", "clpid": "Jia-Nan" }, { "family_name": "Liao", "given_name": "ZhenXuan", "clpid": "Liao-ZhenXuan" }, { "family_name": "Li", "given_name": "HuiXian", "clpid": "Li-Huixian" } ], "abstract": "AT2019wey is a new galactic X-ray binary that was first discovered as an optical transient by the Australia Telescope Large Area Survey (ATLAS) on December 7, 2019. AT2019wey consists of a black hole candidate as well as a low-mass companion star (M_(star) \u2272 1.0 M_\u2299) and is likely to have a short orbital period (P_(orb) \u227216 h). Although AT2019wey began activation in the X-ray band during almost the entire outburst on March 8, 2020, it did not enter the soft state during the entire outburst. In this study, we present a detailed spectral analysis of AT2019wey in the low/hard state during its X-ray outburst on the basis of Nuclear Spectroscopic Telescope Array \\emph observations. We obtain tight constraints on several of its important physical parameters by applying the State-of-art \\texttt{relxill} relativistic reflection model family. In particular, we determine that the measured inner radius of the accretion disk is most likely to have extended to the innermost stable circular orbit (ISCO) radius, i.e., R_(in) = 1.38^(+0.23)_(\u22120.16) R_(ISCO). Hence, assuming R_(in) = R_(ISCO), we find the spin of AT2019wey to be a\u2217\u223c 0.97, which is close to the extreme and an inner disk inclination angle of ~i\u223c 22\u2218. Additionally, according to our adopted models, AT2019wey tends to have a relatively high iron abundance of A_(Fe)\u223c 5 A_(Fe,\u2299) and a high disk ionization state of log \u03be\u223c 3.4.", "doi": "10.1007/s11433-021-1790-7", "issn": "1674-7348", "publisher": "Springer Verlag", "publication": "Science China Physics, Mechanics and Astronomy", "publication_date": "2022-01", "series_number": "1", "volume": "65", "issue": "1", "pages": "Art. No. 219512" }, { "id": "authors:68m2c-8zk78", "collection": "authors", "collection_id": "68m2c-8zk78", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220107-873714900", "type": "article", "title": "On measuring the Hubble constant with X-ray reverberation mapping of active galactic nuclei", "author": [ { "family_name": "Ingram", "given_name": "Adam", "orcid": "0000-0002-5311-9078", "clpid": "Ingram-Adam" }, { "family_name": "Mastroserio", "given_name": "Guglielmo", "orcid": "0000-0003-4216-7936", "clpid": "Mastroserio-Guglielmo" }, { "family_name": "van\u00a0der\u00a0Klis", "given_name": "Michiel", "clpid": "van-der-Klis-Michiel" }, { "family_name": "Nathan", "given_name": "Edward", "orcid": "0000-0002-9633-9193", "clpid": "Nathan-Edward" }, { "family_name": "Connors", "given_name": "Riley", "orcid": "0000-0002-8908-759X", "clpid": "Connors-Riley-M-T" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-Thomas" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Kara", "given_name": "Erin", "orcid": "0000-0003-0172-0854", "clpid": "Kara-Erin" }, { "family_name": "K\u00f6nig", "given_name": "Ole", "clpid": "K\u00f6nig-Ole" }, { "family_name": "Lucchini", "given_name": "Matteo", "orcid": "0000-0002-2235-3347", "clpid": "Lucchini-Matteo" }, { "family_name": "Wang", "given_name": "Jingyi", "orcid": "0000-0002-1742-2125", "clpid": "Wang-Jingyi" } ], "abstract": "We show that X-ray reverberation mapping can be used to measure the distance to type 1 active galactic nuclei (AGNs). This is because X-ray photons originally emitted from the 'corona' close to the black hole irradiate the accretion disc and are reemitted with a characteristic 'reflection' spectrum that includes a prominent \u223c6.4 keV iron emission line. The shape of the reflection spectrum depends on the irradiating flux, and the light-crossing delay between continuum photons observed directly from the corona and the reflected photons constrain the size of the disc. Simultaneously modelling the X-ray spectrum and the time delays between photons of different energies therefore constrains the intrinsic reflected luminosity, and the distance follows from the observed reflected flux. Alternatively, the distance can be measured from the X-ray spectrum alone if the black hole mass is known. We develop a new model of our RELTRANS X-ray reverberation mapping package, called RTDIST, that has distance as a model parameter. We simulate a synthetic observation that we fit with our new model, and find that this technique applied to a sample of \u223c25 AGNs can be used to measure the Hubble constant with a 3\u03c3 statistical uncertainty of \u223c6km s\u207b\u00b9 Mpc\u207b\u00b9\u2060. Since the technique is completely independent of the traditional distance ladder and the cosmic microwave background radiation, it has the potential to address the current tension between them. We discuss sources of modelling uncertainty, and how they can be addressed in the near future.", "doi": "10.1093/mnras/stab2950", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2022-01", "series_number": "1", "volume": "509", "issue": "1", "pages": "619-633" }, { "id": "authors:7z51y-6z958", "collection": "authors", "collection_id": "7z51y-6z958", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20211123-234017978", "type": "article", "title": "Spectral and Timing Analysis of NuSTAR and Swift/XRT Observations of the X-Ray Transient MAXI J0637\u2013430", "author": [ { "family_name": "Lazar", "given_name": "Hadar", "orcid": "0000-0002-2752-9524", "clpid": "Lazar-Hadar" }, { "family_name": "Tomsick", "given_name": "John A.", "orcid": "0000-0001-5506-9855", "clpid": "Tomsick-John-A" }, { "family_name": "Pike", "given_name": "Sean N.", "orcid": "0000-0002-8403-0041", "clpid": "Pike-Sean-N" }, { "family_name": "Bachetti", "given_name": "Matteo", "orcid": "0000-0002-4576-9337", "clpid": "Bachetti-Matteo" }, { "family_name": "Buisson", "given_name": "Douglas J. K.", "clpid": "Hadar-Douglas-J-K" }, { "family_name": "Connors", "given_name": "Riley M. T.", "orcid": "0000-0002-8908-759X", "clpid": "Connors-Riley-M-T" }, { "family_name": "Fabian", "given_name": "Andrew C.", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-Andrew-C" }, { "family_name": "Fuerst", "given_name": "Felix", "orcid": "0000-0003-0388-0560", "clpid": "F\u00fcrst-Felix" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Hare", "given_name": "Jeremy", "orcid": "0000-0002-8548-482X", "clpid": "Hare-Jeremy" }, { "family_name": "Jiang", "given_name": "Jiachen", "orcid": "0000-0002-9639-4352", "clpid": "Jiang-Jiachen" }, { "family_name": "Shaw", "given_name": "Aarran W.", "orcid": "0000-0002-8808-520X", "clpid": "Shaw-Aarran-W" }, { "family_name": "Walton", "given_name": "Dominic J.", "orcid": "0000-0001-5819-3552", "clpid": "Walton-Dominic-J" } ], "abstract": "We present results for the first observed outburst from the transient X-ray binary source MAXI J0637\u2013430. This study is based on eight observations from the Nuclear Spectroscopic Telescope Array (NuSTAR) and six observations from the Neil Gehrels Swift Observatory X-Ray Telescope (Swift/XRT) collected from 2019 November 19 to 2020 April 26 as the 3\u201379 keV source flux declined from 8.2 \u00d7 10\u207b\u00b9\u2070 to 1.4 \u00d7 10\u207b\u00b9\u00b2 erg cm\u207b\u00b2 s\u207b\u00b9. We see the source transition from a soft state with a strong disk-blackbody component to a hard state dominated by a power-law or thermal Comptonization component. NuSTAR provides the first reported coverage of MAXI J0637\u2013430 above 10 keV, and these broadband spectra show that a two-component model does not provide an adequate description of the soft-state spectrum. As such, we test whether blackbody emission from the plunging region could explain the excess emission. As an alternative, we test a reflection model that includes a physical Comptonization continuum. Finally, we also test a spectral component based on reflection of a blackbody illumination spectrum, which can be interpreted as a simple approximation to the reflection produced by returning disk radiation due to the bending of light by the strong gravity of the black hole. We discuss the physical implications of each scenario and demonstrate the value of constraining the source distance.", "doi": "10.3847/1538-4357/ac1bab", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2021-11-10", "series_number": "2", "volume": "921", "issue": "2", "pages": "Art. No. 155" }, { "id": "authors:nh2bc-r2h95", "collection": "authors", "collection_id": "nh2bc-r2h95", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210106-131324406", "type": "article", "title": "A Comprehensive X-Ray Report on AT2019wey", "author": [ { "family_name": "Yao", "given_name": "Yuhan", "orcid": "0000-0001-6747-8509", "clpid": "Yao-Yuhan" }, { "family_name": "Kulkarni", "given_name": "S. R.", "orcid": "0000-0001-5390-8563", "clpid": "Kulkarni-S-R" }, { "family_name": "Gendreau", "given_name": "K. C.", "orcid": "0000-0001-7115-2819", "clpid": "Gendreau-Keith-C" }, { "family_name": "Jaisawal", "given_name": "Gaurava K.", "orcid": "0000-0002-6789-2723", "clpid": "Jaisawal-Gaurava-K" }, { "family_name": "Enoto", "given_name": "Teruaki", "orcid": "0000-0003-1244-3100", "clpid": "Enoto-Teruaki" }, { "family_name": "Grefenstette", "given_name": "Brian W.", "orcid": "0000-0002-1984-2932", "clpid": "Grefenstette-Brian-W" }, { "family_name": "Marshall", "given_name": "Herman L.", "orcid": "0000-0002-6492-1293", "clpid": "Marshall-Herman-L" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Ludlam", "given_name": "R. M.", "orcid": "0000-0002-8961-939X", "clpid": "Ludlam-Renee-M" }, { "family_name": "Pike", "given_name": "Sean N.", "orcid": "0000-0002-8403-0041", "clpid": "Pike-Sean-N" }, { "family_name": "Ng", "given_name": "Mason", "orcid": "0000-0002-0940-6563", "clpid": "Ng-Mason" }, { "family_name": "Zhang", "given_name": "Liang", "orcid": "0000-0003-4498-9925", "clpid": "Zhang-Liang-ASTROPHYSICS" }, { "family_name": "Altamirano", "given_name": "Diego", "orcid": "0000-0002-3422-0074", "clpid": "Altamirano-Diego" }, { "family_name": "Jaodand", "given_name": "Amruta", "orcid": "0000-0002-3850-6651", "clpid": "Jaodand-Amruta-D" }, { "family_name": "Cenko", "given_name": "S. Bradley", "orcid": "0000-0003-1673-970X", "clpid": "Cenko-S-Bradley" }, { "family_name": "Remillard", "given_name": "Ronald A.", "orcid": "0000-0003-4815-0481", "clpid": "Remillard-Ronald-A" }, { "family_name": "Steiner", "given_name": "James F.", "orcid": "0000-0002-5872-6061", "clpid": "Steiner-James-F" }, { "family_name": "Negoro", "given_name": "Hitoshi", "orcid": "0000-0003-0939-1178", "clpid": "Negoro-Hitoshi" }, { "family_name": "Brightman", "given_name": "Murray", "orcid": "0000-0002-8147-2602", "clpid": "Brightman-Murray" }, { "family_name": "Lien", "given_name": "Amy", "orcid": "0000-0002-7851-9756", "clpid": "Lien-Amy" }, { "family_name": "Wolff", "given_name": "Michael T.", "orcid": "0000-0002-4013-5650", "clpid": "Wolff-Michael-T" }, { "family_name": "Ray", "given_name": "Paul S.", "orcid": "0000-0002-5297-5278", "clpid": "Ray-Paul-S" }, { "family_name": "Mukai", "given_name": "Koji", "clpid": "Mukai-Koji" }, { "family_name": "Wadiasingh", "given_name": "Zorawar", "orcid": "0000-0002-9249-0515", "clpid": "Wadiasingh-Zorawar" }, { "family_name": "Arzoumanian", "given_name": "Zaven", "clpid": "Arzoumanian-Zaven" }, { "family_name": "Kawai", "given_name": "Nobuyki", "orcid": "0000-0001-9656-0261", "clpid": "Kawai-Nobuyki" }, { "family_name": "Mihara", "given_name": "Tatehiro", "orcid": "0000-0002-6337-7943", "clpid": "Mihara-Tatehiro" }, { "family_name": "Strohmayer", "given_name": "Tod E.", "orcid": "0000-0001-7681-5845", "clpid": "Strohmayer-Tod-E" } ], "abstract": "Here, we present MAXI, Swift, NICER, NuSTAR, and Chandra observations of the X-ray transient AT2019wey (SRGA J043520.9+552226, SRGE J043523.3+552234). From spectral and timing analyses we classify it as a Galactic low-mass X-ray binary (LMXB) with a black hole (BH) or neutron star (NS) accretor. AT2019wey stayed in the low/hard state (LHS) from 2019 December to 2020 August 21, and the hard-intermediate state (HIMS) from 2020 August 21 to 2020 November. For the first six months of the LHS, AT2019wey had a flux of \u223c1 mCrab, and displayed a power-law X-ray spectrum with photon index \u0393 = 1.8. From 2020 June to August, it brightened to \u223c20 mCrab. Spectral features characteristic of relativistic reflection became prominent. On 2020 August 21, the source left the \"hard line\" on the rms\u2013intensity diagram, and transitioned from LHS to HIMS. The thermal disk component became comparable to the power-law component. A low-frequency quasi-periodic oscillation (QPO) was observed. The QPO central frequency increased as the spectrum softened. No evidence of pulsation was detected. We are not able to decisively determine the nature of the accretor (BH or NS). However, the BH option is favored by the position of this source on the \u0393\u2013L_X, L_(radio)\u2013L_X, and L_(opt)\u2013L_X diagrams. We find the BH candidate XTE J1752\u2212223 to be an analog of AT2019wey. Both systems display outbursts with long plateau phases in the hard states. We conclude by noting the potential of SRG in finding new members of this emerging class of low luminosity and long-duration LMXB outbursts.", "doi": "10.3847/1538-4357/ac15f8", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2021-10-20", "series_number": "2", "volume": "920", "issue": "2", "pages": "Art. No. 121" }, { "id": "authors:jvp1g-21v48", "collection": "authors", "collection_id": "jvp1g-21v48", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20211020-164833304", "type": "article", "title": "Modelling correlated variability in accreting black holes: the effect of high density and variable ionization on reverberation lags", "author": [ { "family_name": "Mastroserio", "given_name": "Guglielmo", "orcid": "0000-0003-4216-7936", "clpid": "Mastroserio-Guglielmo" }, { "family_name": "Ingram", "given_name": "Adam", "orcid": "0000-0002-5311-9078", "clpid": "Ingram-Adam" }, { "family_name": "Wang", "given_name": "Jingyi", "orcid": "0000-0002-1742-2125", "clpid": "Wang-Jingyi" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "van der Klis", "given_name": "Michiel", "orcid": "0000-0003-0070-9872", "clpid": "van-der-Klis-Michiel" }, { "family_name": "Cavecchi", "given_name": "Yuri", "orcid": "0000-0002-6447-3603", "clpid": "Cavecchi-Yuri" }, { "family_name": "Connors", "given_name": "Riley", "orcid": "0000-0002-8908-759X", "clpid": "Connors-Riley-M-T" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-Thomas" }, { "family_name": "Harrison", "given_name": "Fiona", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" }, { "family_name": "Kara", "given_name": "Erin", "orcid": "0000-0003-0172-0854", "clpid": "Kara-Erin" }, { "family_name": "K\u00f6nig", "given_name": "Ole", "clpid": "K\u00f6nig-Ole" }, { "family_name": "Lucchini", "given_name": "Matteo", "orcid": "0000-0002-2235-3347", "clpid": "Lucchini-Matteo" } ], "abstract": "We present a new release of the RELTRANS model to fit the complex cross-spectrum of accreting black holes as a function of energy. The model accounts for continuum lags and reverberation lags self-consistently in order to consider the widest possible range of X-ray variability time-scales. We introduce a more self-consistent treatment of the reverberation lags, accounting for how the time variations of the illuminating flux change the ionization level of the accretion disc. This process varies the shape of the reflection spectrum in time causing an additional source of lags besides the light crossing delay. We also consider electron densities in the accretion disc up to 10\u00b2\u2070\u2009cm\u207b\u00b3, which are found in most of the stellar mass black holes and in some active galactic nuclei. These high densities increase the amplitude of the reverberation lags below 1 keV since the reflection flux enhances in the same energy range. In addition, we investigate the properties of hard lags produced by variations in the power-law index of the continuum spectrum, which can be interpreted as due to roughly 3 per cent3 per cent variability in the corona's optical depth and temperature. As a test case, we simultaneously fit the lag-energy spectra in a wide range of Fourier frequency for the black hole candidate MAXI J1820+0701820 observed with NICER. The best fit shows how the reverberation lags contribute even at the longer time-scales where the hard lags are important. This proves the importance of modelling these two lags together and self-consistently in order to constrain the parameters of the system.", "doi": "10.1093/mnras/stab2056", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2021-10", "series_number": "1", "volume": "507", "issue": "1", "pages": "55-73" }, { "id": "authors:zdnsf-ajx86", "collection": "authors", "collection_id": "zdnsf-ajx86", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210914-225403760", "type": "article", "title": "Photospheric Radius Expansion and a Double-peaked Type-I X-Ray Burst from GRS 1741.9\u20132853", "author": [ { "family_name": "Pike", "given_name": "Sean N.", "orcid": "0000-0002-8403-0041", "clpid": "Pike-Sean-N" }, { "family_name": "Harrison", "given_name": "Fiona A.", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" }, { "family_name": "Tomsick", "given_name": "John A.", "orcid": "0000-0001-5506-9855", "clpid": "Tomsick-John-A" }, { "family_name": "Bachetti", "given_name": "Matteo", "orcid": "0000-0002-4576-9337", "clpid": "Bachetti-Matteo" }, { "family_name": "Buisson", "given_name": "Douglas J. K.", "clpid": "Buisson-Douglas-J-K" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Jiang", "given_name": "Jiachen", "orcid": "0000-0002-9639-4352", "clpid": "Jiang-Jiachen" }, { "family_name": "Ludlam", "given_name": "R. M.", "orcid": "0000-0002-8961-939X", "clpid": "Ludlam-Renee-M" }, { "family_name": "Madsen", "given_name": "Kristin K.", "orcid": "0000-0003-1252-4891", "clpid": "Madsen-Kristin-K" } ], "abstract": "We present an analysis of two type-I X-ray bursts observed by NuSTAR originating from the very faint transient neutron star (NS) low-mass X-ray binary GRS 1741.9\u20132853 during a period of outburst in 2020 May. We show that the persistent emission can be modeled as an absorbed, Comptonized blackbody in addition to Fe K\u03b1 emission, which can be attributed to relativistic disk reflection. We measure a persistent bolometric, unabsorbed luminosity of L_(bol) = 7.03_(-0.05)^(+0.04) x 10\u00b3\u2076 erg s\u207b\u00b9, assuming a distance of 7 kpc, corresponding to an Eddington ratio of 4.5%. This persistent luminosity combined with light-curve analysis leads us to infer that the bursts were the result of pure He burning rather than mixed H/He burning. Time-resolved spectroscopy reveals that the bolometric flux of the first burst exhibits a double-peaked structure, placing the source within a small population of accreting NSs that exhibit multiple-peaked type-I X-ray bursts. We find that the second, brighter burst shows evidence for photospheric radius expansion (PRE) and that at its peak, this PRE event had an unabsorbed bolometric flux of F_(peak) = 2.94_(-0.26)^(+0.28) x 10\u207b\u2078 erg cm\u207b\u00b2 s\u207b\u00b9. This yields a new distance estimate of d = 9.0 \u00b1 0.5 kpc, assuming that this corresponds to the Eddington limit for pure He burning on the surface of a canonical NS. Additionally, we performed a detailed timing analysis that failed to find evidence for quasi-periodic oscillations or burst oscillations, and we place an upper limit of 16% on the rms variability around 589 Hz, the frequency at which oscillations have previously been reported.", "doi": "10.3847/1538-4357/ac0ef9", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2021-09-01", "series_number": "1", "volume": "918", "issue": "1", "pages": "Art. No. 9" }, { "id": "authors:s29tw-5ty76", "collection": "authors", "collection_id": "s29tw-5ty76", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20211011-221326133", "type": "article", "title": "Extreme relativistic reflection in the active galaxy ESO\u2009033-G002", "author": [ { "family_name": "Walton", "given_name": "D. J.", "orcid": "0000-0001-5819-3552", "clpid": "Walton-Dominic-J" }, { "family_name": "Balokovi\u0107", "given_name": "M.", "orcid": "0000-0003-0476-6647", "clpid": "Balokovi\u0107-Mislav" }, { "family_name": "Fabian", "given_name": "A. C.", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-Andrew-C" }, { "family_name": "Gallo", "given_name": "L. C.", "clpid": "Gallo-Luigi-C-C" }, { "family_name": "Koss", "given_name": "M.", "orcid": "0000-0002-7998-9581", "clpid": "Koss-Michael-J" }, { "family_name": "Nardini", "given_name": "E.", "orcid": "0000-0001-9226-8992", "clpid": "Nardini-Emanuele" }, { "family_name": "Reynolds", "given_name": "C. S.", "orcid": "0000-0002-1510-4860", "clpid": "Reynolds-Christopher-S" }, { "family_name": "Ricci", "given_name": "C.", "orcid": "0000-0001-5231-2645", "clpid": "Ricci-Claudio" }, { "family_name": "Stern", "given_name": "D.", "orcid": "0000-0003-2686-9241", "clpid": "Stern-Daniel" }, { "family_name": "Alston", "given_name": "W. N.", "orcid": "0000-0003-2658-6559", "clpid": "Alston-William-N" }, { "family_name": "Dauser", "given_name": "T.", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-Thomas" }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Kosec", "given_name": "P.", "clpid": "Kosec-P" }, { "family_name": "Reynolds", "given_name": "M. T.", "orcid": "0000-0003-1621-9392", "clpid": "Reynolds-Mark-T" }, { "family_name": "Harrison", "given_name": "F. A.", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" }, { "family_name": "Miller", "given_name": "J. M.", "clpid": "Miller-Jon-M" } ], "abstract": "We present the first high signal-to-noise broad-band X-ray spectrum of the radio-quiet type-2 Seyfert ESO\u2009033-G002, combining data from XMM\u2013Newton and NuSTAR. The nuclear X-ray spectrum is complex, showing evidence for both neutral and ionized absorption, as well as reflection from both the accretion disc and more distant material, but our broad-band coverage allows us to disentangle all of these different components. The total neutral column during this epoch is N_H \u223c (5\u22126) \u00d7 10\u00b2\u00b2\u2009cm\u207b\u00b2\u2060, consistent with the optical classification of ESO\u2009033-G002 as a type-2 Seyfert but not so large as to prevent us from robustly determining the properties of the innermost accretion flow. The ionized absorption \u2013 dominated by lines from Fe\u2009XXV and Fe\u2009XXVI \u2013 reveals a moderately rapid outflow (v_(out) \u223c 5400\u2009km s\u207b\u00b9) which has a column comparable to the neutral absorption. We find the disc reflection from the innermost regions to be extreme, with a reflection fraction of R_(frac) \u223c 5. This requires strong gravitational lightbending and, in turn, both an extremely compact corona (within \u223c2\u2009R_G of the black hole) and a rapidly rotating black hole (a* > 0.96). Despite this tight size constraint, with a temperature of kT_e = 40\u201370\u2009keV the X-ray corona in ESO\u2009033-G002 appears similar to other active galactic nucle in terms of its placement in the compactness\u2013temperature plane, consistent with sitting close to the limit determined by runaway pair production. Finally, combining X-ray spectroscopy, timing, and updated optical spectroscopy, we also estimate the mass of the black hole to be log[M_(BH)/M_\u2299] \u223c 7.0\u20137.5.", "doi": "10.1093/mnras/stab1290", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2021-09", "series_number": "2", "volume": "506", "issue": "2", "pages": "1557-1572" }, { "id": "authors:4kssb-d9911", "collection": "authors", "collection_id": "4kssb-d9911", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210729-205241904", "type": "article", "title": "Towards Precision Measurements of Accreting Black Holes Using X-Ray Reflection Spectroscopy", "author": [ { "family_name": "Bambi", "given_name": "Cosimo", "orcid": "0000-0002-3180-9502", "clpid": "Bambi-Cosimo" }, { "family_name": "Brenneman", "given_name": "Laura W.", "clpid": "Brenneman-Laura-W" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-Thomas" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Grinberg", "given_name": "Victoria", "orcid": "0000-0003-2538-0188", "clpid": "Grinberg-Victoria" }, { "family_name": "Ingram", "given_name": "Adam", "orcid": "0000-0002-5311-9078", "clpid": "Ingram-Adam" }, { "family_name": "Jiang", "given_name": "Jiachen", "orcid": "0000-0002-9639-4352", "clpid": "Jiang-Jiachen" }, { "family_name": "Liu", "given_name": "Honghui", "orcid": "0000-0003-2845-1009", "clpid": "Liu-Honghui" }, { "family_name": "Lohfink", "given_name": "Anne M.", "clpid": "Lohfink-Anne-M" }, { "family_name": "Marinucci", "given_name": "Andrea", "clpid": "Marinucci-Andrea" }, { "family_name": "Mastroserio", "given_name": "Guglielmo", "orcid": "0000-0003-4216-7936", "clpid": "Mastroserio-Guglielmo" }, { "family_name": "Middei", "given_name": "Riccardo", "orcid": "0000-0001-9815-9092", "clpid": "Middei-Riccardo" }, { "family_name": "Nampalliwar", "given_name": "Sourabh", "orcid": "0000-0002-9608-1102", "clpid": "Nampalliwar-Sourabh" }, { "family_name": "Nied\u017awiecki", "given_name": "Andrzej", "clpid": "Nied\u017awiecki-Andrzej" }, { "family_name": "Steiner", "given_name": "James F.", "orcid": "0000-0002-5872-6061", "clpid": "Steiner-James-F" }, { "family_name": "Tripathi", "given_name": "Ashutosh", "orcid": "0000-0002-3960-5870", "clpid": "Tripathi-Ashutosh" }, { "family_name": "Zdziarski", "given_name": "Andrzej A.", "clpid": "Zdziarski-Andrzej-A" } ], "abstract": "Relativistic reflection features are commonly observed in the X-ray spectra of accreting black holes. In the presence of high quality data and with the correct astrophysical model, X-ray reflection spectroscopy can be quite a powerful tool to probe the strong gravity region, study the morphology of the accreting matter, measure black hole spins, and possibly test Einstein's theory of general relativity in the strong field regime. In the last decade, there has been significant progress in the development of the analysis of these features, thanks to more sophisticated astrophysical models and new observational facilities. Here we review the state-of-the-art in relativistic reflection modeling, listing assumptions and simplifications that may affect, at some level, the final measurements and may be investigated better in the future. We review black hole spin measurements and the most recent efforts to use X-ray reflection spectroscopy for testing fundamental physics.", "doi": "10.1007/s11214-021-00841-8", "issn": "0038-6308", "publisher": "Springer", "publication": "Space Science Reviews", "publication_date": "2021-08", "series_number": "5", "volume": "217", "issue": "5", "pages": "Art. No. 65" }, { "id": "authors:kyqwj-9y619", "collection": "authors", "collection_id": "kyqwj-9y619", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210720-195758956", "type": "article", "title": "X-ray emission from magnetized neutron star atmospheres at low mass-accretion rates. I. Phase-averaged spectrum", "author": [ { "family_name": "Sokolova-Lapa", "given_name": "E.", "orcid": "0000-0001-7948-0470", "clpid": "Sokolova-Lapa-Ekaterina" }, { "family_name": "Gornostaev", "given_name": "M.", "clpid": "Gornostaev-Mikhail" }, { "family_name": "Wilms", "given_name": "J.", "orcid": "0000-0003-2065-5410", "clpid": "Wilms-J\u00f6rn" }, { "family_name": "Ballhausen", "given_name": "R.", "orcid": "0000-0002-1118-8470", "clpid": "Ballhausen-Ralf" }, { "family_name": "Falkner", "given_name": "S.", "orcid": "0000-0001-5209-991X", "clpid": "Falkner-Sebastian" }, { "family_name": "Postnov", "given_name": "K.", "orcid": "0000-0002-1705-617X", "clpid": "Postnov-Konstantin" }, { "family_name": "Thalhammer", "given_name": "P.", "clpid": "Thalhammer-P" }, { "family_name": "F\u00fcrst", "given_name": "F.", "orcid": "0000-0003-0388-0560", "clpid": "F\u00fcrst-Felix" }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Shakura", "given_name": "N.", "orcid": "0000-0002-5672-9517", "clpid": "Shakura-Nikolay" }, { "family_name": "Becker", "given_name": "P. A.", "orcid": "0000-0002-3718-1293", "clpid": "Becker-Peter-A" }, { "family_name": "Wolff", "given_name": "M. T.", "orcid": "0000-0002-4013-5650", "clpid": "Wolff-Michael-T" }, { "family_name": "Pottschmidt", "given_name": "K.", "orcid": "0000-0002-4656-6881", "clpid": "Pottschmidt-Katja" }, { "family_name": "H\u00e4rer", "given_name": "L.", "orcid": "0000-0002-5377-0493", "clpid": "H\u00e4rer-Lucia" }, { "family_name": "Malacaria", "given_name": "C.", "orcid": "0000-0002-0380-0041", "clpid": "Malacaria-Christian" } ], "abstract": "Recent observations of X-ray pulsars at low luminosities allow, for the first time, the comparison of theoretical models of the emission from highly magnetized neutron star atmospheres at low mass-accretion rates (\u1e40 \u2272 10\u00b9\u2075 g s\u207b\u00b9) with the broadband X-ray data. The purpose of this paper is to investigate spectral formation in the neutron star atmosphere at low \u1e40 and to conduct a parameter study of the physical properties of the emitting region. We obtain the structure of the static atmosphere, assuming that Coulomb collisions are the dominant deceleration process. The upper part of the atmosphere is strongly heated by the braking plasma, reaching temperatures of 30\u201340 keV, while its denser isothermal interior is much cooler (\u223c2 keV). We numerically solve the polarized radiative transfer in the atmosphere with magnetic Compton scattering, free\u2013free processes, and nonthermal cyclotron emission due to possible collisional excitations of electrons. The strongly polarized emitted spectrum has a double-hump shape that is observed in low-luminosity X-ray pulsars. A low-energy \"thermal\" component is dominated by extraordinary photons that can leave the atmosphere from deeper layers because of their long mean free path at soft energies. We find that a high-energy component is formed because of resonant Comptonization in the heated nonisothermal part of the atmosphere even in the absence of collisional excitations. However, these latter, if present, affect the ratio of the two components. A strong cyclotron line originates from the optically thin, uppermost zone. A fit of the model to NuSTAR and Swift/XRT observations of GX 304\u22121 provides an accurate description of the data with reasonable parameters. The model can thus reproduce the characteristic double-hump spectrum observed in low-luminosity X-ray pulsars and provides insights into spectral formation.", "doi": "10.1051/0004-6361/202040228", "issn": "0004-6361", "publisher": "EDP Sciences", "publication": "Astronomy and Astrophysics", "publication_date": "2021-07", "volume": "651", "pages": "Art. No. A12" }, { "id": "authors:6ydmw-fsk71", "collection": "authors", "collection_id": "6ydmw-fsk71", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210626-222733320", "type": "article", "title": "Nitrogen X-ray absorption in the local ISM", "author": [ { "family_name": "Gatuzz", "given_name": "Efra\u00edn", "orcid": "0000-0002-3252-9633", "clpid": "Gatuzz-Efrain" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Kallman", "given_name": "Timothy R.", "orcid": "0000-0002-5779-6906", "clpid": "Kallman-Timothy-R" } ], "abstract": "Nitrogen is one of the most abundant metals in the interstellar medium (ISM), and thus it constitutes an excellent test to study a variety of astrophysical environments, ranging from nova to active galactic nuclei. We present a detailed analysis of the gaseous component of the N K-edge using high-resolution XMM\u2013Newton spectra of 12 Galactic and 40 extragalactic sources. For each source, we have estimated column densities for N I, N II, N III, N V, N VI, and N VII ionic species, which trace the cold, warm, and hot phases of the local Galactic ISM. We have found that the cold-warm component column densities decrease with the Galactic latitude, while the hot component does not. Moreover, the cold column density distribution is in good agreement with UV measurements. This is the first detailed analysis of the nitrogen K-edge absorption due to ISM using high-resolution X-ray spectra.", "doi": "10.1093/mnras/stab1185", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2021-07", "series_number": "3", "volume": "504", "issue": "3", "pages": "4460-4471" }, { "id": "authors:hgbcm-bsv10", "collection": "authors", "collection_id": "hgbcm-bsv10", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210519-141321220", "type": "article", "title": "The Nature of Soft Excess in ESO 362-G18 Revealed by XMM-Newton and NuSTAR Spectroscopy", "author": [ { "family_name": "Xu", "given_name": "Yerong", "orcid": "0000-0002-2523-5485", "clpid": "Xu-Yerong" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Walton", "given_name": "Dominic J.", "orcid": "0000-0001-5819-3552", "clpid": "Walton-Dominic-J" }, { "family_name": "Connors", "given_name": "Riley M. T.", "orcid": "0000-0002-8908-759X", "clpid": "Connors-Riley-M-T" }, { "family_name": "Madsen", "given_name": "Kristin", "orcid": "0000-0003-1252-4891", "clpid": "Madsen-Kristin-K" }, { "family_name": "Harrison", "given_name": "Fiona A.", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" } ], "abstract": "We present a detailed spectral analysis of the joint XMM-Newton and NuSTAR observations of the active galactic nuclei (AGNs) in the Seyfert 1.5 Galaxy ESO 362-G18. The broadband (0.3\u201379 keV) spectrum shows the presence of a power-law continuum with a soft excess below 2 keV, iron K\u03b1 emission (~6.4 keV), and a Compton hump (peaking at ~20 keV). We find that the soft excess can be modeled by two different possible scenarios: a warm (kT_e ~ 0.2 keV) and optically thick (\u03c4 ~ 34) Comptonizing corona, or with a relativistically blurred reflection off a high-density (log [n_e/cm\u207b\u00b3 > 18.3) inner disk. These two models cannot be easily distinguished solely from their fit statistics. However, the low temperature (kT_e ~ 20 keV) and the thick optical depth (\u03c4 ~ 5) of the hot corona required by the warm corona scenario are uncommon for AGNs. We also fit a \"hybrid\" model, which includes both disk reflection and a warm corona. Unsurprisingly, as this is the most complex of the models considered, this provides the best fit, and more reasonable coronal parameters. In this case, the majority of the soft excess flux arises in the warm corona component. However, based on recent simulations of warm coronae, it is not clear whether such a structure can really exist at the low accretion rates relevant for ESO 362-G18 (\u1e41 ~ 0.015). This may therefore argue in favor of a scenario in which the soft excess is instead dominated by the relativistic reflection. Based on this model, we find that the data would require a compact hot corona (h ~ 3 R_(Horizon)) around a rapidly spinning (a_\u2605 > 0.927) black hole.", "doi": "10.3847/1538-4357/abf430", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2021-05-20", "series_number": "1", "volume": "913", "issue": "1", "pages": "Art. No. 13" }, { "id": "authors:a0pfa-9y081", "collection": "authors", "collection_id": "a0pfa-9y081", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210429-144554967", "type": "article", "title": "Simultaneous NICER and NuSTAR Observations of the Ultracompact X-Ray Binary 4U 1543\u2013624", "author": [ { "family_name": "Ludlam", "given_name": "R. M.", "orcid": "0000-0002-8961-939X", "clpid": "Ludlam-Renee-M" }, { "family_name": "Jaodand", "given_name": "A. D.", "orcid": "0000-0002-3850-6651", "clpid": "Jaodand-Amruta-D" }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Degenaar", "given_name": "N.", "clpid": "Degenaar-N" }, { "family_name": "Tomsick", "given_name": "J. A.", "orcid": "0000-0001-5506-9855", "clpid": "Tomsick-John-A" }, { "family_name": "Cackett", "given_name": "E. M.", "orcid": "0000-0002-8294-9281", "clpid": "Cackett-Edward-M" }, { "family_name": "Fabian", "given_name": "A. C.", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-Andrew-C" }, { "family_name": "Gandhi", "given_name": "P.", "orcid": "0000-0003-3105-2615", "clpid": "Gandhi-Poshak" }, { "family_name": "Buisson", "given_name": "D. J. K.", "clpid": "Buisson-Douglas-J-K" }, { "family_name": "Shaw", "given_name": "A. W.", "orcid": "0000-0002-8808-520X", "clpid": "Shaw-Aarran-W" }, { "family_name": "Chakrabarty", "given_name": "D.", "orcid": "0000-0001-8804-8946", "clpid": "Chakrabarty-Deepto" } ], "abstract": "We present the first joint NuSTAR and NICER observations of the ultracompact X-ray binary (UCXB) 4U 1543\u2212624 obtained in 2020 April. The source was at a luminosity of L_(0.5\u221250 keV) = 4.9(D/7 kpc)\u00b2 \u00d7 1036 erg s\u207b\u00b9 and showed evidence of reflected emission in the form of an O viii line, Fe K line, and Compton hump within the spectrum. We used a full reflection model, known as xillverCO, that is tailored for the atypical abundances found in UCXBs, to account for the reflected emission. We tested the emission radii of the O and Fe line components and conclude that they originate from a common disk radius in the innermost region of the accretion disk (R_(in) \u2264 1.07 R_(ISCO)). Assuming that the compact accretor is a neutron star (NS) and the position of the inner disk is the Alfv\u00e9n radius, we placed an upper limit on the magnetic field strength to be B \u2264 0.7(D/7 kpc) \u00d7 10\u2078 G at the poles. Given the lack of pulsations detected and position of R_(in), it was likely that a boundary layer region had formed between the NS surface and inner edge of the accretion disk with an extent of 1.2 km. This implies a maximum radius of the neutron star accretor of R_(NS) \u2264 12.1 km when assuming a canonical NS mass of 1.4 M_\u2299.", "doi": "10.3847/1538-4357/abedb0", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2021-04-20", "series_number": "2", "volume": "911", "issue": "2", "pages": "Art. No. 123" }, { "id": "authors:x4bgk-0fm60", "collection": "authors", "collection_id": "x4bgk-0fm60", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210401-100722072", "type": "article", "title": "Disk, Corona, Jet Connection in the Intermediate State of MAXI J1820+070 Revealed by NICER Spectral-timing Analysis", "author": [ { "family_name": "Wang", "given_name": "Jingyi", "orcid": "0000-0002-1742-2125", "clpid": "Wang-Jingyi" }, { "family_name": "Mastroserio", "given_name": "Guglielmo", "orcid": "0000-0003-4216-7936", "clpid": "Mastroserio-Guglielmo" }, { "family_name": "Kara", "given_name": "Erin", "orcid": "0000-0003-0172-0854", "clpid": "Kara-Erin" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Ingram", "given_name": "Adam", "orcid": "0000-0002-5311-9078", "clpid": "Ingram-Adam" }, { "family_name": "Connors", "given_name": "Riley", "orcid": "0000-0002-8908-759X", "clpid": "Connors-R-M-T" }, { "family_name": "van der Klis", "given_name": "Michiel", "orcid": "0000-0003-0070-9872", "clpid": "van-der-Klis-Michiel" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-Thomas" }, { "family_name": "Steiner", "given_name": "James F.", "orcid": "0000-0002-5872-6061", "clpid": "Steiner-James-F" }, { "family_name": "Buisson", "given_name": "Douglas J. K.", "clpid": "Buisson-Douglas-J-K" }, { "family_name": "Homan", "given_name": "Jeroen", "orcid": "0000-0001-8371-2713", "clpid": "Homan-Jeroen" }, { "family_name": "Lucchini", "given_name": "Matteo", "orcid": "0000-0002-2235-3347", "clpid": "Lucchini-Matteo" }, { "family_name": "Fabian", "given_name": "Andrew C.", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-Andrew-C" }, { "family_name": "Bright", "given_name": "Joe", "orcid": "0000-0002-7735-5796", "clpid": "Bright-Joe-S" }, { "family_name": "Fender", "given_name": "Rob", "orcid": "0000-0002-5654-2744", "clpid": "Fender-Rob" }, { "family_name": "Cackett", "given_name": "Edward M.", "orcid": "0000-0002-8294-9281", "clpid": "Cackett-Edward-M" }, { "family_name": "Remillard", "given_name": "Ron A.", "orcid": "0000-0003-4815-0481", "clpid": "Remillard-Ron-A" } ], "abstract": "We analyze five epochs of Neutron star Interior Composition Explorer (NICER) data of the black hole X-ray binary MAXI J1820+070 during the bright hard-to-soft state transition in its 2018 outburst with both reflection spectroscopy and Fourier-resolved timing analysis. We confirm the previous discovery of reverberation lags in the hard state, and find that the frequency range where the (soft) reverberation lag dominates decreases with the reverberation lag amplitude increasing during the transition, suggesting an increasing X-ray emitting region, possibly due to an expanding corona. By jointly fitting the lag-energy spectra in a number of broad frequency ranges with the reverberation model reltrans, we find the increase in reverberation lag is best described by an increase in the X-ray coronal height. This result, along with the finding that the corona contracts in the hard state, suggests a close relationship between spatial extent of the X-ray corona and the radio jet. We find the corona expansion (as probed by reverberation) precedes a radio flare by ~5 days, which may suggest that the hard-to-soft transition is marked by the corona expanding vertically and launching a jet knot that propagates along the jet stream at relativistic velocities.", "doi": "10.3847/2041-8213/abec79", "issn": "2041-8205", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal Letters", "publication_date": "2021-03-20", "series_number": "1", "volume": "910", "issue": "1", "pages": "Art. No. L3" }, { "id": "authors:dw4bc-17b78", "collection": "authors", "collection_id": "dw4bc-17b78", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210309-080810844", "type": "article", "title": "Reflection Modeling of the Black Hole Binary 4U 1630\u201347: The Disk Density and Returning Radiation", "author": [ { "family_name": "Connors", "given_name": "Riley M. T.", "orcid": "0000-0002-8908-759X", "clpid": "Connors-Riley-M-T" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Tomsick", "given_name": "John", "orcid": "0000-0001-5506-9855", "clpid": "Tomsick-John-A" }, { "family_name": "Hare", "given_name": "Jeremy", "orcid": "0000-0002-8548-482X", "clpid": "Hare-Jeremy" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-Thomas" }, { "family_name": "Grinberg", "given_name": "Victoria", "orcid": "0000-0003-2538-0188", "clpid": "Grinberg-Victoria" }, { "family_name": "Steiner", "given_name": "James F.", "orcid": "0000-0002-5872-6061", "clpid": "Steiner-James-F" }, { "family_name": "Mastroserio", "given_name": "Guglielmo", "orcid": "0000-0003-4216-7936", "clpid": "Mastroserio-Guglielmo" }, { "family_name": "Sridhar", "given_name": "Navin", "orcid": "0000-0002-5519-9550", "clpid": "Sridhar-Navin" }, { "family_name": "Fabian", "given_name": "Andrew C.", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-Andrew-C" }, { "family_name": "Jiang", "given_name": "Jiachen", "orcid": "0000-0002-9639-4352", "clpid": "Jiang-Jiachen" }, { "family_name": "Parker", "given_name": "Michael L.", "orcid": "0000-0002-8466-7317", "clpid": "Parker-Michael-L" }, { "family_name": "Harrison", "given_name": "Fiona", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" }, { "family_name": "Kallman", "given_name": "Timothy R.", "orcid": "0000-0002-5779-6906", "clpid": "Kallman-Timothy-R" } ], "abstract": "We present the analysis of X-ray observations of the black hole binary 4U 1630\u221247 using relativistic reflection spectroscopy. We use archival data from the Rossi X-ray Timing Explorer, Neil Gehrels Swift Observatory, and Nuclear Spectroscopic Telescope Array observatories, taken during different outbursts of the source between 1998 and 2015. Our modeling includes two relatively new advances in modern reflection codes: high-density disks, and returning thermal disk radiation. Accretion disks around stellar-mass black holes are expected to have densities well above the standard value assumed in traditional reflection models (i.e., ne ~ 10\u00b9\u2075 cm\u207b\u00b3). New high-density reflection models have important implications in the determination of disk truncation (i.e., the disk inner radius). This is because one must retain self-consistency in the irradiating flux and corresponding disk ionization state, which is a function of disk density and system geometry. We find that the disk density is n_e \u2265 10\u00b2\u2070 cm\u207b\u00b3 across all spectral states. This density, combined with our constraints on the ionization state of the material, implies an irradiating flux impinging on the disk that is consistent with the expected theoretical estimates. Returning thermal disk radiation\u2014the fraction of disk photons that bend back to the disk producing additional reflection components\u2014is expected predominantly in the soft state. We show that returning radiation models indeed provide a better fit to the soft-state data, reinforcing previous results that show that in the soft state, the irradiating continuum may be blackbody emission from the disk itself.", "doi": "10.3847/1538-4357/abdd2c", "issn": "1538-4357", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2021-03-10", "series_number": "2", "volume": "909", "issue": "2", "pages": "Art. No. 146" }, { "id": "authors:c925m-4e165", "collection": "authors", "collection_id": "c925m-4e165", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210305-073046158", "type": "article", "title": "StrayCats: A Catalog of NuSTAR Stray Light Observations", "author": [ { "family_name": "Grefenstette", "given_name": "Brian W.", "orcid": "0000-0002-1984-2932", "clpid": "Grefenstette-Brian-W" }, { "family_name": "Ludlam", "given_name": "Renee M.", "orcid": "0000-0002-8961-939X", "clpid": "Ludlam-Renee-M" }, { "family_name": "Thompson", "given_name": "Ellen T.", "orcid": "0000-0002-3669-2294", "clpid": "Thompson-Ellen-T" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Hare", "given_name": "Jeremy", "orcid": "0000-0002-8548-482X", "clpid": "Hare-Jeremy" }, { "family_name": "Jaodand", "given_name": "Amruta D.", "orcid": "0000-0002-3850-6651", "clpid": "Jaodand-Amruta-D" }, { "family_name": "Krivonos", "given_name": "Roman A.", "orcid": "0000-0003-2737-5673", "clpid": "Krivonos-Roman-A" }, { "family_name": "Madsen", "given_name": "Kristin K.", "orcid": "0000-0003-1252-4891", "clpid": "Madsen-Kristin-K" }, { "family_name": "Mastroserio", "given_name": "Guglielmo", "orcid": "0000-0003-4216-7936", "clpid": "Mastroserio-Guglielmo" }, { "family_name": "Slaughter", "given_name": "Catherine M.", "orcid": "0000-0002-5752-3780", "clpid": "Slaughter-Catherine-M" }, { "family_name": "Tomsick", "given_name": "John A.", "orcid": "0000-0001-5506-9855", "clpid": "Tomsick-John-A" }, { "family_name": "Wik", "given_name": "Daniel", "orcid": "0000-0001-9110-2245", "clpid": "Wik-Daniel" }, { "family_name": "Zoglauer", "given_name": "Andreas", "orcid": "0000-0001-9067-3150", "clpid": "Zoglauer-Andreas" } ], "abstract": "We present StrayCats, a catalog of NuSTAR stray light observations of X-ray sources. Stray light observations arise for sources 1\u00b0\u20134\u00b0 away from the telescope pointing direction. At this off-axis angle, X-rays pass through a gap between the optics and aperture stop and so do not interact with the X-ray optics; instead, they directly illuminate the NuSTAR focal plane. We have systematically identified and examined over 1400 potential observations resulting in a catalog of 436 telescope fields and 78 stray light sources that have been identified. The sources identified include historically known persistently bright X-ray sources, X-ray binaries in outburst, pulsars, and type I X-ray bursters. In this paper, we present an overview of the catalog, how we identified the StrayCats sources, and the analysis techniques required to produce high-level science products. Finally, we present a few brief examples of the science quality of these unique data.", "doi": "10.3847/1538-4357/abe045", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2021-03-01", "series_number": "1", "volume": "909", "issue": "1", "pages": "Art. No. 30" }, { "id": "authors:2mjes-2kb22", "collection": "authors", "collection_id": "2mjes-2kb22", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210208-140557446", "type": "article", "title": "The XSTAR Atomic Database", "author": [ { "family_name": "Mendoza", "given_name": "Claudio", "orcid": "0000-0002-2854-4806", "clpid": "Mendoza-Claudio" }, { "family_name": "Bautista", "given_name": "Manuel A.", "orcid": "0000-0002-5522-9705", "clpid": "Bautista-Manuel-A" }, { "family_name": "Deprince", "given_name": "J\u00e9r\u00f4me", "orcid": "0000-0002-3409-8232", "clpid": "Deprince-J\u00e9r\u00f4me" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Gatuzz", "given_name": "Efra\u00edn", "orcid": "0000-0002-3252-9633", "clpid": "Gatuzz-Efrain" }, { "family_name": "Gorczyca", "given_name": "Thomas W.", "orcid": "0000-0003-4117-5790", "clpid": "Gorczyca-Thomas-W" }, { "family_name": "Kallman", "given_name": "Timothy R.", "orcid": "0000-0002-5779-6906", "clpid": "Kallman-Timothy-R" }, { "family_name": "Palmeri", "given_name": "Patrick", "orcid": "0000-0002-4372-6798", "clpid": "Palmeri-Patrick" }, { "family_name": "Quinet", "given_name": "Pascal", "orcid": "0000-0002-3937-2640", "clpid": "Quinet-Pascal" }, { "family_name": "Witthoeft", "given_name": "Michael C.", "orcid": "0000-0001-6237-7776", "clpid": "Witthoeft-Michael-C" } ], "abstract": "We describe the atomic database of the xstar spectral modeling code, summarizing the systematic upgrades carried out in the past twenty years to enable the modeling of K-lines from chemical elements with atomic number Z\u226430 and recent extensions to handle high-density plasmas. Such plasma environments are found, for instance, in the inner region of accretion disks round compact objects (neutron stars and black holes), which emit rich information about the system's physical properties. Our intention is to offer a reliable modeling tool to take advantage of the outstanding spectral capabilities of the new generation of X-ray space telescopes (e.g., xrism and athena) to be launched in the coming years. Data curatorial aspects are discussed and an updated list of reference sources is compiled to improve the database provenance metadata. Two xstar spin-offs\u2014the ISMabs absorption model and the uaDB database\u2014are also described.", "doi": "10.3390/atoms9010012", "issn": "2218-2004", "publisher": "MDPI AG", "publication": "Atoms", "publication_date": "2021-03", "series_number": "1", "volume": "9", "issue": "1", "pages": "Art. No. 12" }, { "id": "authors:ev2j1-hkp66", "collection": "authors", "collection_id": "ev2j1-hkp66", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210217-152552788", "type": "article", "title": "Photoionization Models for High-density Gas", "author": [ { "family_name": "Kallman", "given_name": "T.", "orcid": "0000-0002-5779-6906", "clpid": "Kallman-Timothy-R" }, { "family_name": "Bautista", "given_name": "M.", "orcid": "0000-0001-6837-3055", "clpid": "Bautista-Manuel" }, { "family_name": "Deprince", "given_name": "J.", "orcid": "0000-0002-3409-8232", "clpid": "Deprince-J\u00e9r\u00f4me" }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Mendoza", "given_name": "C.", "orcid": "0000-0002-2854-4806", "clpid": "Mendoza-Claudio" }, { "family_name": "Ogorzalek", "given_name": "A.", "orcid": "0000-0003-4504-2557", "clpid": "Ogorzalek-Anna" }, { "family_name": "Palmeri", "given_name": "P.", "orcid": "0000-0002-4372-6798", "clpid": "Palmeri-Patrick" }, { "family_name": "Quinet", "given_name": "P.", "orcid": "0000-0002-3937-2640", "clpid": "Quinet-Pascal" } ], "abstract": "Relativistically broadened and redshifted 6.4\u20136.9 keV iron K lines are observed from many accretion powered objects, including X-ray binaries and active galactic nuclei. The existence of gas close to the central engine implies large radiation intensities and correspondingly large gas densities if the gas is to remain partially ionized. Simple estimates indicate that high gas densities are needed to allow for the survival of iron against ionization. These are high enough that rates for many atomic processes are affected by mechanisms related to interactions with nearby ions and electrons. Radiation intensities are high enough that stimulated processes can be important. Most models currently in use for interpreting relativistic lines use atomic rate coefficients designed for use at low densities and neglect stimulated processes. In our work so far we have presented atomic structure calculations with the goal of providing physically appropriate models at densities consistent with line-emitting gas near compact objects. In this paper we apply these rates to photoionization calculations, and produce ionization balance curves and X-ray emissivities and opacities that are appropriate for high densities and high radiation intensities. The final step in our program will be presented in a subsequent paper in which model atmosphere calculations will incorporate these rates into synthetic spectra.", "doi": "10.3847/1538-4357/abccd6", "issn": "1538-4357", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2021-02-10", "series_number": "1", "volume": "908", "issue": "1", "pages": "Art. No. 94" }, { "id": "authors:1y0p7-5vy53", "collection": "authors", "collection_id": "1y0p7-5vy53", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210205-145940595", "type": "article", "title": "Swift Multiwavelength Follow-up of LVC S200224ca and the Implications for Binary Black Hole Mergers", "author": [ { "family_name": "Klingler", "given_name": "N. J.", "orcid": "0000-0002-7465-0941", "clpid": "Klingler-Noel-J" }, { "family_name": "Lien", "given_name": "A.", "orcid": "0000-0002-7851-9756" }, { "family_name": "Oates", "given_name": "S. R.", "orcid": "0000-0001-9309-7873" }, { "family_name": "Kennea", "given_name": "J. A.", "orcid": "0000-0002-6745-4790" }, { "family_name": "Evans", "given_name": "P. A.", "orcid": "0000-0002-8465-3353" }, { "family_name": "Tohuvavohu", "given_name": "A.", "orcid": "0000-0002-2810-8764" }, { "family_name": "Zhang", "given_name": "B.", "orcid": "0000-0002-9725-2524" }, { "family_name": "Page", "given_name": "K. L.", "orcid": "0000-0001-5624-2613" }, { "family_name": "Cenko", "given_name": "S. B.", "orcid": "0000-0003-1673-970X" }, { "family_name": "Barthelmy", "given_name": "S. D." }, { "family_name": "Beardmore", "given_name": "A. P." }, { "family_name": "Bernardini", "given_name": "M. G.", "orcid": "0000-0001-6106-3046" }, { "family_name": "Breeveld", "given_name": "A. A.", "orcid": "0000-0002-0001-7270" }, { "family_name": "Brown", "given_name": "P. J.", "orcid": "0000-0001-6272-5507" }, { "family_name": "Burrows", "given_name": "D. N.", "orcid": "0000-0003-0729-1632" }, { "family_name": "Campana", "given_name": "S.", "orcid": "0000-0001-6278-1576" }, { "family_name": "Cusumano", "given_name": "G." }, { "family_name": "D'A\u00ec", "given_name": "A.", "orcid": "0000-0002-5042-1036" }, { "family_name": "D'Avanzo", "given_name": "P." }, { "family_name": "D'Elia", "given_name": "V.", "orcid": "0000-0002-7320-5862" }, { "family_name": "de Pasquale", "given_name": "M." }, { "family_name": "Emery", "given_name": "S. W. K." }, { "family_name": "Garc\u00eda", "given_name": "J.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Giommi", "given_name": "P.", "orcid": "0000-0002-2265-5003" }, { "family_name": "Gronwall", "given_name": "C.", "orcid": "0000-0001-6842-2371" }, { "family_name": "Hartmann", "given_name": "D. H.", "orcid": "0000-0002-8028-0991" }, { "family_name": "Krimm", "given_name": "H. A.", "orcid": "0000-0003-4348-6058" }, { "family_name": "Kuin", "given_name": "N. P. M.", "orcid": "0000-0003-4650-4186" }, { "family_name": "Malesani", "given_name": "D. B.", "orcid": "0000-0002-7517-326X" }, { "family_name": "Marshall", "given_name": "F. E.", "orcid": "0000-0002-3559-6305" }, { "family_name": "Melandri", "given_name": "A." }, { "family_name": "Nousek", "given_name": "J. A.", "orcid": "0000-0001-7084-4637" }, { "family_name": "O'Brien", "given_name": "P. T.", "orcid": "0000-0002-5128-1899" }, { "family_name": "Osborne", "given_name": "J. P.", "orcid": "0000-0002-1041-7542" }, { "family_name": "Palmer", "given_name": "D. M.", "orcid": "0000-0001-7128-0802" }, { "family_name": "Page", "given_name": "M. J.", "orcid": "0000-0002-6689-6271" }, { "family_name": "Perri", "given_name": "M.", "orcid": "0000-0003-3613-4409" }, { "family_name": "Racusin", "given_name": "J. L.", "orcid": "0000-0002-4744-9898" }, { "family_name": "Sakamoto", "given_name": "T.", "orcid": "0000-0001-6276-6616" }, { "family_name": "Sbarufatti", "given_name": "B.", "orcid": "0000-0001-6620-8347" }, { "family_name": "Schlieder", "given_name": "J. E.", "orcid": "0000-0001-5347-7062" }, { "family_name": "Siegel", "given_name": "M. H." }, { "family_name": "Tagliaferri", "given_name": "G.", "orcid": "0000-0003-0121-0723" }, { "family_name": "Troja", "given_name": "E.", "orcid": "0000-0002-1869-7817" } ], "abstract": "On 2020 February 24, during their third observing run (\"O3\"), the Laser Interferometer Gravitational-wave Observatory and Virgo Collaboration detected S200224ca: a candidate gravitational wave (GW) event produced by a binary black hole (BBH) merger. This event was one of the best-localized compact binary coalescences detected in O3 (with 50%/90% error regions of 13/72 deg\u00b2), and so the Neil Gehrels Swift Observatory performed rapid near-UV/X-ray follow-up observations. Swift-XRT and UVOT covered approximately 79.2% and 62.4% (respectively) of the GW error region, making S200224ca the BBH event most thoroughly followed-up in near-UV (u-band) and X-ray to date. No likely EM counterparts to the GW event were found by the Swift BAT, XRT, or UVOT, nor by other observatories. Here, we report on the results of our searches for an EM counterpart, both in the BAT data near the time of the merger, and in follow-up UVOT/XRT observations. We also discuss the upper limits we can place on EM radiation from S200224ca, as well as the implications these limits have on the physics of BBH mergers. Namely, we place a shallow upper limit on the dimensionless BH charge, q\u0302 < 1.4 \u00d7 10\u207b\u2074, and an upper limit on the isotropic-equivalent energy of a blast wave E < 4.1 \u00d7 10\u2075\u00b9 erg (assuming typical GRB parameters).", "doi": "10.3847/1538-4357/abd2c3", "issn": "1538-4357", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2021-02-01", "series_number": "2", "volume": "907", "issue": "2", "pages": "Art. No. 97" }, { "id": "authors:c4tzy-2eg85", "collection": "authors", "collection_id": "c4tzy-2eg85", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210112-151231714", "type": "article", "title": "A Variable Ionized Disk Wind in the Black Hole Candidate EXO 1846\u2013031", "author": [ { "family_name": "Wang", "given_name": "Yanan", "clpid": "Wang-Yanan" }, { "family_name": "Ji", "given_name": "Long" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048" }, { "family_name": "M\u00e9ndez", "given_name": "Mariano" }, { "family_name": "Mao", "given_name": "Junjie" }, { "family_name": "Tao", "given_name": "L.", "orcid": "0000-0002-2705-4338" }, { "family_name": "Altamirano", "given_name": "Diego", "orcid": "0000-0002-3422-0074" }, { "family_name": "Maggi", "given_name": "Pierre" }, { "family_name": "Zhang", "given_name": "S. N.", "orcid": "0000-0001-5586-1017" }, { "family_name": "Ge", "given_name": "M. Y.", "orcid": "0000-0002-2749-6638" }, { "family_name": "Zhang", "given_name": "L.", "orcid": "0000-0003-4498-9925" }, { "family_name": "Qu", "given_name": "J. L.", "orcid": "0000-0002-9796-2585" }, { "family_name": "Zhang", "given_name": "S." }, { "family_name": "Ma", "given_name": "X." }, { "family_name": "Lu", "given_name": "F. J.", "orcid": "0000-0003-3248-6087" }, { "family_name": "Li", "given_name": "T. P." }, { "family_name": "Huang", "given_name": "Y." }, { "family_name": "Zheng", "given_name": "S. J." }, { "family_name": "Chang", "given_name": "Z." }, { "family_name": "Tuo", "given_name": "Y. L." }, { "family_name": "Song", "given_name": "L. M." }, { "family_name": "Xu", "given_name": "Y. P." }, { "family_name": "Chen", "given_name": "Y.", "orcid": "0000-0001-9834-2196" }, { "family_name": "Liu", "given_name": "C. Z." }, { "family_name": "Bu", "given_name": "Q. C.", "orcid": "0000-0001-5238-3988" }, { "family_name": "Cai", "given_name": "C." }, { "family_name": "Cao", "given_name": "X. L." }, { "family_name": "Chen", "given_name": "L." }, { "family_name": "Chen", "given_name": "T. X." }, { "family_name": "Chen", "given_name": "Y. P." }, { "family_name": "Cui", "given_name": "W. W." }, { "family_name": "Du", "given_name": "Y. Y." }, { "family_name": "Gao", "given_name": "G. H." }, { "family_name": "Gu", "given_name": "Y. D." }, { "family_name": "Guan", "given_name": "J." }, { "family_name": "Guo", "given_name": "C. C." }, { "family_name": "Han", "given_name": "D. W." }, { "family_name": "Huo", "given_name": "J." }, { "family_name": "Jia", "given_name": "S. M.", "orcid": "0000-0002-5203-8321" }, { "family_name": "Jiang", "given_name": "W. C." }, { "family_name": "Jin", "given_name": "J." }, { "family_name": "Kong", "given_name": "L. D.", "orcid": "0000-0003-3188-9079" }, { "family_name": "Li", "given_name": "B.", "orcid": "0000-0002-0238-834X" }, { "family_name": "Li", "given_name": "C. K.", "orcid": "0000-0001-5798-4491" }, { "family_name": "Li", "given_name": "G.", "orcid": "0000-0001-5067-1599" }, { "family_name": "Li", "given_name": "W." }, { "family_name": "Li", "given_name": "X." }, { "family_name": "Li", "given_name": "X. B." }, { "family_name": "Li", "given_name": "X. F.", "orcid": "0000-0002-2793-9857" }, { "family_name": "Li", "given_name": "Z. W." }, { "family_name": "Liang", "given_name": "X. H." }, { "family_name": "Liao", "given_name": "J. Y." }, { "family_name": "Liu", "given_name": "H. W." }, { "family_name": "Liu", "given_name": "X. J." }, { "family_name": "Lu", "given_name": "X. F." }, { "family_name": "Luo", "given_name": "Q.", "orcid": "0000-0003-1853-7810" }, { "family_name": "Luo", "given_name": "T." }, { "family_name": "Meng", "given_name": "B." }, { "family_name": "Nang", "given_name": "Y." }, { "family_name": "Nie", "given_name": "J. Y." }, { "family_name": "Ou", "given_name": "G." }, { "family_name": "Sai", "given_name": "N." }, { "family_name": "Shang", "given_name": "R. C." }, { "family_name": "Song", "given_name": "X. Y." }, { "family_name": "Sun", "given_name": "L." }, { "family_name": "Tan", "given_name": "Y." }, { "family_name": "Wang", "given_name": "W. S." }, { "family_name": "Wang", "given_name": "Y. D." }, { "family_name": "Wang", "given_name": "Y. S." }, { "family_name": "Wen", "given_name": "X. Y." }, { "family_name": "Wu", "given_name": "B. B." }, { "family_name": "Wu", "given_name": "B. Y." }, { "family_name": "Wu", "given_name": "M." }, { "family_name": "Xiao", "given_name": "G. C." }, { "family_name": "Xiao", "given_name": "S." }, { "family_name": "Xiong", "given_name": "S. L." }, { "family_name": "Yang", "given_name": "S." }, { "family_name": "Yang", "given_name": "Y. J." }, { "family_name": "Yi", "given_name": "Q. B." }, { "family_name": "Yin", "given_name": "Q. Q.", "orcid": "0000-0001-7580-1513" }, { "family_name": "You", "given_name": "Y." }, { "family_name": "Zhang", "given_name": "F." }, { "family_name": "Zhang", "given_name": "H. M." }, { "family_name": "Zhang", "given_name": "J." }, { "family_name": "Zhang", "given_name": "W. C." }, { "family_name": "Zhang", "given_name": "W." }, { "family_name": "Zhang", "given_name": "Y. F." }, { "family_name": "Zhao", "given_name": "H. S." }, { "family_name": "Zhao", "given_name": "X. F." }, { "family_name": "Zhou", "given_name": "D. K." } ], "abstract": "After 34 yr, the black hole candidate EXO 1846\u2013031 went into outburst again in 2019. We investigate its spectral properties in the hard intermediate and the soft states with NuSTAR and Insight-HXMT. A reflection component has been detected in the two spectral states but possibly originating from different illumination spectra: in the intermediate state, the illuminating source is attributed to a hard coronal component, which has been commonly observed in other X-ray binaries, whereas in the soft state, the reflection is probably produced by disk self-irradiation. Both cases support EXO 1846\u2013031 as a low-inclination system of ~40\u00b0. An absorption line is clearly detected at ~7.2 keV in the hard intermediate state, corresponding to a highly ionized disk wind (log} \u03be > 6.1) with a velocity of up to 0.06c. Meanwhile, quasi-simultaneous radio emissions have been detected before and after the X-rays, implying the coexistence of disk winds and jets in this system. If only the high-flux segment of the NuSTAR observation is considered, the observed wind appears to be magnetically driven. The absorption line disappeared in the soft state and a narrow emission line appeared at ~6.7 keV on top of the reflection component, which may be evidence for disk winds, but data with higher spectral resolution are required to examine this.", "doi": "10.3847/1538-4357/abc55e", "issn": "1538-4357", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2021-01-01", "series_number": "1", "volume": "906", "issue": "1", "pages": "Art. No. 11" }, { "id": "authors:p3k1t-fh972", "collection": "authors", "collection_id": "p3k1t-fh972", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210209-120605988", "type": "article", "title": "A new lepto-hadronic model applied to the first simultaneous multiwavelength data set for Cygnus X\u20131", "author": [ { "family_name": "Kantzas", "given_name": "D.", "orcid": "0000-0002-7364-606X", "clpid": "Kantzas-Dimitrios" }, { "family_name": "Markoff", "given_name": "S.", "orcid": "0000-0001-9564-0876", "clpid": "Markoff-Sera" }, { "family_name": "Beuchert", "given_name": "T.", "clpid": "Beuchert-T" }, { "family_name": "Lucchini", "given_name": "M.", "orcid": "0000-0002-2235-3347", "clpid": "Lucchini-Matteo" }, { "family_name": "Chhotray", "given_name": "A.", "clpid": "Chhotray-A" }, { "family_name": "Ceccobello", "given_name": "C.", "orcid": "0000-0002-4767-9925", "clpid": "Ceccobello-Chiara" }, { "family_name": "Tetarenko", "given_name": "A. J.", "orcid": "0000-0003-3906-4354", "clpid": "Tetarenko-Alexandra-J" }, { "family_name": "Miller-Jones", "given_name": "J. C. A.", "orcid": "0000-0003-3124-2814", "clpid": "Miller-Jones-James-C-A" }, { "family_name": "Bremer", "given_name": "M.", "clpid": "Bremer-Malcolm-N" }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Grinberg", "given_name": "V.", "orcid": "0000-0003-2538-0188", "clpid": "Grinberg-Victoria" }, { "family_name": "Uttley", "given_name": "P.", "orcid": "0000-0001-9355-961X", "clpid": "Uttley-Phil" }, { "family_name": "Wilms", "given_name": "J.", "orcid": "0000-0003-2065-5410", "clpid": "Wilms-J\u00f6rn" } ], "abstract": "Cygnus X\u20131 is the first Galactic source confirmed to host an accreting black hole. It has been detected across the entire electromagnetic spectrum from radio to GeV gamma-rays. The source's radio through mid-infrared radiation is thought to originate from the relativistic jets. The observed high degree of linear polarization in the MeV X-rays suggests that the relativistic jets dominate in this regime as well, whereas a hot accretion flow dominates the soft X-ray band. The origin of the GeV non-thermal emission is still debated, with both leptonic and hadronic scenarios deemed to be viable. In this work, we present results from a new semi-analytical, multizone jet model applied to the broad-band spectral energy distribution of Cygnus X\u20131 for both leptonic and hadronic scenarios. We try to break this degeneracy by fitting the first-ever high-quality, simultaneous multiwavelength data set obtained from the CHOCBOX campaign (Cygnus X\u20131 Hard state Observations of a Complete Binary Orbit in X-rays). Our model parametrizes dynamical properties, such as the jet velocity profile, the magnetic field, and the energy density. Moreover, the model combines these dynamical properties with a self-consistent radiative transfer calculation including secondary cascades, both of leptonic and hadronic origin. We conclude that sensitive TeV gamma-ray telescopes like Cherenkov Telescope Array (CTA) will definitively answer the question of whether hadronic processes occur inside the relativistic jets of Cygnus X\u20131.", "doi": "10.1093/mnras/staa3349", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2021-01", "series_number": "2", "volume": "500", "issue": "2", "pages": "2112-2126" }, { "id": "authors:ac5t7-g5w98", "collection": "authors", "collection_id": "ac5t7-g5w98", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210104-164231707", "type": "article", "title": "Testing general relativity with x-ray reflection spectroscopy: The Konoplya-Rezzolla-Zhidenko parametrization", "author": [ { "family_name": "Nampalliwar", "given_name": "Sourabh", "orcid": "0000-0002-9608-1102", "clpid": "Nampalliwar-Sourabh" }, { "family_name": "Xin", "given_name": "Shuo", "clpid": "Xin-Shuo" }, { "family_name": "Srivastava", "given_name": "Shubham", "clpid": "Srivastava-Shubham" }, { "family_name": "Abdikamalov", "given_name": "Askar B.", "orcid": "0000-0002-7671-6457", "clpid": "Abdikamalov-Askar-B" }, { "family_name": "Ayzenberg", "given_name": "Dimitry", "orcid": "0000-0003-0238-6181", "clpid": "Ayzenberg-Dimitry" }, { "family_name": "Bambi", "given_name": "Cosimo", "orcid": "0000-0002-3180-9502", "clpid": "Bambi-Cosimo" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-Thomas" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Tripathi", "given_name": "Ashutosh", "orcid": "0000-0002-3960-5870", "clpid": "Tripathi-Ashutosh" } ], "abstract": "X-ray reflection spectroscopy is a promising technique for testing general relativity in the strong-field regime as it can be used to test the Kerr black hole hypothesis. In this context, the parametrically deformed black hole metrics proposed by Konoplya, Rezzolla, and Zhidenko [Phys. Rev. D 93, 064015 (2016)] form an important class of non-Kerr black holes. We implement this class of black hole metrics in relxill_nk, which is a framework we have developed for testing for non-Kerr black holes using x-ray reflection spectroscopy. We perform a qualitative analysis of the effect of the leading order strong-field deformation parameters on typical observables like the innermost stable circular orbits and the reflection spectra. We also present the first x-ray constraints on some of the deformation parameters of this metric, using Suzaku data from the supermassive black hole in Ark 564, and compare them with those obtained (or expected) from other observational techniques like gravitational waves and black hole imaging.", "doi": "10.1103/physrevd.102.124071", "issn": "2470-0010", "publisher": "American Physical Society", "publication": "Physical Review D", "publication_date": "2020-12-15", "series_number": "12", "volume": "102", "issue": "12", "pages": "Art. No. 124071" }, { "id": "authors:3kxbv-m9593", "collection": "authors", "collection_id": "3kxbv-m9593", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20201104-152054047", "type": "article", "title": "Plasma environment effects on K lines of astrophysical interest. IV. IPs, K thresholds, radiative rates, and Auger widths in Fe\u202fII\u2013Fe\u202fVIII", "author": [ { "family_name": "Deprince", "given_name": "J.", "orcid": "0000-0002-3409-8232", "clpid": "Deprince-J\u00e9r\u00f4me" }, { "family_name": "Bautista", "given_name": "M. A.", "clpid": "Bautista-M-A" }, { "family_name": "Fritzsche", "given_name": "S.", "clpid": "Fritzsche-Stephan" }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Kallman", "given_name": "T. R.", "orcid": "0000-0002-5779-6906", "clpid": "Kallman-Timothy-R" }, { "family_name": "Mendoza", "given_name": "C.", "clpid": "Mendoza-C" }, { "family_name": "Palmeri", "given_name": "P.", "clpid": "Palmeri-P" }, { "family_name": "Quinet", "given_name": "P.", "clpid": "Quinet-P" } ], "abstract": "Aims. Within the framework of compact-object accretion disks, we calculate plasma environment effects on the atomic structure and decay parameters used in the modeling of K lines in lowly charged iron ions, namely Fe\u202fII\u2013Fe\u202fVIII. \n\nMethods. For this study, we used the fully relativistic multiconfiguration Dirac\u2013Fock method approximating the plasma electron\u2013nucleus and electron-electron screenings with a time-averaged Debye-H\u00fcckel potential. \n\nResults. We report modified ionization potentials, K-threshold energies, wavelengths, radiative emission rates, and Auger widths for plasmas characterized by electron temperatures and densities in the ranges 10\u2075 \u2212 10\u2077 K and 10\u00b9\u2078 \u2212 10\u00b2\u00b2 cm\u207b\u00b3. In addition, we propose two universal fitting formulae to predict the IP and K-threshold lowerings in any elemental ion. \n\nConclusions. We conclude that the high-resolution X-ray spectrometers onboard the future XRISM and ATHENA space missions will be able to detect the lowering of the K edges of these Fe ions due to the extreme plasma conditions occurring in the accretion disks around compact objects.", "doi": "10.1051/0004-6361/202038659", "issn": "0004-6361", "publisher": "EDP Sciences", "publication": "Astronomy and Astrophysics", "publication_date": "2020-11", "volume": "643", "pages": "Art. No. A57" }, { "id": "authors:70g6h-f2456", "collection": "authors", "collection_id": "70g6h-f2456", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20201204-161632433", "type": "article", "title": "Returning radiation in strong gravity around black holes: reverberation from the accretion disc", "author": [ { "family_name": "Wilkins", "given_name": "D. R.", "orcid": "0000-0002-4794-5998", "clpid": "Wilkins-Dan-R" }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Dauser", "given_name": "T.", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-Thomas" }, { "family_name": "Fabian", "given_name": "A. C.", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-Andrew-C" } ], "abstract": "We study reflected X-ray emission that returns to the accretion disc in the strong gravitational fields around black holes using General Relativistic ray-tracing and radiative transfer calculations. Reflected X-rays that are produced when the inner regions of the disc are illuminated by the corona are subject to strong gravitational light bending, causing up to 47 per\u2009cent of the reflected emission to be returned to the disc around a rapidly spinning black hole, depending upon the scale height of the corona. The iron K\u03b1 line is enhanced relative to the continuum by 25 per\u2009cent, and the Compton hump by up to a factor of 3. Additional light traveltime between primary and secondary reflections increases the reverberation time lag measured in the iron K band by 49 per\u2009cent, while the soft X-ray lag is increased by 25 per\u2009cent and the Compton hump response time is increased by 60 per\u2009cent. Measured samples of X-ray reverberation lags are shown to be consistent with X-rays returning to the accretion disc in strong gravity. Understanding the effects of returning radiation is important in interpreting reverberation observations to probe black holes. Reflected X-rays returning to the disc can be uniquely identified by blueshifted returning iron K line photons that are Compton scattered from the inner disc, producing excess, delayed emission in the 3.5\u20134.5\u2009keV energy range that will be detectable with forthcoming X-ray observatories, representing a unique test of General Relativity in the strong field limit.", "doi": "10.1093/mnras/staa2566", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2020-11", "series_number": "3", "volume": "498", "issue": "3", "pages": "3302-3319" }, { "id": "authors:25163-a6p86", "collection": "authors", "collection_id": "25163-a6p86", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20201214-104307005", "type": "article", "title": "A full characterization of the supermassive black hole in IRAS\u200909149\u20136206", "author": [ { "family_name": "Walton", "given_name": "D. J.", "orcid": "0000-0001-5819-3552", "clpid": "Walton-Dominic-J" }, { "family_name": "Alston", "given_name": "W. N.", "orcid": "0000-0003-2658-6559", "clpid": "Alston-William-N" }, { "family_name": "Kosec", "given_name": "P.", "clpid": "Kosec-P" }, { "family_name": "Fabian", "given_name": "A. C.", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-Andrew-C" }, { "family_name": "Gallo", "given_name": "L. C.", "clpid": "Gallo-L-C" }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Miller", "given_name": "J. M.", "clpid": "Miller-Jon-M" }, { "family_name": "Nardini", "given_name": "E.", "orcid": "0000-0001-9226-8992", "clpid": "Nardini-Emanuele" }, { "family_name": "Reynolds", "given_name": "M. T.", "clpid": "Reynolds-M-T" }, { "family_name": "Ricci", "given_name": "C.", "orcid": "0000-0001-5231-2645", "clpid": "Ricci-Claudio" }, { "family_name": "Stern", "given_name": "D.", "orcid": "0000-0003-2686-9241", "clpid": "Stern-Daniel" }, { "family_name": "Dauser", "given_name": "T.", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-Thomas" }, { "family_name": "Harrison", "given_name": "F. A.", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" }, { "family_name": "Reynolds", "given_name": "C. S.", "orcid": "0000-0002-1510-4860", "clpid": "Reynolds-Christopher-S" } ], "abstract": "We present new broad-band X-ray observations of the type-I Seyfert galaxy IRAS\u200909149\u20136206, taken in 2018 with XMM\u2013Newton, NuSTAR, and Swift. The source is highly complex, showing a classic 'warm' X-ray absorber, additional absorption from highly ionized iron, strong relativistic reflection from the innermost accretion disc and further reprocessing by more distant material. By combining X-ray timing and spectroscopy, we have been able to fully characterize the supermassive black hole in this system, constraining both its mass and \u2013 for the first time \u2013 its spin. The mass is primarily determined by X-ray timing constraints on the break frequency seen in the power spectrum, and is found to be log\u2009[M_(BH)/M_\u2299] = 8.0 \u00b1 0.6 (1\u03c3 uncertainties). This is in good agreement with previous estimates based on the H\u2009\u03b1 and H\u2009\u03b2 line widths, and implies that IRAS\u200909149\u20136206 is radiating at close to (but still below) its Eddington luminosity. The spin is constrained via detailed modelling of the relativistic reflection, and is found to be a\u2217 = 0.94^(+0.02)_(\u22120.07) (90 per cent confidence), adding IRAS\u200909149\u20136206 to the growing list of radio-quiet active galactic nuclei (AGNs) that host rapidly rotating black holes. The outflow velocities of the various absorption components are all relatively modest (v_(out) \u2272 0.03c), implying these are unlikely to drive significant galaxy-scale AGN feedback.", "doi": "10.1093/mnras/staa2961", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2020-11", "series_number": "1", "volume": "499", "issue": "1", "pages": "1480-1498" }, { "id": "authors:0c0te-08q10", "collection": "authors", "collection_id": "0c0te-08q10", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200811-131238093", "type": "article", "title": "Relativistic Reflection and Reverberation in GX 339\u20134 with NICER and NuSTAR", "author": [ { "family_name": "Wang", "given_name": "Jingyi", "orcid": "0000-0002-1742-2125", "clpid": "Wang-Jingyi" }, { "family_name": "Kara", "given_name": "Erin", "orcid": "0000-0003-0172-0854", "clpid": "Kara-E" }, { "family_name": "Steiner", "given_name": "James F.", "orcid": "0000-0002-5872-6061", "clpid": "Steiner-J-F" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Homan", "given_name": "Jeroen", "orcid": "0000-0001-8371-2713", "clpid": "Homan-J" }, { "family_name": "Neilsen", "given_name": "Joseph", "orcid": "0000-0002-8247-786X", "clpid": "Neilsen-J" }, { "family_name": "Marcel", "given_name": "Gr\u00e9goire", "orcid": "0000-0003-1780-5641", "clpid": "Marcel-G" }, { "family_name": "Ludlam", "given_name": "Renee M.", "orcid": "0000-0002-8961-939X", "clpid": "Ludlam-R-M" }, { "family_name": "Tombesi", "given_name": "Francesco", "orcid": "0000-0002-6562-8654", "clpid": "Tombesi-F" }, { "family_name": "Cackett", "given_name": "Edward M.", "orcid": "0000-0002-8294-9281", "clpid": "Cackett-E-M" }, { "family_name": "Remillard", "given_name": "Ron A.", "orcid": "0000-0003-4815-0481", "clpid": "Remillard-R-A" } ], "abstract": "We analyze seven Neutron Star Interior Composition Interior Explorer (NICER) and Nuclear Spectroscopic Telescope Array epochs of the black hole X-ray binary GX 339\u20134 in the hard state during its two most recent hard-only outbursts in 2017 and 2019. These observations cover the 1\u2013100 keV unabsorbed luminosities between 0.3% and 2.1% of the Eddington limit. With NICER's negligible pileup, high count rate, and unprecedented time resolution, we perform a spectral-timing analysis and spectral modeling using relativistic and distant reflection models. Our spectral fitting shows that as the inner disk radius moves inward, the thermal disk emission increases in flux and temperature, the disk becomes more highly ionized, and the reflection fraction increases. This coincides with the inner disk increasing its radiative efficiency around ~1% Eddington. We see a hint of the hysteresis effect at ~0.3% of Eddington; the inner radius is significantly truncated during the rise (>49R_g ), while only a mild truncation (~5R_g ) is found during the decay. At higher frequencies (2\u20137 Hz) in the highest-luminosity epoch, a soft lag is present whose energy dependence reveals a thermal reverberation lag with an amplitude similar to previous findings for this source. We also discuss the plausibility of the hysteresis effect and the debate of the disk truncation problem in the hard state.", "doi": "10.3847/1538-4357/ab9ec3", "issn": "1538-4357", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2020-08-10", "series_number": "1", "volume": "899", "issue": "1", "pages": "Art. No. 44" }, { "id": "authors:cgn7x-fgm39", "collection": "authors", "collection_id": "cgn7x-fgm39", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200414-071310777", "type": "article", "title": "Testing the Kerr black hole hypothesis using X-ray reflection spectroscopy and a thin disk model with finite thickness", "author": [ { "family_name": "Abdikamalov", "given_name": "Askar B.", "orcid": "0000-0002-7671-6457", "clpid": "Abdikamalov-A-B" }, { "family_name": "Ayzenberg", "given_name": "Dimitry", "orcid": "0000-0003-0238-6181", "clpid": "Ayzenberg-D" }, { "family_name": "Bambi", "given_name": "Cosimo", "orcid": "0000-0002-3180-9502", "clpid": "Bambi-C" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-T" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Nampalliwar", "given_name": "Sourabh", "orcid": "0000-0002-9608-1102", "clpid": "Nampalliwar-S" }, { "family_name": "Tripathi", "given_name": "Ashutosh", "orcid": "0000-0002-3960-5870", "clpid": "Tripathi-A" }, { "family_name": "Zhou", "given_name": "Menglei", "clpid": "Zhou-Menglei" } ], "abstract": "X-ray reflection spectroscopy is a powerful tool for probing the strong gravity region of black holes and can be used for testing general relativity in the strong field regime. Simplifications of the available relativistic reflection models limit the capability of performing accurate measurements of the properties of black holes. In this paper, we present an extension of the model relxill_nk in which the accretion disk has a finite thickness rather than being infinitesimally thin. We employ the accretion disk geometry proposed by Taylor & Reynolds and we construct relativistic reflection models for different values of the mass accretion rate of the black hole. We apply the new model to high-quality Suzaku data of the X-ray binary GRS 1915+105 to explore the impact of the thickness of the disk on tests of the Kerr metric.", "doi": "10.3847/1538-4357/aba625", "issn": "1538-4357", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2020-08-10", "series_number": "1", "volume": "899", "issue": "1", "pages": "Art. No. 80" }, { "id": "authors:4e2px-xpv22", "collection": "authors", "collection_id": "4e2px-xpv22", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200604-151447853", "type": "article", "title": "Accurate Treatment of Comptonization in X-ray Illuminated Accretion Disks", "author": [ { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Sokolova-Lapa", "given_name": "Ekaterina", "clpid": "Sokolova-Lapa-E" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-T" }, { "family_name": "Madej", "given_name": "Jerzy", "orcid": "0000-0001-8417-1509", "clpid": "Madej-J" }, { "family_name": "R\u00f3\u017ca\u0144ska", "given_name": "Agata", "orcid": "0000-0002-5275-4096", "clpid": "R\u00f3\u017ca\u0144ska-A" }, { "family_name": "Majczyna", "given_name": "Agnieszka", "clpid": "Majczyna-A" }, { "family_name": "Harrison", "given_name": "Fiona A.", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" }, { "family_name": "Wilms", "given_name": "J\u00f6rn", "orcid": "0000-0003-2065-5410", "clpid": "Wilms-J" } ], "abstract": "A large fraction of accreting black hole and neutron star systems present clear evidence of the reprocessing of X-rays in the atmosphere of an optically thick accretion disk. The main hallmarks of X-ray reflection include fluorescent K-shell emission lines from iron (~6.4\u20136.9 keV), the absorption iron K-edge (~7\u20139 keV), and a broad featureless component known as the Compton hump (~20\u201340 keV). This Compton hump is produced as the result of the scattering of high-energy photons (E \u2273 10 keV) of the relatively colder electrons (T_e ~ 10\u2075\u201310\u2077 K) in the accretion disk, in combination with photoelectric absorption from iron. The treatment of this process in most current models of ionized X-ray reflection has been done using an approximated Gaussian redistribution kernel. This approach works sufficiently well up to ~100 keV, but it becomes largely inaccurate at higher energies and at relativistic temperatures (T_e ~ 10\u2079 K). We present new calculations of X-ray reflection using a modified version of our code xillver, including an accurate solution for Compton scattering of the reflected unpolarized photons in the disk atmosphere. This solution takes into account quantum electrodynamic and relativistic effects allowing the correct treatment of high photon energies and electron temperatures. We show new reflection spectra computed with this model, and discuss the improvements achieved in reproducing the correct shape of the Compton hump, the discrepancies with previous calculations, and the expected impact of these new models in the interpretation of observational data.", "doi": "10.3847/1538-4357/ab919b", "issn": "1538-4357", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2020-07-01", "series_number": "1", "volume": "897", "issue": "1", "pages": "Art. No. 67" }, { "id": "authors:agkm8-m5742", "collection": "authors", "collection_id": "agkm8-m5742", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200522-131436417", "type": "article", "title": "NICER\u2013NuSTAR Observations of the Neutron Star Low-mass X-Ray Binary 4U 1735\u201344", "author": [ { "family_name": "Ludlam", "given_name": "R. M.", "orcid": "0000-0002-8961-939X", "clpid": "Ludlam-R-M" }, { "family_name": "Cackett", "given_name": "E. M.", "orcid": "0000-0002-8294-9281", "clpid": "Cackett-E-M" }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Miller", "given_name": "J. M.", "clpid": "Miller-J-M" }, { "family_name": "Bult", "given_name": "P. M.", "clpid": "Bult-P-M" }, { "family_name": "Strohmayer", "given_name": "T. E.", "orcid": "0000-0001-7681-5845", "clpid": "Strohmayer-T-E" }, { "family_name": "Guillot", "given_name": "S.", "orcid": "0000-0002-6449-106X", "clpid": "Guillot-S" }, { "family_name": "Jaisawal", "given_name": "G. K.", "orcid": "0000-0002-6789-2723", "clpid": "Jaisawal-G-K" }, { "family_name": "Malacaria", "given_name": "C.", "orcid": "0000-0002-0380-0041", "clpid": "Malacaria-C" }, { "family_name": "Fabian", "given_name": "A. C.", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-A-C" }, { "family_name": "Markwardt", "given_name": "C. B.", "orcid": "0000-0001-9803-3879", "clpid": "Markwardt-C-B" } ], "abstract": "We report on the first simultaneous Neutron Star Interior Composition Explore (NICER) and Nuclear Spectroscopic Telescope Array (NuSTAR) observations of the neutron star (NS) low-mass X-ray binary 4U 1735\u221244, obtained in 2018 August. The source was at a luminosity of ~1.8 (D/5.6 kpc) \u00b2 \u00d7 10\u00b3\u2077 erg s\u207b\u00b9 in the 0.4\u201330 keV band. We account for the continuum emission with two different continuum descriptions that have been used to model the source previously. Despite the choice in continuum model, the combined passband reveals a broad Fe K line indicative of reflection in the spectrum. In order to account for the reflection spectrum we utilize a modified version of the reflection model RELXILL that is tailored for thermal emission from accreting NSs. Alternatively, we also use the reflection convolution model of RFXCONV to model the reflected emission that would arise from a Comptonized thermal component for comparison. We determine that the innermost region of the accretion disk extends close to the innermost stable circular orbit (R_(ISCO)) at the 90% confidence level regardless of reflection model. Moreover, the current flux calibration of NICER is within 5% of the NuSTAR/FPMA(B).", "doi": "10.3847/1538-4357/ab89a6", "issn": "1538-4357", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2020-05-20", "series_number": "1", "volume": "895", "issue": "1", "pages": "Art. No. 45" }, { "id": "authors:6hfwh-n4e42", "collection": "authors", "collection_id": "6hfwh-n4e42", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20181009-091424392", "type": "article", "title": "Testing the Kerr metric using X-ray reflection spectroscopy: spectral analysis of GX 339-4", "author": [ { "family_name": "Wang", "given_name": "Jingyi", "orcid": "0000-0002-1742-2125", "clpid": "Wang-Jingyi" }, { "family_name": "Abdikamalov", "given_name": "Askar B.", "clpid": "Abdikamalov-A-B" }, { "family_name": "Ayzenberg", "given_name": "Dimitry", "clpid": "Ayzenberg-D" }, { "family_name": "Bambi", "given_name": "Cosimo", "orcid": "0000-0002-3180-9502", "clpid": "Bambi-C" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-T" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Nampalliwar", "given_name": "Sourabh", "clpid": "Nampalliwar-S" }, { "family_name": "Steiner", "given_name": "James F.", "orcid": "0000-0002-5872-6061", "clpid": "Steiner-J-F" } ], "abstract": "Signatures of X-ray reprocessing (reflection) out of an accretion disk are commonly observed in the high-energy spectrum of accreting black holes, and can be used to probe the strong gravity region around these objects. In this paper, we extend previous work in the literature and we employ a full emission model for relativistic reflection in non-Kerr spacetime to demonstrate an approach that tests the Kerr black hole hypothesis. We analyze a composite spectrum obtained with the Proportional Counter Array in the Rossi X-ray Timing Explorer (RXTE), of the stellar-mass black hole GX 339\u22124 in its brightest hard state. With a remarkable sensitivity of ~0.1% and 40 million counts in the 3\u201345 keV band to capture the faint features in the reflection spectrum, we demonstrate that it is possible with existing data and an adequate model to place constraints on the black hole spin a* and the deformation parameter that quantifies the departure from the Kerr metric. Our measurement obtained with the best fit model, which should be regarded as principally a proof of concept, is a*=0.92^(+0.07)_(\u22120.12) and \u03b1\u2081\u2083=\u22120.76^(+0.78)_(\u22120.60) with a 90% confidence level and is consistent with the hypothesis that the compact object in GX 339\u22124 is a Kerr black hole. We also discuss how the physical model choice and the emissivity profile adopted could make an impact on the constraints of \u03b113 and spin. To enable Kerr metric test using X-ray reflection spectroscopy, it is essential to improve our astrophysical understanding of accreting black holes, e.g., the natures of accretion flow and corona.", "doi": "10.1088/1475-7516/2020/05/026", "issn": "1475-7516", "publisher": "IOP", "publication": "Journal of Cosmology and Astroparticle Physics", "publication_date": "2020-05", "series_number": "5", "volume": "2020", "issue": "5", "pages": "Art. No. 26" }, { "id": "authors:sm3vt-p5e61", "collection": "authors", "collection_id": "sm3vt-p5e61", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200413-123514628", "type": "article", "title": "Studying the Reflection Spectra of the New Black Hole X-Ray Binary Candidate MAXI J1631\u2212479 Observed by NuSTAR: A Variable Broad Iron Line Profile", "author": [ { "family_name": "Xu", "given_name": "Yanjun", "orcid": "0000-0003-2443-3698", "clpid": "Xu-Yanjun" }, { "family_name": "Harrison", "given_name": "Fiona A.", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" }, { "family_name": "Tomsick", "given_name": "John A.", "orcid": "0000-0001-5506-9855", "clpid": "Tomsick-J-A" }, { "family_name": "Walton", "given_name": "Dominic J.", "orcid": "0000-0001-5819-3552", "clpid": "Walton-D-J" }, { "family_name": "Barret", "given_name": "Didier", "orcid": "0000-0002-0393-9190", "clpid": "Barret-D" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Hare", "given_name": "Jeremy", "orcid": "0000-0002-8548-482X", "clpid": "Hare-J" }, { "family_name": "Parker", "given_name": "Michael L.", "orcid": "0000-0002-8466-7317", "clpid": "Parker-M-L" } ], "abstract": "We present results from the Nuclear Spectroscopic Telescope Array observations of the new black hole X-ray binary candidate MAXI J1631\u2013479 at two epochs during its 2018\u20132019 outburst, which caught the source in a disk dominant state and a power-law dominant state. Strong relativistic disk reflection features are clearly detected, displaying significant variations in the shape and strength of the broad iron emission line between the two states. Spectral modeling of the reflection spectra reveals that the inner radius of the optically thick accretion disk evolves from <1.9 r_g to 12 \u00b1 1 r_g (statistical errors at 90% confidence level) from the disk dominant to the power-law dominant state. Assuming in the former case that the inner disk radius is consistent with being at the innermost stable circular orbit, we estimate a black hole spin of a* > 0.94. Given that the bolometric luminosity is similar in the two states, our results indicate that the disk truncation observed in MAXI J1631\u2013479 in the power-law dominant state is unlikely to be driven by a global variation in the accretion rate. We propose that it may instead arise from local instabilities in the inner edge of the accretion disk at high accretion rates. In addition, we find an absorption feature in the spectra centered at 7.33 \u00b1 0.03 keV during the disk dominant state, which is evidence for the rare case that an extremely fast disk wind (v_(out) = 0.067^(+0.001)_(\u22120.004) c) is observed in a low-inclination black hole binary, with the viewing angle of 29\u00b0 \u00b1 1\u00b0 as determined by the reflection modeling.", "doi": "10.3847/1538-4357/ab7dc0", "issn": "1538-4357", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2020-04-10", "series_number": "1", "volume": "893", "issue": "1", "pages": "Art. No. 30" }, { "id": "authors:qfqe4-rv948", "collection": "authors", "collection_id": "qfqe4-rv948", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200430-151241422", "type": "article", "title": "Blueshifted absorption lines from X-ray reflection in IRAS\u00a013224\u22123809", "author": [ { "family_name": "Fabian", "given_name": "A. C.", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-A-C" }, { "family_name": "Reynolds", "given_name": "C. S.", "clpid": "Reynolds-C-S" }, { "family_name": "Jiang", "given_name": "J.", "orcid": "0000-0002-9639-4352", "clpid": "Jiang-Jiachen" }, { "family_name": "Pinto", "given_name": "C.", "orcid": "0000-0003-2532-7379", "clpid": "Pinto-C" }, { "family_name": "Gallo", "given_name": "L. C.", "clpid": "Gallo-L-C" }, { "family_name": "Parker", "given_name": "M. L.", "orcid": "0000-0002-8466-7317", "clpid": "Parker-M-L" }, { "family_name": "Lasenby", "given_name": "A. N.", "clpid": "Lasenby-A-N" }, { "family_name": "Alston", "given_name": "W. N.", "orcid": "0000-0003-2658-6559", "clpid": "Alston-W-N" }, { "family_name": "Buisson", "given_name": "D. J. K.", "clpid": "Buisson-D-J-K" }, { "family_name": "Cackett", "given_name": "E. M.", "orcid": "0000-0002-8294-9281", "clpid": "Cackett-E-M" }, { "family_name": "De\u00a0Marco", "given_name": "B.", "clpid": "De-Marco-B" }, { "family_name": "Garc\u00eda", "given_name": "J.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Kara", "given_name": "E.", "orcid": "0000-0003-0172-0854", "clpid": "Kara-E" }, { "family_name": "Kosec", "given_name": "P.", "clpid": "Kosec-P" }, { "family_name": "Middleton", "given_name": "M. J.", "orcid": "0000-0002-8183-2970", "clpid": "Middleton-M-J" }, { "family_name": "Miller", "given_name": "J. M.", "clpid": "Miller-J-M" }, { "family_name": "Miniutti", "given_name": "G.", "clpid": "Miniutti-G" }, { "family_name": "Walton", "given_name": "D. J.", "orcid": "0000-0001-5819-3552", "clpid": "Walton-D-J" }, { "family_name": "Wilkins", "given_name": "D. R.", "orcid": "0000-0002-4794-5998", "clpid": "Wilkins-D-R" }, { "family_name": "Young", "given_name": "A. J.", "orcid": "0000-0003-3626-9151", "clpid": "Young-A-J" } ], "abstract": "We explore a disc origin for the highly blueshifted, variable absorption lines seen in the X-ray spectrum of the narrow-line Seyfert 1 galaxy IRAS 13224\u22123809. The blueshift corresponds to a velocity of \u223c0.25c. Such features in other active galactic nuclei are often interpreted as ultrafast outflows. The velocity is of course present in the orbital motions of the inner disc. The absorption lines in IRAS 13224\u22123809 are best seen when the flux is low and the reflection component of the disc is strong relative to the power-law continuum. The spectra are consistent with a model in which the reflection component passes through a thin, highly ionized absorbing layer at the surface of the inner disc, the blueshifted side of which dominates the flux due to relativistic aberration (the disc inclination is about 70\u00b0). No fast outflow need occurs beyond the disc.", "doi": "10.1093/mnras/staa482", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2020-04-01", "series_number": "2", "volume": "493", "issue": "2", "pages": "2518-2522" }, { "id": "authors:5fkcj-qzc88", "collection": "authors", "collection_id": "5fkcj-qzc88", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200414-142815441", "type": "article", "title": "A detailed study on the reflection component for the black hole candidate MAXI J1836\u2212194", "author": [ { "family_name": "Dong", "given_name": "Yanting", "clpid": "Dong-Yanting" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Liu", "given_name": "Zhu", "orcid": "0000-0003-3014-8762", "clpid": "Liu-Zhu" }, { "family_name": "Zhao", "given_name": "Xueshan", "clpid": "Zhao-Xueshan" }, { "family_name": "Zheng", "given_name": "Xueying", "orcid": "0000-0001-7386-4609", "clpid": "Zheng-Xueying" }, { "family_name": "Gou", "given_name": "Lijun", "clpid": "Gou-Lijun" } ], "abstract": "We present a detailed spectral analysis of the black hole candidate MAXI J1836\u2212194. The source was caught in the intermediate state during its 2011 outburst by Suzaku and RXTE. We jointly fit the X-ray data from these two missions using the relxill model to study the reflection component, and a steep inner emissivity profile indicating a compact corona as the primary source is required in order to achieve a good fit. In addition, a reflection model with a lamp-post configuration (relxilllp), which is normally invoked to explain the steep emissivity profile, gives a worse fit and is excluded at 99 per\u2009cent confidence level compared to relxill. We also explore the effect of the ionization gradient on the emissivity profile by fitting the data with two relativistic reflection components, and it is found that the inner emissivity flattens. These results may indicate that the ionization state of the disc is not constant. All the models above require a supersolar iron abundance higher than \u223c4.5. However, we find that the high-density version of reflionx can describe the same spectra even with solar iron abundance well. A moderate rotating black hole (a* = 0.84\u20130.94) is consistently obtained by our models, which is in agreement with previously reported values.", "doi": "10.1093/mnras/staa401", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2020-04", "series_number": "2", "volume": "493", "issue": "2", "pages": "2178-2187" }, { "id": "authors:9zmvm-tx938", "collection": "authors", "collection_id": "9zmvm-tx938", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200415-075915052", "type": "article", "title": "The soft state of the black hole transient source MAXI\u2009J1820+070: emission from the edge of the plunge region?", "author": [ { "family_name": "Fabian", "given_name": "A. C.", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-A-C" }, { "family_name": "Buisson", "given_name": "D. J.", "clpid": "Buisson-D-J-K" }, { "family_name": "Kosec", "given_name": "P.", "clpid": "Kosec-P" }, { "family_name": "Reynolds", "given_name": "C. S.", "clpid": "Reynolds-C-S" }, { "family_name": "Wilkins", "given_name": "D. R.", "orcid": "0000-0002-4794-5998", "clpid": "Wilkins-D-R" }, { "family_name": "Tomsick", "given_name": "J. A.", "orcid": "0000-0001-5506-9855", "clpid": "Tomsick-J-A" }, { "family_name": "Walton", "given_name": "D. J.", "orcid": "0000-0001-5819-3552", "clpid": "Walton-D-J" }, { "family_name": "Gandhi", "given_name": "P.", "orcid": "0000-0003-3105-2615", "clpid": "Gandhi-Poshak" }, { "family_name": "Altamirano", "given_name": "D.", "orcid": "0000-0002-3422-0074", "clpid": "Altamirano-D" }, { "family_name": "Arzoumanian", "given_name": "Z.", "clpid": "Arzoumanian-Z" }, { "family_name": "Cackett", "given_name": "E. M.", "orcid": "0000-0002-8294-9281", "clpid": "Cackett-E-M" }, { "family_name": "Dyda", "given_name": "S.", "clpid": "Dyda-S" }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Gendreau", "given_name": "K. C.", "clpid": "Gendreau-K-C" }, { "family_name": "Grefenstette", "given_name": "B. W.", "orcid": "0000-0002-1984-2932", "clpid": "Grefenstette-B-W" }, { "family_name": "Homan", "given_name": "J.", "orcid": "0000-0001-8371-2713", "clpid": "Homan-J" }, { "family_name": "Kara", "given_name": "E.", "orcid": "0000-0003-0172-0854", "clpid": "Kara-E" }, { "family_name": "Ludlam", "given_name": "R. M.", "orcid": "0000-0002-8961-939X", "clpid": "Ludlam-R-M" }, { "family_name": "Miller", "given_name": "J. M.", "clpid": "Miller-J-M" }, { "family_name": "Steiner", "given_name": "J. F.", "orcid": "0000-0002-5872-6061", "clpid": "Steiner-J-F" } ], "abstract": "The Galactic black hole X-ray binary MAXI J1820+070 had a bright outburst in 2018 when it became the second brightest X-ray source in the sky. It was too bright for X-ray CCD instruments such as XMM\u2013Newton and Chandra, but was well observed by photon-counting instruments such as Neutron star Inner Composition Explorer (NICER) and Nuclear Spectroscopic Telescope Array(NuSTAR). We report here on the discovery of an excess-emission component during the soft state. It is best modelled with a blackbody spectrum in addition to the regular disc emission, modelled as either diskbb or kerrbb. Its temperature varies from about 0.9 to 1.1 keV, which is about 30\u201380 per cent higher than the inner disc temperature of diskbb. Its flux varies between 4 and 12 per cent of the disc flux. Simulations of magnetized accretion discs have predicted the possibility of excess emission associated with a non-zero torque at the innermost stable circular orbit (ISCO) about the black hole, which, from other NuSTAR studies, lies at about 5 gravitational radii or about 60 km (for a black hole, mass is 8M\u2299). In this case, the emitting region at the ISCO has a width varying between 1.3 and 4.6 km and would encompass the start of the plunge region where matter begins to fall freely into the black hole.", "doi": "10.1093/mnras/staa564", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2020-04", "series_number": "4", "volume": "493", "issue": "4", "pages": "5389-5396" }, { "id": "authors:t49jt-5sd94", "collection": "authors", "collection_id": "t49jt-5sd94", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200414-104323467", "type": "article", "title": "The spin measurement of the black hole in 4U 1543-47 constrained with the X-ray reflected emission", "author": [ { "family_name": "Dong", "given_name": "Yanting", "clpid": "Dong-Yanting" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Steiner", "given_name": "James F.", "orcid": "0000-0002-5872-6061", "clpid": "Steiner-J-F" }, { "family_name": "Gou", "given_name": "Lijun", "clpid": "Gou-Lijun" } ], "abstract": "4U 1543-47 is a low-mass X-ray binary that harbours a stellar-mass black hole located in our Milky Way galaxy. In this paper, we revisit seven data sets that were in the Steep Power Law state of the 2002 outburst. The spectra were observed by the Rossi X-ray Timing Explorer. We have carefully modelled the X-ray reflection spectra and made a joint-fit to these spectra with relxill for the reflected emission. We found a moderate black hole spin, which is 0.67^(+0.15)_(\u22120.08) at 90 per\u2009cent statistical confidence. Negative and low spins (<0.5) at more than 99 per\u2009cent statistical confidence are ruled out. In addition, our results indicate that the model requires a supersolar iron abundance: 5.05^(+1.21)_(\u22120.26), and the inclination angle of the inner disc is 36.3^(+5.3)_(\u22123.4) deg. This inclination angle is appreciably larger than the binary orbital inclination angle (\u223c21 deg); this difference is possibly a systematic artefact of the artificially low density employed in the reflection model for this X-ray binary system.", "doi": "10.1093/mnras/staa606", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2020-04", "series_number": "3", "volume": "493", "issue": "3", "pages": "4409-4417" }, { "id": "authors:m4nw6-sj350", "collection": "authors", "collection_id": "m4nw6-sj350", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200327-150029432", "type": "article", "title": "Evidence for Returning Disk Radiation in the Black Hole X-Ray Binary XTE J1550\u2013564", "author": [ { "family_name": "Connors", "given_name": "Riley M. T.", "orcid": "0000-0002-8908-759X", "clpid": "Connors-R-M-T" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-T" }, { "family_name": "Grinberg", "given_name": "Victoria", "orcid": "0000-0003-2538-0188", "clpid": "Grinberg-V" }, { "family_name": "Steiner", "given_name": "James F.", "orcid": "0000-0002-5872-6061", "clpid": "Steiner-J-F" }, { "family_name": "Sridhar", "given_name": "Navin", "orcid": "0000-0002-5519-9550", "clpid": "Sridhar-N" }, { "family_name": "Wilms", "given_name": "J\u00f6rn", "orcid": "0000-0003-2065-5410", "clpid": "Wilms-J" }, { "family_name": "Tomsick", "given_name": "John", "orcid": "0000-0001-5506-9855", "clpid": "Tomsick-J-A" }, { "family_name": "Harrison", "given_name": "Fiona", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" }, { "family_name": "Licklederer", "given_name": "Stefan", "orcid": "0000-0002-3720-4408", "clpid": "Licklederer-S" } ], "abstract": "We explore the accretion properties of the black hole X-ray binary XTE J1550\u2212564 during its outbursts in 1998/99 and 2000. We model the disk, corona, and reflection components of X-ray spectra taken with the Rossi X-ray Timing Explorer, using the relxill suite of reflection models. The key result of our modeling is that the reflection spectrum in the very soft state is best explained by disk self-irradiation, i.e., photons from the inner disk are bent by the strong gravity of the black hole and reflected off the disk surface. This is the first known detection of thermal disk radiation reflecting off the inner disk. There is also an apparent absorption line at ~6.9 keV, which may be evidence of an ionized disk wind. The coronal electron temperature (kT_e) is, as expected, lower in the brighter outburst of 1998/99, explained qualitatively by more efficient coronal cooling due to irradiating disk photons. The disk inner radius is consistent with being within a few times the innermost stable circular orbit throughout the bright-hard-to-soft states (10 s of r_g in gravitational units). The disk inclination is low during the hard state, disagreeing with the binary inclination value, and very close to 90\u00b0 in the soft state, recovering to a lower value when adopting a blackbody spectrum as the irradiating continuum.", "doi": "10.3847/1538-4357/ab7afc", "issn": "1538-4357", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2020-03-20", "series_number": "1", "volume": "892", "issue": "1", "pages": "Art. No. 47" }, { "id": "authors:50z5b-nh090", "collection": "authors", "collection_id": "50z5b-nh090", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200310-133032776", "type": "article", "title": "Plasma-environment effects on K lines of astrophysical interest. III. IPs, K thresholds, radiative rates, and Auger widths in Fe\u202fIX \u2013 Fe\u202fXVI", "author": [ { "family_name": "Deprince", "given_name": "J.", "orcid": "0000-0002-3409-8232", "clpid": "Deprince-J\u00e9r\u00f4me" }, { "family_name": "Bautista", "given_name": "M. A.", "clpid": "Bautista-M-A" }, { "family_name": "Fritzsche", "given_name": "S.", "clpid": "Fritzsche-Stephan" }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Kallman", "given_name": "T. R.", "orcid": "0000-0002-5779-6906", "clpid": "Kallman-Timothy-R" }, { "family_name": "Mendoza", "given_name": "C.", "clpid": "Mendoza-C" }, { "family_name": "Palmeri", "given_name": "P.", "clpid": "Palmeri-P" }, { "family_name": "Quinet", "given_name": "P.", "clpid": "Quinet-P" } ], "abstract": "Aims. In the context of black-hole accretion disks, we aim to compute the plasma-environment effects on the atomic parameters used to model the decay of K-vacancy states in moderately charged iron ions, namely Fe\u202fIX \u2013 Fe\u202fXVI. \n\nMethods. We used the fully relativistic multiconfiguration Dirac\u2013Fock method approximating the plasma electron\u2013nucleus and electron\u2013electron screenings with a time-averaged Debye\u2013H\u00fcckel potential. \n\nResults. We report modified ionization potentials, K-threshold energies, wavelengths, radiative emission rates, and Auger widths for plasmas characterized by electron temperatures and densities in the ranges 10\u2075\u221210\u2077 K and 10\u00b9\u2078\u221210\u00b2\u00b2 cm\u207b\u00b3. \n\nConclusions. This study confirms that the high-resolution X-ray spectrometers onboard the future XRISM and Athena space missions will be capable of detecting the lowering of the K edges of these ions due to the extreme plasma conditions occurring in accretion disks around compact objects.", "doi": "10.1051/0004-6361/201937088", "issn": "0004-6361", "publisher": "EDP Sciences", "publication": "Astronomy and Astrophysics", "publication_date": "2020-03", "volume": "635", "pages": "Art. No. A70" }, { "id": "authors:n30ph-h2c71", "collection": "authors", "collection_id": "n30ph-h2c71", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200212-140525387", "type": "article", "title": "NuSTAR Observations of the Transient Galactic Black Hole Binary Candidate Swift J1858.6\u20130814: A New Sibling of V404 Cyg and V4641 Sgr?", "author": [ { "family_name": "Hare", "given_name": "Jeremy", "orcid": "0000-0002-8548-482X", "clpid": "Hare-J" }, { "family_name": "Tomsick", "given_name": "John A.", "orcid": "0000-0001-5506-9855", "clpid": "Tomsick-J-A" }, { "family_name": "Buisson", "given_name": "Douglas J. K.", "clpid": "Buisson-D-J-K" }, { "family_name": "Clavel", "given_name": "Ma\u00efca", "orcid": "0000-0003-0724-2742", "clpid": "Clavel-M" }, { "family_name": "Gandhi", "given_name": "Poshak", "orcid": "0000-0003-3105-2615", "clpid": "Gandhi-Poshak" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Grefenstette", "given_name": "Brian W.", "orcid": "0000-0002-1984-2932", "clpid": "Grefenstette-B-W" }, { "family_name": "Walton", "given_name": "Dominic J.", "orcid": "0000-0001-5819-3552", "clpid": "Walton-D-J" }, { "family_name": "Xu", "given_name": "Yanjun", "orcid": "0000-0003-2443-3698", "clpid": "Xu-Yanjun" } ], "abstract": "Swift J1858.6\u22120814 was discovered by the Burst Alert Telescope on Swift on 2018 October 25. Here we report on the first follow-up Nuclear Spectroscopic Telescope Array (NuSTAR) observation of the source, which shows variability spanning two orders of magnitude in count rate on timescales of ~10\u2013100 s. The power spectrum of the source does not show any quasi-periodic oscillations or periodicity, but has a large fractional rms amplitude of 147% \u00b1 3%, exhibiting a number of large flares throughout the observation. The hardness ratio (defined as R_(10\u201379keV)/R_(3\u201310keV)) of the flares tends to be soft, while the source spans a range of hardness ratios during nonflaring periods. The X-ray spectrum of the source shows strong reflection features, which become more narrow and peaked during the nonflaring intervals. We fit an absorbed relativistic reflection model to the source spectra to place physical constraints on the system. Most notably, we find that the source exhibits a large and varying intrinsic absorbing column density (N_H = (1.4\u20134.2) \u00d7 10\u00b2\u00b3 cm\u207b\u00b2). This large intrinsic absorption is further supported by the energy spectra extracted from two flares observed simultaneously by NuSTAR and the Neutron Star Interior Composition Explorer. We find that the inner accretion disk of the source has a low inclination, I < 29\u2218 (3\u03c3 upper limit), while the iron abundance in the disk is close to solar, A_(Fe) = 1.0 \u00b1 0.3. We set a 90% confidence upper limit on the inner radius of the accretion disk of r_(in) < 8r_(ISCO) and, by fixing r_(in) to be at r_(ISCO), a 90% confidence lower limit on the spin of the black hole of a\u2217 > 0.0. Finally, we compare the properties of Swift J1858.6\u22120814 to those of V404 Cygni and V4641 Sgr, which both show rapid flaring and a strong and variable absorption.", "doi": "10.3847/1538-4357/ab6a12", "issn": "1538-4357", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2020-02-10", "series_number": "1", "volume": "890", "issue": "1", "pages": "Art. No. 57" }, { "id": "authors:a9c0e-j1d30", "collection": "authors", "collection_id": "a9c0e-j1d30", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200212-134110015", "type": "article", "title": "Evolution of the Accretion Disk\u2013Corona during the Bright Hard-to-soft State Transition: A Reflection Spectroscopic Study with GX 339\u20134", "author": [ { "family_name": "Sridhar", "given_name": "Navin", "orcid": "0000-0002-5519-9550", "clpid": "Sridhar-Navin" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Steiner", "given_name": "James F.", "orcid": "0000-0002-5872-6061", "clpid": "Steiner-James-F" }, { "family_name": "Connors", "given_name": "Riley M. T.", "orcid": "0000-0002-8908-759X", "clpid": "Connors-Riley-M-T" }, { "family_name": "Grinberg", "given_name": "Victoria", "orcid": "0000-0003-2538-0188", "clpid": "Grinberg-Victoria" }, { "family_name": "Harrison", "given_name": "Fiona A.", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" } ], "abstract": "We present the analysis of several observations of the black hole binary GX 339\u20134 during its bright intermediate states from two different outbursts (2002 and 2004), as observed by the RXTE/Proportional Counter Array. We perform a consistent study of its reflection spectrum by employing the RELXILL family of relativistic reflection models to probe the evolutionary properties of the accretion disk including the inner disk radius (R_(in)), ionization parameter (\u03be), temperatures of the inner disk (T_(in)), corona (kT_e), and its optical depth (\u03c4). Our analysis indicates that the disk inner edge approaches the innermost stable circular orbit during the early onset of the bright hard state, and that the truncation radius of the disk remains low (<9 R_g) throughout the transition from hard to soft state. This suggests that the changes observed in the accretion disk properties during the state transition are driven by variation in accretion rate, and not necessarily due to changes in the inner disk's radius. We compare the aforementioned disk properties in two different outbursts with state transitions occurring at dissimilar luminosities and find identical evolutionary trends in the disk properties, with differences only seen in the corona's kT_e and \u03c4. We also perform an analysis by employing a self-consistent Comptonized accretion disk model accounting for the scatter of disk photons by the corona, and measure the low inner disk truncation radius across the bright intermediate states, using the temperature-dependent values of the spectral hardening factor, thereby independently confirming our results from the reflection analysis.", "doi": "10.3847/1538-4357/ab64f5", "issn": "1538-4357", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2020-02-10", "series_number": "1", "volume": "890", "issue": "1", "pages": "Art. No. 53" }, { "id": "authors:b70a4-k5611", "collection": "authors", "collection_id": "b70a4-k5611", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190422-091140727", "type": "article", "title": "K\u2010line X\u2010ray fluorescence from highly charged iron ions under dense astrophysical plasma conditions", "author": [ { "family_name": "Deprince", "given_name": "J\u00e9r\u00f4me", "orcid": "0000-0002-3409-8232", "clpid": "Deprince-J\u00e9r\u00f4me" }, { "family_name": "Bautista", "given_name": "Manuel", "clpid": "Bautista-Manuel" }, { "family_name": "Fritzsche", "given_name": "Stephan", "clpid": "Fritzsche-Stephan" }, { "family_name": "Garc\u00eda", "given_name": "Javier", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Kallman", "given_name": "Timothy", "orcid": "0000-0002-5779-6906", "clpid": "Kallman-Timothy-R" }, { "family_name": "Mendoza", "given_name": "Claudio", "clpid": "Mendoza-C" }, { "family_name": "Palmeri", "given_name": "Patrick", "clpid": "Palmeri-P" }, { "family_name": "Quinet", "given_name": "Pascal", "clpid": "Quinet-P" } ], "abstract": "In the present work, we report an investigation of plasma environment effects on the atomic parameters associated with the K\u2010vacancy states in highly charged iron ions within the astrophysical context of accretion disks around black holes. More particularly, the sensitivity of K\u2010line X\u2010ray fluorescence parameters (wavelengths, radiative transition probabilities, and Auger rates) in Fe XVII\u2013Fe XXV ions has been estimated for plasma conditions characterized by an electron temperature ranging from 10\u2075 to 10\u2077 K and an electron density ranging from 10\u00b9\u2078 to 10\u00b2\u00b2 cm\u207b\u00b3. In order to do this, relativistic multiconfiguration Dirac\u2010Fock atomic structure calculations have been carried out by considering a time averaged Debye\u2010H\u00fcckel potential for both the electron\u2013nucleus and electron\u2013electron interactions.", "doi": "10.1002/xrs.3040", "issn": "0049-8246", "publisher": "Wiley", "publication": "X-Ray Spectrometry", "publication_date": "2020-02", "series_number": "1", "volume": "49", "issue": "1", "pages": "29-32" }, { "id": "authors:tgyhj-1tg34", "collection": "authors", "collection_id": "tgyhj-1tg34", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190809-154849136", "type": "article", "title": "The 2017 Failed Outburst of GX 339-4: Relativistic X-ray Reflection near the Black Hole Revealed by NuSTAR and Swift Spectroscopy", "author": [ { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Tomsick", "given_name": "John A.", "orcid": "0000-0001-5506-9855", "clpid": "Tomsick-J-A" }, { "family_name": "Sridhar", "given_name": "Navin", "orcid": "0000-0002-5519-9550", "clpid": "Sridhar-N" }, { "family_name": "Grinberg", "given_name": "Victoria", "orcid": "0000-0003-2538-0188", "clpid": "Grinberg-V" }, { "family_name": "Connors", "given_name": "Riley M. T.", "orcid": "0000-0002-8908-759X", "clpid": "Connors-R-M-T" }, { "family_name": "Wang", "given_name": "Jingyi", "orcid": "0000-0002-1742-2125", "clpid": "Wang-Jingyi" }, { "family_name": "Steiner", "given_name": "James F.", "orcid": "0000-0002-5872-6061", "clpid": "Steiner-J-F" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-T" }, { "family_name": "Walton", "given_name": "Dominic J.", "orcid": "0000-0001-5819-3552", "clpid": "Walton-D-J" }, { "family_name": "Xu", "given_name": "Yanjun", "orcid": "0000-0003-2443-3698", "clpid": "Xu-Yanjun" }, { "family_name": "Harrison", "given_name": "Fiona A.", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" }, { "family_name": "Foster", "given_name": "Karl", "orcid": "0000-0001-5800-5531", "clpid": "Forster-K" }, { "family_name": "Grefenstette", "given_name": "Brian", "orcid": "0000-0002-1984-2932", "clpid": "Grefenstette-B-W" }, { "family_name": "Madsen", "given_name": "Kristin", "orcid": "0000-0003-1252-4891", "clpid": "Madsen-K-K" }, { "family_name": "Fabian", "given_name": "Andrew", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-A-C" } ], "abstract": "We report on the spectroscopic analysis of the black hole binary GX 339\u22124 during its recent 2017\u20132018 outburst, observed simultaneously by the Swift and NuSTAR observatories. Although during this particular outburst the source failed to make state transitions, and despite Sun constraints during the peak luminosity, we were able to trigger four different observations sampling the evolution of the source in the hard state. We show that even for the lowest-luminosity observations the NuSTAR spectra show clear signatures of X-ray reprocessing (reflection) in an accretion disk. Detailed analysis of the highest signal-to-noise spectra with our family of relativistic reflection models RELXILL indicates the presence of both broad and narrow reflection components. We find that a dual-lamppost model provides a superior fit when compared to the standard single lamppost plus distant neutral reflection. In the dual-lamppost model two sources at different heights are placed on the rotational axis of the black hole, suggesting that the narrow component of the Fe K emission is likely to originate in regions far away in the disk, but still significantly affected by its rotational motions. Regardless of the geometry assumed, we find that the inner edge of the accretion disk reaches a few gravitational radii in all our fits, consistent with previous determinations at similar luminosity levels. This confirms a very low degree of disk truncation for this source at luminosities above ~1% Eddington. Our estimates of R_(in) reinforce the suggested behavior for an inner disk that approaches the innermost regions as the luminosity increases in the hard state.", "doi": "10.3847/1538-4357/ab384f", "issn": "1538-4357", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2019-11-01", "series_number": "1", "volume": "885", "issue": "1", "pages": "Art. No. 48" }, { "id": "authors:0ttqx-46f85", "collection": "authors", "collection_id": "0ttqx-46f85", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191007-153821692", "type": "article", "title": "High Density Reflection Spectroscopy \u2013 II. The density of the inner black hole accretion disc in AGN", "author": [ { "family_name": "Jiang", "given_name": "Jiachen", "orcid": "0000-0002-9639-4352", "clpid": "Jiang-Jiachen" }, { "family_name": "Fabian", "given_name": "Andrew C.", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-A-C" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-T" }, { "family_name": "Gallo", "given_name": "Luigi", "clpid": "Gallo-L-C" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Kara", "given_name": "Erin", "orcid": "0000-0003-0172-0854", "clpid": "Kara-E" }, { "family_name": "Parker", "given_name": "Michael L.", "orcid": "0000-0002-8466-7317", "clpid": "Parker-M-L" }, { "family_name": "Tomsick", "given_name": "John A.", "orcid": "0000-0001-5506-9855", "clpid": "Tomsick-J-A" }, { "family_name": "Walton", "given_name": "Dominic J.", "orcid": "0000-0001-5819-3552", "clpid": "Walton-D-J" }, { "family_name": "Reynolds", "given_name": "Christopher S.", "clpid": "Reynolds-C-S" } ], "abstract": "We present a high density disc reflection spectral analysis of a sample of 17 Seyfert 1 galaxies to study the inner disc densities at different black hole mass scales and accretion rates. All the available XMM\u2013Newton observations in the archive are used. OM observations in the optical/UV band are used to estimate their accretion rates. We find that 65 per cent of sources in our sample show a disc density significantly higher than n_e = 10^(15)\u2009cm^(\u22123), which was assumed in previous reflection-based spectral analyses. The best-fitting disc densities show an anticorrelation with black hole mass and mass accretion rate. High density disc reflection model can successfully explain the soft excess emission and significantly reduce inferred iron abundances. We also compare our black hole spin and disc inclination angle measurements with previous analyses.", "doi": "10.1093/mnras/stz2326", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2019-11", "series_number": "3", "volume": "489", "issue": "3", "pages": "3436-3455" }, { "id": "authors:m6355-zdn43", "collection": "authors", "collection_id": "m6355-zdn43", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190917-134739032", "type": "article", "title": "MAXI J1820+070 with NuSTAR I. An increase in variability frequency but a stable reflection spectrum: coronal properties and implications for the inner disc in black hole binaries", "author": [ { "family_name": "Buisson", "given_name": "D. J. K.", "clpid": "Buisson-D-J-K" }, { "family_name": "Fabian", "given_name": "A. C.", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-A-C" }, { "family_name": "Barret", "given_name": "D.", "orcid": "0000-0002-0393-9190", "clpid": "Barret-D" }, { "family_name": "F\u00fcrst", "given_name": "F.", "orcid": "0000-0003-0388-0560", "clpid": "F\u00fcrst-F" }, { "family_name": "Gandhi", "given_name": "P.", "orcid": "0000-0003-3105-2615", "clpid": "Gandhi-Poshak" }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Kara", "given_name": "E.", "orcid": "0000-0003-0172-0854", "clpid": "Kara-E" }, { "family_name": "Madsen", "given_name": "K. K.", "orcid": "0000-0003-1252-4891", "clpid": "Madsen-K-K" }, { "family_name": "Miller", "given_name": "J. M.", "clpid": "Miller-J-M" }, { "family_name": "Parker", "given_name": "M. L.", "orcid": "0000-0002-8466-7317", "clpid": "Parker-M-L" }, { "family_name": "Shaw", "given_name": "A. W.", "clpid": "Shaw-A-W" }, { "family_name": "Tomsick", "given_name": "J. A.", "orcid": "0000-0001-5506-9855", "clpid": "Tomsick-J-A" }, { "family_name": "Walton", "given_name": "D. J.", "orcid": "0000-0001-5819-3552", "clpid": "Walton-D-J" } ], "abstract": "MAXI J1820+070 (optical counterpart ASASSN-18ey) is a black hole candidate discovered through its recent very bright outburst. The low extinction column and long duration at high flux allow detailed measurements of the accretion process to be made. In this work, we compare the evolution of X-ray spectral and timing properties through the initial hard state of the outburst. We show that the inner accretion disc, as measured by relativistic reflection, remains steady throughout this period of the outburst. Nevertheless, subtle spectral variability is observed, which is well explained by a change in coronal geometry. However, characteristic features of the temporal variability \u2013 low-frequency roll-over and quasi-periodic oscillation frequency \u2013 increase drastically in frequency, as the outburst proceeds. This suggests that the variability time-scales are governed by coronal conditions rather than solely by the inner disc radius. We also find a strong correlation between X-ray luminosity and coronal temperature. This can be explained by electron pair production with a changing effective radius and a non-thermal electron fraction of \u223c20 per\u2009cent.", "doi": "10.1093/mnras/stz2681", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2019-11", "series_number": "1", "volume": "490", "issue": "1", "pages": "1350-1362" }, { "id": "authors:7v82e-sn797", "collection": "authors", "collection_id": "7v82e-sn797", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191120-082655287", "type": "article", "title": "New Tools for Self-consistent Modeling of the AGN Torus and Corona", "author": [ { "family_name": "Balokovi\u0107", "given_name": "Mislav", "orcid": "0000-0003-0476-6647", "clpid": "Balokovi\u0107-M" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Cabral", "given_name": "Samantha E.", "clpid": "Cabral-S-E" } ], "abstract": "The continuum emission typically observed in the X-ray spectra of active galactic nuclei (AGNs) is thought to arise from inverse-Compton scattering of blackbody photons from the accretion disk by mildly relativistic thermal electrons in a rarefied and relatively hotter corona. By fitting theoretical spectral models (e.g., Poutanen & Svensson 1996; Coppi 1999) to the observed shape of an AGN coronal continuum it is possible to constrain some of its physical parameters, such as the electron temperature and optical depth (e.g., Fabian et al. 2015; Middei et al. 2019).", "doi": "10.3847/2515-5172/ab578e", "issn": "2515-5172", "publisher": "American Astronomical Society", "publication": "Research Notes of the AAS", "publication_date": "2019-11", "series_number": "11", "volume": "3", "issue": "11", "pages": "Art. No. 173" }, { "id": "authors:11zpx-6pm87", "collection": "authors", "collection_id": "11zpx-6pm87", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191115-140244763", "type": "article", "title": "Swift-XRT Follow-up of Gravitational-wave Triggers in the Second Advanced LIGO/Virgo Observing Run", "author": [ { "family_name": "Klingler", "given_name": "N. J.", "orcid": "0000-0002-7465-0941", "clpid": "Klingler-N-J" }, { "family_name": "Garc\u00eda", "given_name": "J.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" } ], "abstract": "The Neil Gehrels Swift Observatory carried out prompt searches for gravitational-wave (GW) events detected by the LIGO/Virgo Collaboration (LVC) during the second observing run (\"O2\"). Swift performed extensive tiling of eight LVC triggers, two of which had very low false-alarm rates (GW170814 and the epochal GW170817), indicating a high confidence of being astrophysical in origin; the latter was the first GW event to have an electromagnetic counterpart detected. In this paper we describe the follow-up performed during O2 and the results of our searches. No GW electromagnetic counterparts were detected; this result is expected, as GW170817 remained the only astrophysical event containing at least one neutron star after LVC's later retraction of some events. A number of X-ray sources were detected, with the majority of identified sources being active galactic nuclei. We discuss the detection rate of transient X-ray sources and their implications in the O2 tiling searches. Finally, we describe the lessons learned during O2 and how these are being used to improve the Swift follow-up of GW events. In particular, we simulate a population of gamma-ray burst afterglows to evaluate our source ranking system's ability to differentiate them from unrelated and uncataloged X-ray sources. We find that \u224860%\u201370% of afterglows whose jets are oriented toward Earth will be given high rank (i.e., \"interesting\" designation) by the completion of our second follow-up phase (assuming that their location in the sky was observed), but that this fraction can be increased to nearly 100% by performing a third follow-up observation of sources exhibiting fading behavior.", "doi": "10.3847/1538-4365/ab4ea2", "issn": "1538-4365", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal Supplement Series", "publication_date": "2019-11", "series_number": "1", "volume": "245", "issue": "1", "pages": "Art. No. 15" }, { "id": "authors:9b3bb-dny67", "collection": "authors", "collection_id": "9b3bb-dny67", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190918-140450734", "type": "article", "title": "Observations of the Ultra-compact X-Ray Binary 4U 1543-624 in Outburst with NICER, INTEGRAL, Swift, and ATCA", "author": [ { "family_name": "Ludlam", "given_name": "R. M.", "orcid": "0000-0002-8961-939X", "clpid": "Ludlam-R-M" }, { "family_name": "Shishkovsky", "given_name": "L.", "clpid": "Shishkovsky-L" }, { "family_name": "Bult", "given_name": "P. M.", "clpid": "Bult-P-M" }, { "family_name": "Miller", "given_name": "J. M.", "clpid": "Miller-J-M" }, { "family_name": "Zoghbi", "given_name": "A.", "orcid": "0000-0002-0572-9613", "clpid": "Zoghbi-A" }, { "family_name": "Strohmayer", "given_name": "T. E.", "orcid": "0000-0001-7681-5845", "clpid": "Strohmayer-T-E" }, { "family_name": "Reynolds", "given_name": "M.", "clpid": "Reynolds-M-T" }, { "family_name": "Natalucci", "given_name": "L.", "orcid": "0000-0002-6601-9543", "clpid": "Natalucci-L" }, { "family_name": "Miller-Jones", "given_name": "J. C. A.", "orcid": "0000-0003-3124-2814", "clpid": "Miller-Jones-J-C-A" }, { "family_name": "Jaisawal", "given_name": "G. K.", "orcid": "0000-0002-6789-2723", "clpid": "Jaisawal-G-K" }, { "family_name": "Guillot", "given_name": "S.", "orcid": "0000-0002-6449-106X", "clpid": "Guillot-S" }, { "family_name": "Gendreau", "given_name": "K. C.", "clpid": "Gendreau-K-C" }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Fiocchi", "given_name": "M.", "orcid": "0000-0001-5697-6019", "clpid": "Fiocchi-M" }, { "family_name": "Fabian", "given_name": "A. C.", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-A-C" }, { "family_name": "Chakrabarty", "given_name": "D.", "orcid": "0000-0001-8804-8946", "clpid": "Chakrabarty-D" }, { "family_name": "Cackett", "given_name": "E. M.", "orcid": "0000-0002-8294-9281", "clpid": "Cackett-E-M" }, { "family_name": "Bahramian", "given_name": "A.", "orcid": "0000-0003-2506-6041", "clpid": "Bahramian-A" }, { "family_name": "Arzoumanian", "given_name": "Z.", "clpid": "Arzoumanian-Z" }, { "family_name": "Altamirano", "given_name": "D.", "orcid": "0000-0002-3422-0074", "clpid": "Altamirano-D" } ], "abstract": "We report on X-ray and radio observations of the ultra-compact X-ray binary 4U 1543\u2212624 taken in August 2017 during an enhanced accretion episode. We obtained Neutron Star Interior Composition Explorer (NICER) monitoring of the source over a ~10 day period during which target-of-opportunity observations were also conducted with Swift, INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL), and the Australia Telescope Compact Array. Emission lines were measured in the NICER X-ray spectrum at ~0.64 keV and ~6.4 keV that correspond to O and Fe, respectively. By modeling these line components, we are able to track changes in the accretion disk throughout this period. The innermost accretion flow appears to move inwards from hundreds of gravitational radii (R_g = GM/c^2) at the beginning of the outburst to <8.7 R g at peak intensity. We do not detect the source in radio, but are able to place a 3\u03c3 upper limit on the flux density at 27 \u03bcJy beam^(\u22121). Comparing the radio and X-ray luminosities, we find that the source lies significantly away from the range typical of black holes in the L_r-L_x plane, suggesting a neutron star primary. This adds to the evidence that neutron stars (NSs) do not follow a single track in the L_r-L_x plane, limiting its use in distinguishing between different classes of NSs based on radio and X-ray observations alone.", "doi": "10.3847/1538-4357/ab3806", "issn": "1538-4357", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2019-09-20", "series_number": "1", "volume": "883", "issue": "1", "pages": "Art. No. 39" }, { "id": "authors:0be4w-vzp04", "collection": "authors", "collection_id": "0be4w-vzp04", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190916-143938315", "type": "article", "title": "Conflicting Disk Inclination Estimates for the Black Hole X-Ray Binary XTE J1500\u2212564", "author": [ { "family_name": "Connors", "given_name": "Riley M. T.", "orcid": "0000-0002-8908-759X", "clpid": "Connors-R-M-T" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Steiner", "given_name": "James F.", "orcid": "0000-0002-5872-6061", "clpid": "Steiner-J-F" }, { "family_name": "Grinberg", "given_name": "Victoria", "orcid": "0000-0003-2538-0188", "clpid": "Grinberg-V" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-T" }, { "family_name": "Sridhar", "given_name": "Navin", "orcid": "0000-0002-5519-9550", "clpid": "Sridhar-N" }, { "family_name": "Gatuzz", "given_name": "Efrain", "orcid": "0000-0002-3252-9633", "clpid": "Gatuzz-E" }, { "family_name": "Tomsick", "given_name": "John", "orcid": "0000-0001-5506-9855", "clpid": "Tomsick-J-A" }, { "family_name": "Markoff", "given_name": "Sera B.", "orcid": "0000-0001-9564-0876", "clpid": "Markoff-S-B" }, { "family_name": "Harrison", "given_name": "Fiona", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" } ], "abstract": "The dynamical characteristics of XTE J1550\u2212564, a black hole X-ray binary, are well established, and the broadband spectral evolution of the source has been well studied. Its orbital inclination is known to be high, at ~75\u00b0, with the jet estimated to align well with the orbital axis. We explore simultaneous observations made with the Advanced Satellite for Cosmology and Astrophysics and Rossi X-ray Timing Explorer covering the 1\u2013200 keV band during the early stages of the first outburst of XTE J1550\u2212564 in its hard-intermediate state on 1998 September 23/24. We show that the most up-to-date reflection models applied to these data yield an inclination estimate much lower than that found in previous studies at ~40\u00b0, grossly disagreeing with the dynamically estimated orbital inclination. We discuss the possible explanations for this disagreement and its implications for reflection models, including possible physical scenarios in which either the inner disk is misaligned with both the binary orbit and the outer jet or the inner accretion flow, corona, and/or jet have vertical structure that leads to lower inferred disk inclination through various physical means.", "doi": "10.3847/1538-4357/ab35df", "issn": "1538-4357", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2019-09-10", "series_number": "2", "volume": "882", "issue": "2", "pages": "Art. No. 179" }, { "id": "authors:5c2nw-j6n61", "collection": "authors", "collection_id": "5c2nw-j6n61", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190926-144904972", "type": "article", "title": "A public relativistic transfer function model for X-ray reverberation mapping of accreting black holes", "author": [ { "family_name": "Ingram", "given_name": "Adam", "orcid": "0000-0002-5311-9078", "clpid": "Ingram-A" }, { "family_name": "Mastroserio", "given_name": "Guglielmo", "clpid": "Mastroserio-G" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-T" }, { "family_name": "Hovenkamp", "given_name": "Pieter", "clpid": "Hovenkamp-P" }, { "family_name": "van\u00a0der\u00a0Klis", "given_name": "Michiel", "orcid": "0000-0003-0070-9872", "clpid": "van-der-Klis-M" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" } ], "abstract": "We present the publicly available model RELTRANS that calculates the light-crossing delays and energy shifts experienced by X-ray photons originally emitted close to the black hole when they reflect from the accretion disc and are scattered into our line of sight, accounting for all general relativistic effects. Our model is fast and flexible enough to be simultaneously fit to the observed energy-dependent cross-spectrum for a large range of Fourier frequencies, as well as to the time-averaged spectrum. This not only enables better geometric constraints than only modelling the relativistically broadened reflection features in the time-averaged spectrum, but additionally enables constraints on the mass of supermassive black holes in active galactic nuclei and stellar-mass black holes in X-ray binaries. We include a self-consistently calculated radial profile of the disc ionization parameter and properly account for the effect that the telescope response has on the predicted time lags. We find that a number of previous spectral analyses have measured artificially low source heights due to not accounting for the former effect and that timing analyses have been affected by the latter. In particular, the magnitude of the soft lags in active galactic nuclei may have been underestimated, and the magnitude of lags attributed to thermal reverberation in X-ray binaries may have been overestimated. We fit RELTRANS to the lag-energy spectrum of the Seyfert galaxy Mrk 335, resulting in a best-fitting black hole mass that is smaller than previous optical reverberation measurements (\u223c7 million compared with \u223c14\u201326 million M\u2299).", "doi": "10.1093/mnras/stz1720", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2019-09", "series_number": "1", "volume": "488", "issue": "1", "pages": "324-347" }, { "id": "authors:gntgc-q8p32", "collection": "authors", "collection_id": "gntgc-q8p32", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190816-075233072", "type": "article", "title": "Re-awakening of GRS 1716\u2013249 after 23\u00a0yr, observed by Swift/XRT and NuSTAR", "author": [ { "family_name": "Bharali", "given_name": "Priya", "clpid": "Bharali-P" }, { "family_name": "Chandra", "given_name": "Sunil", "orcid": "0000-0002-8776-1835", "clpid": "Chandra-S" }, { "family_name": "Chauhan", "given_name": "Jaiverdhan", "orcid": "0000-0003-0330-1901", "clpid": "Chauhan-J" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Roy", "given_name": "Jayashree", "orcid": "0000-0002-2329-5863", "clpid": "Roy-J" }, { "family_name": "Boettcher", "given_name": "Markus", "clpid": "Boettcher-M" }, { "family_name": "Boruah", "given_name": "Kalyanee", "clpid": "Boruah-K" } ], "abstract": "In this work, we present a spectral and temporal analysis of Swift/XRT and NuSTAR observations of GRS 1716\u2013249 during its recent 2016\u20132017 outburst. This low-mass X-ray binary underwent an extraordinary outburst after a long quiescence of 23 yr, since its last major outburst in 1993. The source was observed over two different epochs during 2017 April 7 and 10. The best-fitting joint spectral fitting in the energy range 0.5\u201379.0 keV indicates that the spectrum is best described by relatively cold, weak disc blackbody emission, dominant thermal Comptonization emission, and a relativistically broadened fluorescent iron K \u03b1 emission line. We observed a clear indication of a Compton hump around 30 keV. We also detected an excess feature of 1.3 keV. Assuming a lamp-post geometry of the corona, we constrained the inner disc radius for both observations to 11.92^(+8.62)_(\u221211.92) R_(ISCO) (i.e. an upper limit) and 10.39^(+9.51)_(\u22123.02) R_(ISCO)(where R_(ISCO) \u2261 radius of the innermost stable circular orbit) for the first epoch (E1) and second epoch (E2), respectively. A significant (5\u03c3) type C quasi-periodic oscillation (QPO) at 1.20 \u00b1 0.04 Hz is detected for the first time for GRS 1716\u2013249, which drifts to 1.55 \u00b1 0.04 Hz (6\u03c3) at the end of the second observation. The derived spectral and temporal properties show a positive correlation between the QPO frequency and the photon index.", "doi": "10.1093/mnras/stz1492", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2019-08", "series_number": "3", "volume": "487", "issue": "3", "pages": "3150-3161" }, { "id": "authors:mma52-scc20", "collection": "authors", "collection_id": "mma52-scc20", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20181008-140935194", "type": "article", "title": "Testing the Kerr metric with X-ray Reflection Spectroscopy of Mrk 335 Suzaku data", "author": [ { "family_name": "Choudhury", "given_name": "Kishalay", "clpid": "Choudhury-K" }, { "family_name": "Nampalliwar", "given_name": "Sourabh", "clpid": "Nampalliwar-S" }, { "family_name": "Abdikamalov", "given_name": "Askar B.", "clpid": "Abdikamalov-A-B" }, { "family_name": "Ayzenberg", "given_name": "Dimitry", "clpid": "Ayzenberg-D" }, { "family_name": "Bambi", "given_name": "Cosimo", "orcid": "0000-0002-3180-9502", "clpid": "Bambi-C" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-T" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" } ], "abstract": "Einstein's gravity has undergone extensive tests in the weak field gravitational limit, with results in agreement with theoretical predictions. There exist theories beyond general relativity (GR) which modify gravity in the strong field regime but agree with GR in the weak field. Astrophysical black holes are believed to be described by the Kerr metric and serve as suitable candidates to test strong gravity with electromagnetic radiation. We perform such a test by fitting one Suzaku data set of the narrow-line Seyfert 1 (NLS1) galaxy Mrk 335 with X-ray reflection spectroscopy, using the Johannsen metric to model the black hole spacetime and test for deviations from Kerr. We find the data is best modeled with a hybrid model that includes both partial covering absorption and a reflection component. This is the first time such a model has been proposed for a high-flux (low reflection) Mrk 335 data set. We constrain the Johannsen deformation parameter \u03b1_(13) to \u22121.5 < \u03b1_(13) < 0.6 with spin parameter a* > 0.8, and the \u03b1_(22) parameter to \u22120.4 < \u03b1_(22) < 2.1 with a* > 0.7, both at the 99% confidence level. Although additional solutions at large deviations from the Kerr metric show statistical similarity with the ones above, further analysis suggests these solutions may be manifestations of uncertainties beyond our control and do not represent the data. Hence, our results are in agreement with the idea that the supermassive compact object at the center of Mrk 335 is described by the Kerr metric.", "doi": "10.3847/1538-4357/ab24d6", "issn": "1538-4357", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2019-07-10", "series_number": "2", "volume": "879", "issue": "2", "pages": "Art. No. 80" }, { "id": "authors:3cqeg-yq742", "collection": "authors", "collection_id": "3cqeg-yq742", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190619-085644567", "type": "article", "title": "Broadband X-ray Spectral and Timing Analyses of the Black Hole Binary Candidate Swift J1658.2-4242: Rapid Flux Variation and the Turn-on of a Transient QPO", "author": [ { "family_name": "Xu", "given_name": "Yanjun", "orcid": "0000-0003-2443-3698", "clpid": "Xu-Yanjun" }, { "family_name": "Harrison", "given_name": "Fiona A.", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" }, { "family_name": "Tomsick", "given_name": "John A.", "orcid": "0000-0001-5506-9855", "clpid": "Tomsick-J-A" }, { "family_name": "Barret", "given_name": "Didier", "orcid": "0000-0002-0393-9190", "clpid": "Barret-D" }, { "family_name": "Gandhi", "given_name": "Poshak", "orcid": "0000-0003-3105-2615", "clpid": "Gandhi-Poshak" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Miller", "given_name": "Jon M.", "clpid": "Miller-J-M" }, { "family_name": "Uttley", "given_name": "Phil", "clpid": "Uttley-P" }, { "family_name": "Walton", "given_name": "Dominic J.", "orcid": "0000-0001-5819-3552", "clpid": "Walton-D-J" } ], "abstract": "We report results from joint Nuclear Spectroscopic Telescope Array, Swift, and XMM-Newton observations of the newly discovered black hole X-ray binary candidate Swift J1658.2\u20134242 in the intermediate state. We observe a peculiar event in this source, with its X-ray flux rapidly decreasing by ~45% in ~40 s, accompanied by only subtle changes in the shape of the broadband X-ray spectrum. In addition, we find a sudden turn-on of a transient quasi-periodic oscillation (QPO) with a frequency of 6\u20137 Hz around the time of the flux change, and the total fractional rms amplitude of the power spectrum increases from ~2% to ~10%. The X-ray spectral and timing analyses indicate that the flux decrease is driven by intrinsic changes in the accretion flow around the black hole, rather than intervening material along the line of sight. In addition, we do not significantly detect any relativistic disk reflection component, indicating it is much weaker than previously observed while the source was in the bright hard state. We propose accretion disk instabilities triggered at a large disk radius as the origin of the fast transition in spectral and timing properties, and discuss possible causes of the unusual properties observed in Swift J1658.2\u20134242. The prompt flux variation detected along with the emergence of a QPO makes the event an interesting case for investigating QPO mechanisms in black hole X-ray binaries.", "doi": "10.3847/1538-4357/ab24bf", "issn": "1538-4357", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2019-07-10", "series_number": "2", "volume": "879", "issue": "2", "pages": "Art. No. 93" }, { "id": "authors:q95p6-31e76", "collection": "authors", "collection_id": "q95p6-31e76", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190618-104022523", "type": "article", "title": "Public Release of RELXILL_NK: A Relativistic Reflection Model for Testing Einstein's Gravity", "author": [ { "family_name": "Abdikamalov", "given_name": "Askar B.", "clpid": "Abdikamalov-A-B" }, { "family_name": "Ayzenberg", "given_name": "Dimitry", "clpid": "Ayzenberg-D" }, { "family_name": "Bambi", "given_name": "Cosimo", "orcid": "0000-0002-3180-9502", "clpid": "Bambi-C" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-T" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Nampalliwar", "given_name": "Sourabh", "clpid": "Nampalliwar-S" } ], "abstract": "We present the public release version of relxill_nk, an X-ray reflection model for testing the Kerr hypothesis and general relativity. This model extends the relxill model that assumes the black hole (BH) spacetime is described by the Kerr metric. We also present relxilllp_nk, the first non-Kerr X-ray reflection model with a lamppost corona configuration, as well as all other models available in the full relxill_nk package. In all models the relevant relativistic effects are calculated through a general relativistic ray-tracing code that can be applied to any well-behaved, stationary, axisymmetric, and asymptotically flat BH spacetime. We show that the numerical error introduced by using a ray-tracing code is not significant compared with the observational error present in current X-ray reflection spectrum observations. In addition, we present the reflection spectrum for the Johannsen metric as calculated by relxill_nk.", "doi": "10.3847/1538-4357/ab1f89", "issn": "1538-4357", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2019-06-20", "series_number": "2", "volume": "878", "issue": "2", "pages": "Art. No. 91" }, { "id": "authors:z3kwe-azj32", "collection": "authors", "collection_id": "z3kwe-azj32", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190611-092516240", "type": "article", "title": "Testing the Kerr hypothesis using x-ray reflection spectroscopy with NuSTAR data of Cygnus X-1 in the soft state", "author": [ { "family_name": "Liu", "given_name": "Honghui", "clpid": "Liu-Honghui" }, { "family_name": "Abdikamalov", "given_name": "Askar B.", "clpid": "Abdikamalov-A-B" }, { "family_name": "Ayzenberg", "given_name": "Dimitry", "clpid": "Ayzenberg-D" }, { "family_name": "Bambi", "given_name": "Cosimo", "orcid": "0000-0002-3180-9502", "clpid": "Bambi-C" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-T" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Nampalliwar", "given_name": "Sourabh", "clpid": "Nampalliwar-S" } ], "abstract": "We continue exploring the constraining capabilities of x-ray reflection spectroscopy to test the Kerr-nature of astrophysical black holes, and we present the results of our analysis of two NuSTAR observations of Cygnus X-1 in the soft state. We find that the final measurement can strongly depend on the assumption of the intensity profile. We conclude that Cygnus X-1 is not suitable for tests of general relativity using x-ray reflection spectroscopy, and we discuss the desired properties of a source to be a good candidate for our studies.", "doi": "10.1103/PhysRevD.99.123007", "issn": "2470-0010", "publisher": "American Physical Society", "publication": "Physical Review D", "publication_date": "2019-06-15", "series_number": "12", "volume": "99", "issue": "12", "pages": "Art. No. 123007" }, { "id": "authors:vm3t2-7sh29", "collection": "authors", "collection_id": "vm3t2-7sh29", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190709-082606901", "type": "article", "title": "Plasma environment effects on K lines of astrophysical interest. II. Ionization potentials, K thresholds, radiative rates, and Auger widths in Ne- through He-like iron ions (Fe\u202fXVII \u2013 Fe\u202fXXV)", "author": [ { "family_name": "Deprince", "given_name": "J.", "orcid": "0000-0002-3409-8232", "clpid": "Deprince-J\u00e9r\u00f4me" }, { "family_name": "Bautista", "given_name": "M. A.", "clpid": "Bautista-M-A" }, { "family_name": "Fritzsche", "given_name": "S.", "clpid": "Fritzsche-Stephan" }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Kallman", "given_name": "T.", "orcid": "0000-0002-5779-6906", "clpid": "Kallman-Timothy-R" }, { "family_name": "Mendoza", "given_name": "C.", "clpid": "Mendoza-C" }, { "family_name": "Palmeri", "given_name": "P.", "clpid": "Palmeri-P" }, { "family_name": "Quinet", "given_name": "P.", "clpid": "Quinet-P" } ], "abstract": "Aims. In the context of accretion disks around black holes, we estimate plasma-environment effects on the atomic parameters associated with the decay of K-vacancy states in highly charged iron ions, namely Fe\u202fXVII \u2013 Fe\u202fXXV. \n\nMethods. Within the relativistic multiconfiguration Dirac\u2013Fock (MCDF) framework, the electron\u2013nucleus and electron\u2013electron plasma screenings were approximated with a time-averaged Debye\u2013H\u00fcckel potential. \n\nResults. Modified ionization potentials, K thresholds, wavelengths, radiative emission rates, and Auger widths are reported for astrophysical plasmas characterized by electron temperatures and densities in the ranges 10^5 \u2212 10^7 K and 10^(18) \u2212 10^(22) cm^(\u22123), respectively. \n\nConclusions. We conclude that the high-resolution microcalorimeters on board future X-ray missions such as XRISM and ATHENA are expected to be sensitive to the lowering of the iron K edge due to the extreme plasma conditions occurring in accretion disks around compact objects.", "doi": "10.1051/0004-6361/201935444", "issn": "0004-6361", "publisher": "EDP Sciences", "publication": "Astronomy and Astrophysics", "publication_date": "2019-06", "volume": "626", "pages": "Art. No. A83" }, { "id": "authors:ph73s-rya83", "collection": "authors", "collection_id": "ph73s-rya83", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190418-092902776", "type": "article", "title": "About the Kerr Nature of the Stellar-mass Black Hole in GRS 1915+105", "author": [ { "family_name": "Zhang", "given_name": "Yuexin", "clpid": "Zhang-Yuexin" }, { "family_name": "Abdikamalov", "given_name": "Askar B.", "clpid": "Abdikamalov-A-B" }, { "family_name": "Ayzenberg", "given_name": "Dimitry", "clpid": "Ayzenberg-D" }, { "family_name": "Bambi", "given_name": "Cosimo", "orcid": "0000-0002-3180-9502", "clpid": "Bambi-C" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-T" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Nampalliwar", "given_name": "Sourabh", "clpid": "Nampalliwar-S" } ], "abstract": "We employ the accretion disk reflection model RELXILL_NK to test the spacetime geometry around the stellar-mass black hole in GRS 1915+105. We adopt the Johannsen metric with the deformation parameters \u03b1_(13) and \u03b1_(22), for which the Kerr solution is recovered when \u03b1_(13) = \u03b1_(22) = 0. We analyze a NuSTAR observation of 2012, obtaining vanishing and non-vanishing values of the deformation parameters depending on the astrophysical model adopted. Similar difficulties were not found in our previous tests with other sources. The results of this work can shed light on the choice of sources suitable for testing the Kerr metric using X-ray reflection spectroscopy and on the parts of our reflection models that more urgently require improvement.", "doi": "10.3847/1538-4357/ab0e79", "issn": "1538-4357", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2019-04-10", "series_number": "1", "volume": "875", "issue": "1", "pages": "Art. No. 41" }, { "id": "authors:gre4w-qpc11", "collection": "authors", "collection_id": "gre4w-qpc11", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190417-154831558", "type": "article", "title": "Toward Precision Tests of General Relativity with Black Hole X-Ray Reflection Spectroscopy", "author": [ { "family_name": "Tripathi", "given_name": "Ashutosh", "orcid": "0000-0002-3960-5870", "clpid": "Tripathi-A" }, { "family_name": "Nampalliwar", "given_name": "Sourabh", "clpid": "Nampalliwar-S" }, { "family_name": "Abdikamalov", "given_name": "Askar B.", "clpid": "Abdikamalov-A-B" }, { "family_name": "Ayzenberg", "given_name": "Dimitry", "clpid": "Ayzenberg-D" }, { "family_name": "Bambi", "given_name": "Cosimo", "orcid": "0000-0002-3180-9502", "clpid": "Bambi-C" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-T" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Marinucci", "given_name": "Andrea", "clpid": "Marinucci-A" } ], "abstract": "Astrophysical black hole systems are the ideal laboratories for testing Einstein's theory of gravity in the strong field regime. We have recently developed a framework that uses the reflection spectrum of black hole systems to perform precision tests of general relativity by testing the Kerr black hole hypothesis. In this paper, we analyze XMM-Newton and NuSTAR observations of the supermassive black hole in the Seyfert 1 galaxy MCG\u201306\u201330\u201315 with our disk reflection model. We consider the Johannsen metric with the deformation parameters \u03b1_(13) and \u03b1_(22), which quantify deviations from the Kerr metric. For \u03b1_(22) = 0, we obtain the black hole spin 0.928 < a* < 0.983 and -0.44 < \u03b1_(13) < 0.15. For \u03b1_(13) = 0, we obtain 0.885 < a* < 0.987 and -0.12 < \u03b1_(22) < 1.05 . The Kerr solution is recovered for \u03b1_(13) = \u03b1_(22) = 0. Thus, our results include the Kerr solution within statistical uncertainties. Systematic uncertainties are difficult to account for, and we discuss some issues in this regard.", "doi": "10.3847/1538-4357/ab0e7e", "issn": "1538-4357", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2019-04-10", "series_number": "1", "volume": "875", "issue": "1", "pages": "Art. No. 56" }, { "id": "authors:ad9jg-fmw54", "collection": "authors", "collection_id": "ad9jg-fmw54", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190222-073613522", "type": "article", "title": "A low-flux state in IRAS\u200900521\u22127054 seen with NuSTAR and XMM\u2013Newton: relativistic reflection and an ultrafast outflow", "author": [ { "family_name": "Walton", "given_name": "D. J.", "orcid": "0000-0001-5819-3552", "clpid": "Walton-D-J" }, { "family_name": "Nardini", "given_name": "E.", "orcid": "0000-0001-9226-8992", "clpid": "Nardini-E" }, { "family_name": "Gallo", "given_name": "L. C.", "clpid": "Gallo-L-C" }, { "family_name": "Reynolds", "given_name": "M. T.", "clpid": "Reynolds-M-T" }, { "family_name": "Ricci", "given_name": "C.", "orcid": "0000-0001-5231-2645", "clpid": "Ricci-C" }, { "family_name": "Dauser", "given_name": "T.", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-T" }, { "family_name": "Fabian", "given_name": "A. C.", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-A-C" }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Harrison", "given_name": "F. A.", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" }, { "family_name": "Risaliti", "given_name": "G.", "clpid": "Risaliti-G" }, { "family_name": "Stern", "given_name": "D.", "orcid": "0000-0003-2686-9241", "clpid": "Stern-D" } ], "abstract": "We present results from a deep, coordinated XMM\u2013Newton + NuSTARobservation of the Seyfert 2 galaxy IRAS\u200900521\u22127054. The NuSTAR data provide the first detection of this source in high-energy X-rays (E > 10\u2009keV), and the broad-band data show this to be a highly complex source which exhibits relativistic reflection from the inner accretion disc, further reprocessing by more distant material, neutral absorption, and evidence for ionized absorption in an extreme, ultrafast outflow (\u2060v_(out) \u223c 0.4c). Based on lamppost disc reflection models, we find evidence that the central supermassive black hole is rapidly rotating (a > 0.77), consistent with previous estimates from the profile of the relativistic iron line, and that the accretion disc is viewed at a fairly high inclination (i \u223c 59\u00b0). Based on extensive simulations, we find the ultrafast outflow is detected at \u223c4\u03c3 significance (or greater). We also estimate that the extreme outflow should be sufficient to power galaxy-scale feedback, and may even dominate the energetics of the total output from the system.", "doi": "10.1093/mnras/stz115", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2019-04-01", "series_number": "2", "volume": "484", "issue": "2", "pages": "2544-2555" }, { "id": "authors:3mmw8-84f32", "collection": "authors", "collection_id": "3mmw8-84f32", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190401-084307071", "type": "article", "title": "Constraints on the Spacetime Metric around Seven \"Bare\" AGNs Using X-Ray Reflection Spectroscopy", "author": [ { "family_name": "Tripathi", "given_name": "Ashutosh", "orcid": "0000-0002-3960-5870", "clpid": "Tripathi-A" }, { "family_name": "Yan", "given_name": "Jinli", "clpid": "Yan-Jinli" }, { "family_name": "Yang", "given_name": "Yuchan", "clpid": "Yang-Yuchan" }, { "family_name": "Yan", "given_name": "Yunfeng", "clpid": "Yan-Yunfeng" }, { "family_name": "Garnham", "given_name": "Marcus", "clpid": "Garnham-M" }, { "family_name": "Yao", "given_name": "Yu", "clpid": "Yao-Yu" }, { "family_name": "Li", "given_name": "Songcheng", "clpid": "Li-Songcheng" }, { "family_name": "Ding", "given_name": "Ziyu", "clpid": "Ding-Ziyu" }, { "family_name": "Abdikamalov", "given_name": "Askar B.", "clpid": "Abdikamalov-A-B" }, { "family_name": "Ayzenberg", "given_name": "Dimitry", "clpid": "Ayzenberg-D" }, { "family_name": "Bambi", "given_name": "Cosimo", "orcid": "0000-0002-3180-9502", "clpid": "Bambi-C" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-T" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Jiang", "given_name": "Jiachen", "orcid": "0000-0002-9639-4352", "clpid": "Jiang-Jiachen" }, { "family_name": "Nampalliwar", "given_name": "Sourabh", "clpid": "Nampalliwar-S" } ], "abstract": "We present the study of a sample of seven \"bare\" active galactic nuclei observed with Suzaku. We interpret the spectrum of these sources with a relativistic reflection component and we employ our model relxill_nk to test the Kerr nature of their supermassive black holes. We constrain the Johannsen deformation parameters \u03b1_(13) and \u03b1_(22), in which the Kerr metric is recovered when \u03b1_(13) = \u03b1_(22) = 0. All our measurements are consistent with the hypothesis that the spacetime geometry around these supermassive objects is described by the Kerr solution. For some sources, we obtain quite strong constraints on \u03b1_(13) and \u03b1_(22) when compared to those found in our previous studies. We discuss the systematic uncertainties in our tests and the implications of our results.", "doi": "10.3847/1538-4357/ab0a00", "issn": "1538-4357", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2019-04-01", "series_number": "2", "volume": "874", "issue": "2", "pages": "Art. No. 135" }, { "id": "authors:3xwe9-g3r14", "collection": "authors", "collection_id": "3xwe9-g3r14", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190416-083122873", "type": "article", "title": "High-density reflection spectroscopy: I. A case study of GX\u00a0339-4", "author": [ { "family_name": "Jiang", "given_name": "Jiachen", "orcid": "0000-0002-9639-4352", "clpid": "Jiang-Jiachen" }, { "family_name": "Fabian", "given_name": "Andrew C.", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-A-C" }, { "family_name": "Wang", "given_name": "Jingyi", "orcid": "0000-0002-1742-2125", "clpid": "Wang-Jingyi" }, { "family_name": "Walton", "given_name": "Dominic J.", "orcid": "0000-0001-5819-3552", "clpid": "Walton-D-J" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Parker", "given_name": "Michael L.", "orcid": "0000-0002-8466-7317", "clpid": "Parker-M-L" }, { "family_name": "Steiner", "given_name": "James F.", "orcid": "0000-0002-5872-6061", "clpid": "Steiner-J-F" }, { "family_name": "Tomsick", "given_name": "John A.", "orcid": "0000-0001-5506-9855", "clpid": "Tomsick-J-A" } ], "abstract": "We present a broad-band spectral analysis of the black hole binary GX 339-4 with NuSTAR and Swift using high-density reflection model. The observations were taken when the source was in low-flux (LF) hard states during the outbursts in 2013 and 2015, and in a very high-flux (HF) soft state in 2015. The high-density reflection model can explain its LF spectra with no requirement for an additional low temperature thermal component. This model enables us to constrain the density in the disc surface of GX 339-4 in different flux states. The disc density in the LF state is log\u2009(ne/\u2009cm^(\u22123)) \u2248 21, 100 times higher than the density in the HF state (log\u2009(n_e/\u2009cm^(\u22123)) = 18.93^(+0.12)_(\u22120.16). A close-to-solar iron abundance is obtained by modelling the LF and HF broad-band spectra with variable density reflection model (\u2060Z_(Fe) = 1.50^(+0.12)_(\u22120.04)Z\u2299 and Z_(Fe) = 1.05^(+0.17)_(\u22120.15)Z\u2299, respectively).", "doi": "10.1093/mnras/stz095", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2019-04", "series_number": "2", "volume": "484", "issue": "2", "pages": "1972-1982" }, { "id": "authors:v3b9d-6m540", "collection": "authors", "collection_id": "v3b9d-6m540", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190416-091633773", "type": "article", "title": "Nuclear spallation in active galaxies", "author": [ { "family_name": "Gallo", "given_name": "L. C.", "clpid": "Gallo-L-C" }, { "family_name": "Randhawa", "given_name": "J. S.", "clpid": "Randhawa-J-S" }, { "family_name": "Waddell", "given_name": "S. G. H.", "clpid": "Waddell-S-G-H" }, { "family_name": "Hani", "given_name": "M. H.", "orcid": "0000-0002-5351-2291", "clpid": "Hani-M-H" }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Reynolds", "given_name": "C. S.", "clpid": "Reynolds-C-S" } ], "abstract": "A number of works point to the presence of narrow emission features at unusual energies in the X-ray spectra of active galactic nuclei or to potentially low iron abundances as possible evidence for the spallation of iron. With the imminence of high-resolution calorimeter spectroscopy, the potential to test spallation models in astrophysical sources will soon be possible. Previously determined nuclear spallation reactions of Fe are recalculated making use of improved total inelastic and partial reaction cross-sections that result in different absolute and relative abundances of the main spallation elements Mn, Cr, V, and Ti. The effects of ionization and dynamics near the black hole are examined in simulated spectra with CCD and calorimeter (i.e. Hitomi) resolution. With high resolution, differences in relative abundances and ionization should be detectable if spallation is originating at large distances from the black hole (e.g. torus or disc wind), where blurring is not significant. If spallation were occurring in the inner accretion disc, it would likely be undetected as blurring effects would cause significant blending of spectral features.", "doi": "10.1093/mnras/stz260", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2019-04", "series_number": "3", "volume": "484", "issue": "3", "pages": "3036-3041" }, { "id": "authors:hgjc7-c8319", "collection": "authors", "collection_id": "hgjc7-c8319", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190425-153726886", "type": "article", "title": "Plasma environment effects on K lines of astrophysical interest. I. Atomic structure, radiative rates, and Auger widths of oxygen ions", "author": [ { "family_name": "Deprince", "given_name": "J.", "orcid": "0000-0002-3409-8232", "clpid": "Deprince-J\u00e9r\u00f4me" }, { "family_name": "Bautista", "given_name": "M. A.", "clpid": "Bautista-M-A" }, { "family_name": "Fritzsche", "given_name": "S.", "clpid": "Fritzsche-Stephan" }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Kallman", "given_name": "T. R.", "orcid": "0000-0002-5779-6906", "clpid": "Kallman-Timothy-R" }, { "family_name": "Mendoza", "given_name": "C.", "clpid": "Mendoza-C" }, { "family_name": "Palmeri", "given_name": "P.", "clpid": "Palmeri-P" }, { "family_name": "Quinet", "given_name": "P.", "clpid": "Quinet-P" } ], "abstract": "Aims. In the context of black-hole accretion disks, the main goal of the present study is to estimate the plasma environment effects on the atomic structure and radiative parameters associated with the K-vacancy states in ions of the oxygen isonuclear sequence. \n\nMethods. We used a time-averaged Debye\u2013H\u00fcckel potential for both the electron\u2013nucleus and the electron\u2013electron interactions implemented in the fully relativistic multiconfiguration Dirac\u2013Fock (MCDF) method. \n\nResults. Modified ionization potentials, K thresholds, Auger widths, and radiative transition wavelengths and rates are reported for O\u202fI\u2013O\u202fVII in plasma environments with electron temperature and density ranges 10^5\u221210^7 K and 10^(18)\u221210^(22) cm^(\u22123).", "doi": "10.1051/0004-6361/201935075", "issn": "0004-6361", "publisher": "EDP Sciences", "publication": "Astronomy and Astrophysics", "publication_date": "2019-04", "volume": "624", "pages": "Art. No. A74" }, { "id": "authors:byx2b-pjy19", "collection": "authors", "collection_id": "byx2b-pjy19", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190619-103025261", "type": "publication_whitepaper", "title": "Probing the Black Hole Engine with Measurements of the Relativistic X-ray Reflection Component", "author": [ { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Bachetti", "given_name": "Matteo", "orcid": "0000-0002-4576-9337", "clpid": "Bachetti-M" }, { "family_name": "Ballantyne", "given_name": "David R.", "orcid": "0000-0001-8128-6976", "clpid": "Ballantyne-D-R" }, { "family_name": "Brenneman", "given_name": "Laura", "clpid": "Brenneman-L-W" }, { "family_name": "Brightman", "given_name": "Murray", "orcid": "0000-0002-8147-2602", "clpid": "Brightman-M" }, { "family_name": "Connors", "given_name": "Riley M.", "orcid": "0000-0002-8908-759X", "clpid": "Connors-R-M-T" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-T" }, { "family_name": "Fabian", "given_name": "Andrew", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-A-C" }, { "family_name": "Fuerst", "given_name": "Felix", "orcid": "0000-0003-0388-0560", "clpid": "F\u00fcrst-F" }, { "family_name": "Gandhi", "given_name": "Poshak", "orcid": "0000-0003-3105-2615", "clpid": "Gandhi-Poshak" }, { "family_name": "Kamraj", "given_name": "Nikita", "orcid": "0000-0002-3233-2451", "clpid": "Kamraj-N" }, { "family_name": "Kara", "given_name": "Erin", "orcid": "0000-0003-0172-0854", "clpid": "Kara-E" }, { "family_name": "Madsen", "given_name": "Kristin", "orcid": "0000-0003-1252-4891", "clpid": "Madsen-K-K" }, { "family_name": "Miller", "given_name": "Jon M.", "clpid": "Miller-J-M" }, { "family_name": "Nowak", "given_name": "Michael", "orcid": "0000-0001-6923-1315", "clpid": "Nowak-M-A" }, { "family_name": "Parker", "given_name": "Michael L.", "orcid": "0000-0002-8466-7317", "clpid": "Parker-M-L" }, { "family_name": "Reynolds", "given_name": "Christopher", "clpid": "Reynolds-C-S" }, { "family_name": "Steiner", "given_name": "James", "orcid": "0000-0002-5872-6061", "clpid": "Steiner-J-F" }, { "family_name": "Stern", "given_name": "Daniel", "orcid": "0000-0003-2686-9241", "clpid": "Stern-D" }, { "family_name": "Taylor", "given_name": "Corbin", "clpid": "Taylor-C" }, { "family_name": "Tomsick", "given_name": "John", "orcid": "0000-0001-5506-9855", "clpid": "Tomsick-J-A" }, { "family_name": "Walton", "given_name": "Dominic", "orcid": "0000-0001-5819-3552", "clpid": "Walton-D-J" }, { "family_name": "Wilms", "given_name": "J\u00f6rn", "orcid": "0000-0003-2065-5410", "clpid": "Wilms-J" }, { "family_name": "Zoghbi", "given_name": "Abderahmen", "orcid": "0000-0002-0572-9613", "clpid": "Zoghbi-A" } ], "abstract": "Over the last decades X-ray spectroscopy has proven to be a powerful tool for the estimation of black hole spin and several other key parameters in dozens of AGN and black hole X-ray binaries. In this White Paper, we discuss the observational and theoretical challenges expected in the exploration, discovery, and study of astrophysical black holes in the next decade. We focus on the case of accreting black holes and their electromagnetic signatures, with particular emphasis on the measurement of the relativistic reflection component in their X-ray spectra.", "doi": "10.48550/arXiv.1903.07130", "publisher": "arXiv", "publication_date": "2019-03-17" }, { "id": "authors:xmn7m-rrr02", "collection": "authors", "collection_id": "xmn7m-rrr02", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190617-141021193", "type": "publication_whitepaper", "title": "Breaking the limit: Super-Eddington accretion onto black holes and neutron stars", "author": [ { "family_name": "Brightman", "given_name": "M.", "orcid": "0000-0002-8147-2602", "clpid": "Brightman-Murray" }, { "family_name": "Bachetti", "given_name": "M.", "orcid": "0000-0002-4576-9337", "clpid": "Bachetti-Matteo" }, { "family_name": "Earnshaw", "given_name": "H. P.", "orcid": "0000-0001-5857-5622", "clpid": "Earnshaw-Hannah-P" }, { "family_name": "F\u00fcrst", "given_name": "F.", "orcid": "0000-0003-0388-0560", "clpid": "F\u00fcrst-Felix" }, { "family_name": "Garc\u00eda", "given_name": "J.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Grefenstette", "given_name": "B.", "orcid": "0000-0002-1984-2932", "clpid": "Grefenstette-Brian-W" }, { "family_name": "Heida", "given_name": "M.", "orcid": "0000-0002-1082-7496", "clpid": "Heida-Marianne" }, { "family_name": "Kara", "given_name": "E.", "orcid": "0000-0003-0172-0854", "clpid": "Kara-Erin" }, { "family_name": "Madsen", "given_name": "K. K.", "orcid": "0000-0003-1252-4891", "clpid": "Madsen-Kristin-K" }, { "family_name": "Middleton", "given_name": "M. J.", "orcid": "0000-0002-8183-2970", "clpid": "Middleton-Matthew-J" }, { "family_name": "Stern", "given_name": "D.", "orcid": "0000-0003-2686-9241", "clpid": "Stern-Daniel" }, { "family_name": "Tombesi", "given_name": "F.", "orcid": "0000-0002-6562-8654", "clpid": "Tombesi-Francesco" }, { "family_name": "Walton", "given_name": "D. J.", "orcid": "0000-0001-5819-3552", "clpid": "Walton-Dominic-J" } ], "abstract": "With the recent discoveries of massive and highly luminous quasars at high redshifts (z\u223c7; e.g. Mortlock et al. 2011), the question of how black holes (BHs) grow in the early Universe has been cast in a new light. In order to grow BHs with M_(BH) > 10^9 M\u2299 by less than a billion years after the Big Bang, mass accretion onto the low-mass seed BHs needs to have been very rapid (Volonteri & Rees, 2005). Indeed, for any stellar remnant seed, the rate required would need to exceed the Eddington limit. This is the point at which the outward force produced by radiation pressure is equal to the gravitational attraction experienced by the in-falling matter. In principle, this implies that there is a maximum luminosity an object of mass M can emit; assuming spherical accretion and that the opacity is dominated by Thompson scattering, this Eddington luminosity is L_E = 1.38\u00d710^(38)(M/M\u2299) erg s^(\u22121). In reality, it is known that this limit can be violated, due to non-spherical geometry or various kinds of instabilities. Nevertheless, the Eddington limit remains an important reference point, and many of the details of how accretion proceeds above this limit remain unclear. Understanding how this so-called super-Eddington accretion occurs is of clear cosmological importance, since it potentially governs the growth of the first supermassive black holes (SMBHs) and the impact this growth would have had on their host galaxies ('feedback') and the epoch of reionization, as well as improving our understanding of accretion physics more generally.", "doi": "10.48550/arXiv.1903.06844", "publisher": "arXiv", "publication_date": "2019-03-15" }, { "id": "authors:xm1rg-xjj17", "collection": "authors", "collection_id": "xm1rg-xjj17", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190225-075539902", "type": "article", "title": "NuSTAR Observations of the Accreting Atolls GX 3+1, 4U 1702-429, 4U 0614+091, and 4U 1746-371", "author": [ { "family_name": "Ludlam", "given_name": "R. M.", "orcid": "0000-0002-8961-939X", "clpid": "Ludlam-R-M" }, { "family_name": "Miller", "given_name": "J. M.", "clpid": "Miller-J-M" }, { "family_name": "Barret", "given_name": "D.", "orcid": "0000-0002-0393-9190", "clpid": "Barret-D" }, { "family_name": "Cackett", "given_name": "E. M.", "orcid": "0000-0002-8294-9281", "clpid": "Cackett-E-M" }, { "family_name": "Coughenour", "given_name": "B. M.", "clpid": "Coughenour-B-M" }, { "family_name": "Dauser", "given_name": "T.", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-T" }, { "family_name": "Degenaar", "given_name": "N.", "clpid": "Degenaar-N" }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Harrison", "given_name": "F. A.", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" }, { "family_name": "Paerels", "given_name": "F.", "clpid": "Paerels-F" } ], "abstract": "Atoll sources are accreting neutron star (NS) low-mass X-ray binaries. We present a spectral analysis of four persistent atoll sources (GX 3+1, 4U 1702\u2212429, 4U 0614+091, and 4U 1746\u2212371) observed for ~20 ks each with NuSTAR to determine the extent of the inner accretion disk. These sources range from an apparent luminosity of 0.006\u20130.11 of the Eddington limit (assuming the empirical limit of 3.8 \u00d7 10^(38) erg s^(\u22121)). Broad Fe emission features shaped by Doppler and relativistic effects close to the NS were firmly detected in three of these sources. The position of the disk appears to be close to the innermost stable circular orbit (ISCO) in each case. For GX 3+1, we determine R_(in) = 1.8^(+0.2)_(\u22120.6) R_(ISCO) (90% confidence level) and an inclination of 27\u00b0\u201331\u00b0. For 4U 1702\u2212429, we find a R_(in) = 1.5^(+1.6)_(\u22120.4) R_(ISCO) and inclination of 53\u00b0\u201364\u00b0. For 4U 0614+091, the disk has a position of R_(in) = 1.3^(+5.4)_(\u22120.2) R_(ISCO) and inclination of 50\u00b0\u201362\u00b0. If the disk does not extend to the innermost stable circular orbit, we can place conservative limits on the magnetic field strength in these systems in the event that the disk is truncated at the Alfv\u00e9n radius. This provides the limit at the poles of B \u2264 6.7 \u00d7 10^8 G, 3.3 \u00d7 10^8 G, and 14.5 \u00d7 10^8 G for GX 3+1, 4U 1702\u2212429, and 4U 0614+091, respectively. For 4U 1746\u2212371, we argue that the most plausible explanation for the lack of reflection features is a combination of source geometry and strong Comptonization. We place these sources among the larger sample of NSs that have been observed with NuSTAR.", "doi": "10.3847/1538-4357/ab0414", "issn": "1538-4357", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2019-03-01", "series_number": "1", "volume": "873", "issue": "1", "pages": "Art. No. 99" }, { "id": "authors:dgb5m-8gg29", "collection": "authors", "collection_id": "dgb5m-8gg29", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190905-124135494", "type": "article", "title": "On the discrepancy between the X-ray and UV absorption measurements of O\u00a0VI in the local ISM", "author": [ { "family_name": "Gatuzz", "given_name": "Efra\u00edn", "orcid": "0000-0002-3252-9633", "clpid": "Gatuzz-E" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Kallman", "given_name": "Timothy R.", "orcid": "0000-0002-5779-6906", "clpid": "Kallman-Timothy-R" } ], "abstract": "The total amount of O\u2009VI present in the interstellar medium (ISM) obtained via absorption measurements in UV and X-ray spectra is currently in disagreement, with the latter being significantly larger (by a factor of 10 or more) than the former. Previous works have proposed that the blend of the O\u2009VIK\u03b1 line (22.032 \u00c5) with the O\u2009II K\u03b2-L12 line (22.04 \u00c5) could account for the stronger absorption observed in the X-ray spectra. Here, we present a detailed study of the oxygen absorption in the local ISM, implementing our new model IGMabs which includes photoabsorption cross-sections of highly ionized species of abundant elements as well as turbulence broadening. By analysing high-resolution Chandra spectra of 13 low-mass X-ray binaries (LMXBs) and 29 extragalactic sources, we have estimated the column densities of O\u2009I \u2013 O\u2009III and from O\u2009VI \u2013 O\u2009VIII along multiple line-of-sights. We find that in most cases the O\u2009II K\u03b2-L12 line accounts for <30 per cent of the total O\u2009VI K \u03b1 + O\u2009II K \u03b2. We conclude that the amount of O\u2009II predicted by our model is still insufficient to explain the discrepancy between X-ray and UV measurements of O\u2009VI column densities.", "doi": "10.1093/mnrasl/sly223", "issn": "1745-3925", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society: Letters", "publication_date": "2019-02", "series_number": "1", "volume": "483", "issue": "1", "pages": "L75-L79" }, { "id": "authors:m8vy1-48w82", "collection": "authors", "collection_id": "m8vy1-48w82", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190124-112047031", "type": "article", "title": "Implications of the Warm Corona and Relativistic Reflection Models for the Soft Excess in Mrk 509", "author": [ { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Kara", "given_name": "Erin", "orcid": "0000-0003-0172-0854", "clpid": "Kara-E" }, { "family_name": "Walton", "given_name": "Dominic", "orcid": "0000-0001-5819-3552", "clpid": "Walton-D-J" }, { "family_name": "Beuchert", "given_name": "Tobias", "clpid": "Beuchert-T" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-T" }, { "family_name": "Gatuzz", "given_name": "Efrain", "orcid": "0000-0002-3252-9633", "clpid": "Gatuzz-E" }, { "family_name": "Balokovi\u0107", "given_name": "Mislav", "orcid": "0000-0003-0476-6647", "clpid": "Balokovi\u0107-M" }, { "family_name": "Steiner", "given_name": "James F.", "orcid": "0000-0002-5872-6061", "clpid": "Steiner-J-F" }, { "family_name": "Tombesi", "given_name": "Francesco", "orcid": "0000-0002-6562-8654", "clpid": "Tombesi-F" }, { "family_name": "Connors", "given_name": "Riley M. T.", "orcid": "0000-0002-8908-759X", "clpid": "Connors-R-M-T" }, { "family_name": "Kallman", "given_name": "Timothy R.", "orcid": "0000-0002-5779-6906", "clpid": "Kallman-Timothy-R" }, { "family_name": "Harrison", "given_name": "Fiona A.", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" }, { "family_name": "Fabian", "given_name": "Andrew", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-A-C" }, { "family_name": "Wilms", "given_name": "J\u00f6rn", "orcid": "0000-0003-2065-5410", "clpid": "Wilms-J" }, { "family_name": "Stern", "given_name": "Daniel", "orcid": "0000-0003-2686-9241", "clpid": "Stern-D" }, { "family_name": "Lanz", "given_name": "Lauranne", "orcid": "0000-0002-3249-8224", "clpid": "Lanz-L" }, { "family_name": "Ricci", "given_name": "Claudio", "orcid": "0000-0001-5231-2645", "clpid": "Ricci-C" }, { "family_name": "Ballantyne", "given_name": "David R.", "orcid": "0000-0001-8128-6976", "clpid": "Ballantyne-D-R" } ], "abstract": "We present the analysis of the first Nuclear Spectroscopic Telescope Array observations (~220 ks), simultaneous with the last Suzaku observations (~50 ks), of the active galactic nucleus of the bright Seyfert 1 galaxy Mrk 509. The time-averaged spectrum in the 1\u201379 keV X-ray band is dominated by a power-law continuum (\u0393 ~ 1.8\u20131.9), a strong soft excess around 1 keV, and signatures of X-ray reflection in the form of Fe K emission (~6.4 keV), an Fe K absorption edge (~7.1 keV), and a Compton hump due to electron scattering (~20\u201330 keV). We show that these data can be described by two very different prescriptions for the soft excess: a warm (kT ~ 0.5\u20131 keV) and optically thick (\u03c4 ~ 10\u201320) Comptonizing corona or a relativistically blurred ionized reflection spectrum from the inner regions of the accretion disk. While these two scenarios cannot be distinguished based on their fit statistics, we argue that the parameters required by the warm corona model are physically incompatible with the conditions of standard coronae. Detailed photoionization calculations show that even in the most favorable conditions, the warm corona should produce strong absorption in the observed spectrum. On the other hand, while the relativistic reflection model provides a satisfactory description of the data, it also requires extreme parameters, such as maximum black hole spin, a very low and compact hot corona, and a very high density for the inner accretion disk. Deeper observations of this source are thus necessary to confirm the presence of relativistic reflection and further understand the nature of its soft excess.", "doi": "10.3847/1538-4357/aaf739", "issn": "1538-4357", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2019-01-20", "series_number": "1", "volume": "871", "issue": "1", "pages": "Art. No. 88" }, { "id": "authors:g4bc7-dqp55", "collection": "authors", "collection_id": "g4bc7-dqp55", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20181001-131357805", "type": "article", "title": "A Study of the Strong Gravity Region of the Black Hole in GS 1354\u2013645", "author": [ { "family_name": "Xu", "given_name": "Yerong", "clpid": "Xu-Yerong" }, { "family_name": "Nampalliwar", "given_name": "Sourabh", "clpid": "Nampalliwar-S" }, { "family_name": "Abdikamalov", "given_name": "Askar B.", "clpid": "Abdikamalov-A-B" }, { "family_name": "Ayzenberg", "given_name": "Dimitry", "clpid": "Ayzenberg-D" }, { "family_name": "Bambi", "given_name": "Cosimo", "orcid": "0000-0002-3180-9502", "clpid": "Bambi-C" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-T" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Jiang", "given_name": "Jiachen", "orcid": "0000-0002-9639-4352", "clpid": "Jiang-Jiachen" } ], "abstract": "It is thought that the spacetime metric around astrophysical black holes is well described by the Kerr solution of Einstein's gravity. However, robust observational evidence of the Kerr nature of these objects is still lacking. Here we fit the X-ray spectrum of the stellar-mass black hole in GS 1354\u2013645 with a disk reflection model beyond Einstein's gravity in order test the Kerr black hole hypothesis. We consider the Johannsen metric with the deformation parameters \u03b1_(13) and \u03b1_(22). The Kerr metric is recovered for \u03b1_(13) = \u03b1_(22) = 0. For \u03b1_(22) = 0, our measurements of the black hole spin and of the deformation parameter \u03b1 13 are a_* > 0.975 and \u22120.34 < \u03b1_(13) < 0.16, respectively. For \u03b1 13 = 0, we find a_* > 0.975 and \u22120.09 < \u03b1_(22) < 0.42. All the reported uncertainties are at 99% of confidence level for two relevant parameters.", "doi": "10.3847/1538-4357/aadb9d", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2018-10-01", "series_number": "2", "volume": "865", "issue": "2", "pages": "Art. No. 134" }, { "id": "authors:7smm9-mbz16", "collection": "authors", "collection_id": "7smm9-mbz16", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180906-135359593", "type": "article", "title": "3D mapping of the neutral X-ray absorption in the local interstellar medium: the Gaia and XMM-Newton synergy", "author": [ { "family_name": "Gatuzz", "given_name": "Efra\u00edn", "orcid": "0000-0002-3252-9633", "clpid": "Gatuzz-E" }, { "family_name": "Rezaei Kh.", "given_name": "S.", "clpid": "Rezaei-Kh-S" }, { "family_name": "Kallman", "given_name": "Timothy R.", "orcid": "0000-0002-5779-6906", "clpid": "Kallman-Timothy-R" }, { "family_name": "Kreikenbohm", "given_name": "Annika", "clpid": "Kreikenbohm-A" }, { "family_name": "Oertel", "given_name": "Mirjam", "clpid": "Oertel-M" }, { "family_name": "Wilms", "given_name": "J.", "orcid": "0000-0003-2065-5410", "clpid": "Wilms-J" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" } ], "abstract": "We present a three-dimensional map of the hydrogen density distribution in the Galactic interstellar medium. The hydrogen-equivalent column densities were obtained from the Exploring the X-ray Transient and variable Sky project (EXTRAS) which provides equivalent N_H values from X-ray spectral fits of observations within the XMM-Newton Data Release. EXTRAS include multiple fits for each source, allowing an accurate determination of the equivalent column densities, which depends on the continuum modelling of the spectra. A cross-correlation between the EXTRAS catalogue and the first Gaia Data Release was performed in order to obtain accurate parallax and distance measurements. We use a Bayesian method explained in Rezaei Kh. et al. (2017) in order to predict the most probable distribution of the density at any arbitrary point, even for lines of sight along which there are no initial observation. The resulting map shows small-scale density structures which could not have been modelled by using analytic density profiles. In this paper, we present a proof of concept of the kind of science possible with the synergy of these catalogues. However, given the systematic uncertainties connected to the source identification and to the dependence of N_H on the spectral model, the present maps should be considered qualitatively at this point.", "doi": "10.1093/mnras/sty1738", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2018-09-21", "series_number": "3", "volume": "479", "issue": "3", "pages": "3715-3725" }, { "id": "authors:r9vxs-49d20", "collection": "authors", "collection_id": "r9vxs-49d20", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180918-091012752", "type": "article", "title": "The Hard State of the Highly Absorbed High Inclination Black Hole Binary Candidate Swift J1658.2\u20134242 Observed by NuSTAR and Swift", "author": [ { "family_name": "Xu", "given_name": "Yanjun", "orcid": "0000-0003-2443-3698", "clpid": "Xu-Yanjun" }, { "family_name": "Harrison", "given_name": "Fiona A.", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" }, { "family_name": "Kennea", "given_name": "Jamie A.", "orcid": "0000-0002-6745-4790", "clpid": "Kennea-J-A" }, { "family_name": "Walton", "given_name": "Dominic J.", "orcid": "0000-0001-5819-3552", "clpid": "Walton-D-J" }, { "family_name": "Tomsick", "given_name": "John A.", "orcid": "0000-0001-5506-9855", "clpid": "Tomsick-J-A" }, { "family_name": "Miller", "given_name": "Jon M.", "clpid": "Miller-J-M" }, { "family_name": "Barret", "given_name": "Didier", "orcid": "0000-0002-0393-9190", "clpid": "Barret-D" }, { "family_name": "Fabian", "given_name": "Andrew C.", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-A-C" }, { "family_name": "Forster", "given_name": "Karl", "orcid": "0000-0001-5800-5531", "clpid": "Forster-K" }, { "family_name": "F\u00fcrst", "given_name": "Felix", "orcid": "0000-0003-0388-0560", "clpid": "F\u00fcrst-F" }, { "family_name": "Gandhi", "given_name": "Poshak", "orcid": "0000-0003-3105-2615", "clpid": "Gandhi-Poshak" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" } ], "abstract": "We present a spectral and timing analysis of the newly reported Galactic X-ray transient Swift J1658.2\u20134242 observed by Nuclear Spectroscopic Telescope Array (NuSTAR) and Swift. The broadband X-ray continuum is typical of a black hole binary in the bright hard state, with a photon index of \u0393 = 1.63 \u00b1 0.02 and a low coronal temperature of kT_e = 22 \u00b1 1 keV, corresponding to a low spectral cutoff well constrained by NuSTAR. Spectral modeling of the relativistic disk reflection features, consisting of a broad Fe K\u03b1 line and the Compton reflection hump, reveals that the black hole is rapidly spinning with the spin parameter of a* > 0.96, and the inner accretion disk is viewed at a high inclination angle of I = 64^(2 o)_(-3) (statistical errors, 90% confidence). The high inclination is independently confirmed by dips in the light curves, which can be explained by absorbing material located near the disk plane temporarily obscuring the central region. In addition, we detect an absorption line in the NuSTAR spectra centered at 7.03^(+0.04)_(-0.03) keV. If associated with ionized Fe K absorption lines, this provides evidence for the presence of outflowing material in the low/hard state of a black hole binary candidate. A timing analysis shows the presence of a type-C quasi-periodic oscillation in the power spectrum, with the frequency increasing from ~0.14 to ~0.21 Hz during the single NuSTAR exposure. Our analysis reveals that Swift J1658.2\u20134242 displays characteristics typical for a black hole binary that is viewed at a high inclination angle, making it a good system for studying the accretion geometry in black hole binaries.", "doi": "10.3847/1538-4357/aada03", "issn": "1538-4357", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2018-09-20", "series_number": "1", "volume": "865", "issue": "1", "pages": "Art. No. 18" }, { "id": "authors:s5wbk-tyh04", "collection": "authors", "collection_id": "s5wbk-tyh04", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180829-161431338", "type": "article", "title": "Carbon X-ray absorption in the local ISM: Fingerprintsin X-ray Novae spectra", "author": [ { "family_name": "Gatuzz", "given_name": "Efra\u00edn", "orcid": "0000-0002-3252-9633", "clpid": "Gatuzz-E" }, { "family_name": "Ness", "given_name": "J.-U.", "clpid": "Ness-J-U" }, { "family_name": "Gorczyca", "given_name": "T. W.", "clpid": "Gorczyca-T-W" }, { "family_name": "Hasoglu", "given_name": "M. F.", "clpid": "Hasoglu-M-F" }, { "family_name": "Kallman", "given_name": "Timothy R.", "orcid": "0000-0002-5779-6906", "clpid": "Kallman-Timothy-R" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" } ], "abstract": "We present a study of the C K-edge using high-resolution LETGS Chandraspectra of four novae during their super-soft-source (SSS) phase. We identified absorption lines due to C II K\u03b1, C III K\u03b1, and C III K\u03b2 resonances. We used these astronomical observations to perform a benchmarking of the atomic data, which involves wavelength shifts of the resonances and photoionization cross-sections. We used improved atomic data to estimate the C II and C III column densities. The absence of physical shifts for the absorption lines, the consistence of the column densities between multiple observations, and the high temperature required for the SSS nova atmosphere modelling support our conclusion about an interstellar medium origin of the respective absorption lines. Assuming a collisional ionization equilibrium plasma the maximum temperature derived from the ratio of C II/C III column densities of the absorbers correspond to T_(max) < 3.05 \u00d7 10^4 K.", "doi": "10.1093/mnras/sty1517", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2018-09-11", "series_number": "2", "volume": "479", "issue": "2", "pages": "2457-2463" }, { "id": "authors:ajyj5-bw704", "collection": "authors", "collection_id": "ajyj5-bw704", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180827-144724340", "type": "article", "title": "Reflection Spectroscopy of the Black Hole Binary XTE J1752\u2212223 in Its Long-stable Hard State", "author": [ { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Steiner", "given_name": "James F.", "orcid": "0000-0002-5872-6061", "clpid": "Steiner-J-F" }, { "family_name": "Grinberg", "given_name": "Victoria", "orcid": "0000-0003-2538-0188", "clpid": "Grinberg-V" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-T" }, { "family_name": "Connors", "given_name": "Riley M. T.", "orcid": "0000-0002-8908-759X", "clpid": "Connors-R-M-T" }, { "family_name": "McClintock", "given_name": "Jeffrey E.", "clpid": "McClintock-J-E" }, { "family_name": "Remillard", "given_name": "Ronald A.", "orcid": "0000-0003-4815-0481", "clpid": "Remillard-R-A" }, { "family_name": "Wilms", "given_name": "J\u00f6rn", "orcid": "0000-0003-2065-5410", "clpid": "Wilms-J" }, { "family_name": "Harrison", "given_name": "Fiona A.", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" }, { "family_name": "Tomsick", "given_name": "John A.", "orcid": "0000-0001-5506-9855", "clpid": "Tomsick-J-A" } ], "abstract": "We present a detailed spectral analysis of the black hole binary XTE J1752\u2212223 in the hard state of its 2009 outburst. Regular monitoring of this source by the Rossi X-ray Timing Explorer mission provided high signal-to-noise spectra along the outburst rise and decay. During one full month this source stalled at ~30% of its peak count rate at a constant hardness and intensity. By combining all the data in this exceptionally stable hard state, we obtained an aggregate proportional counter array spectrum (3\u201345 keV) with 100 million counts, and a corresponding high energy X-ray timing experiment spectrum (20\u2013140 keV) with 5.8 million counts. Implementing a version of our reflection code with a physical model for Comptonization, we obtain tight constraints on important physical parameters for this system. In particular, the inner accretion disk is measured very close in, at R_(in) = 1.7 \u00b1 0.4 R_g . Assuming R_(in_ = R_(ISCO), we find a relatively high black hole spin (a_* = 0.92 \u00b1 0.06). Imposing a lamppost geometry, we obtain a low inclination (i = 35\u00b0 \u00b1 4\u00b0), which agrees with the upper limit found in the radio (i < 49\u00b0). However, we note that this model cannot be statistically distinguished from a non-lamppost model with a free emissivity index, for which the inclination is markedly higher. Additionally, we find a relatively cool corona (57\u201370 keV) and large iron abundance (3.3\u20133.7 solar). We further find that properly accounting for Comptonization of the reflection emission improves the fit significantly and causes an otherwise low reflection fraction (~0.2\u20130.3) to increase by an order of magnitude, in line with geometrical expectations for a lamppost corona. We compare these results with similar investigations reported for GX 339\u22124 in its bright hard state.", "doi": "10.3847/1538-4357/aad231", "issn": "1538-4357", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2018-09-01", "series_number": "1", "volume": "864", "issue": "1", "pages": "Art. No. 25" }, { "id": "authors:zyewb-xrc17", "collection": "authors", "collection_id": "zyewb-xrc17", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180620-154958509", "type": "article", "title": "The 1.5\u2009Ms observing campaign on IRAS 13224\u22123809 \u2013 I. X-ray spectral analysis", "author": [ { "family_name": "Jiang", "given_name": "J.", "orcid": "0000-0002-8796-5846", "clpid": "Jiang-Junle" }, { "family_name": "Parker", "given_name": "M. L.", "orcid": "0000-0002-8466-7317", "clpid": "Parker-M-L" }, { "family_name": "Fabian", "given_name": "A. C.", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-A-C" }, { "family_name": "Alston", "given_name": "W. N.", "orcid": "0000-0003-2658-6559", "clpid": "Alston-W-N" }, { "family_name": "Buisson", "given_name": "D. J. K.", "clpid": "Buisson-D-J-K" }, { "family_name": "Cackett", "given_name": "E. M.", "orcid": "0000-0002-8294-9281", "clpid": "Cackett-E-M" }, { "family_name": "Chiang", "given_name": "C.-Y.", "orcid": "0000-0002-9630-4003", "clpid": "Chiang-Chia-Ying" }, { "family_name": "Dauser", "given_name": "T.", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-T" }, { "family_name": "Gallo", "given_name": "L. C.", "clpid": "Gallo-L-C" }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Harrison", "given_name": "F. A.", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" }, { "family_name": "Lohfink", "given_name": "A. M.", "clpid": "Lohfink-A-M" }, { "family_name": "De Marco", "given_name": "B.", "clpid": "De-Marco-B" }, { "family_name": "Kara", "given_name": "E.", "orcid": "0000-0003-0172-0854", "clpid": "Kara-E" }, { "family_name": "Miller", "given_name": "J. M.", "clpid": "Miller-J-M" }, { "family_name": "Miniutti", "given_name": "G.", "clpid": "Miniutti-G" }, { "family_name": "Pinto", "given_name": "C.", "orcid": "0000-0003-2532-7379", "clpid": "Pinto-C" }, { "family_name": "Walton", "given_name": "D. J.", "orcid": "0000-0001-5819-3552", "clpid": "Walton-D-J" }, { "family_name": "Wilkins", "given_name": "D. R.", "clpid": "Wilkins-D-R" } ], "abstract": "We present a detailed spectral analysis of the recent 1.5\u2009Ms XMM\u2013Newton observing campaign on the narrow-line Seyfert 1 galaxy IRAS 13224\u22123809, taken simultaneously with 500\u2009ks of NuSTAR data. The X-ray light curve shows three flux peaks, registering at about 100 times the minimum flux seen during the campaign, and rapid variability with a time-scale of kiloseconds. The spectra are well fit with a primary power-law continuum, two relativistic-blurred reflection components from the inner accretion disc with very high iron abundance, and a simple blackbody-shaped model for the remaining soft excess. The spectral variability is dominated by the power-law continuum from a corona region within a few gravitational radii from the black hole. Additionally, blueshifted Ne\u2009X, Mg\u2009XII, Si\u2009XIV, and S\u2009XVI absorption lines are identified in the stacked low-flux spectrum, confirming the presence of a highly ionized outflow with velocity up to v = 0.267 and 0.225\u2009c. We fit the absorption features with xstar models and find a relatively constant velocity outflow through the whole observation. Finally, we replace the bbody and supersolar abundance reflection models by fitting the soft excess successfully with the extended reflection model relxillD, which allows for higher densities than the standard relxill model. This returns a disc electron density n_e > 10^(18.7)\u2009cm^(\u22123) and lowers the iron abundance from Z_(Fe) = 24^(+3)_(\u22124)Z_\u2299 with n-e = 10^(15) cm^(-3) to Z_(Fe) = 6.6^(+0.8)_(-2.1)Z_\u2299.", "doi": "10.1093/mnras/sty836", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2018-07-01", "series_number": "3", "volume": "477", "issue": "3", "pages": "3711-3726" }, { "id": "authors:qvbkk-ddk82", "collection": "authors", "collection_id": "qvbkk-ddk82", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180503-130325076", "type": "article", "title": "Detection of Reflection Features in the Neutron Star Low-mass X-Ray Binary Serpens X-1 with NICER", "author": [ { "family_name": "Ludlam", "given_name": "R. M.", "orcid": "0000-0002-8961-939X", "clpid": "Ludlam-R-M" }, { "family_name": "Miller", "given_name": "J. M.", "clpid": "Miller-J-M" }, { "family_name": "Arzoumanian", "given_name": "Z.", "clpid": "Arzoumanian-Z" }, { "family_name": "Bult", "given_name": "P. M.", "clpid": "Bult-P-M" }, { "family_name": "Cackett", "given_name": "E. M.", "orcid": "0000-0002-8294-9281", "clpid": "Cackett-E-M" }, { "family_name": "Chakrabarty", "given_name": "D.", "orcid": "0000-0001-8804-8946", "clpid": "Chakrabarty-D" }, { "family_name": "Dauser", "given_name": "T.", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-T" }, { "family_name": "Enoto", "given_name": "T.", "orcid": "0000-0003-1244-3100", "clpid": "Enoto-Teruaki" }, { "family_name": "Fabian", "given_name": "A. C.", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-A-C" }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Gendreau", "given_name": "K. C.", "clpid": "Gendreau-K-C" }, { "family_name": "Guillot", "given_name": "S.", "orcid": "0000-0002-6449-106X", "clpid": "Guillot-S" }, { "family_name": "Homan", "given_name": "J.", "orcid": "0000-0001-8371-2713", "clpid": "Homan-J" }, { "family_name": "Jaisawal", "given_name": "G. K.", "orcid": "0000-0002-6789-2723", "clpid": "Jaisawal-G-K" }, { "family_name": "Keek", "given_name": "L.", "clpid": "Keek-L" }, { "family_name": "La Marr", "given_name": "B.", "clpid": "La-Marr-B" }, { "family_name": "Malacaria", "given_name": "C.", "orcid": "0000-0002-0380-0041", "clpid": "Malacaria-C" }, { "family_name": "Markwardt", "given_name": "C. B.", "orcid": "0000-0001-9803-3879", "clpid": "Markwardt-C-B" }, { "family_name": "Steiner", "given_name": "J. F.", "orcid": "0000-0002-5872-6061", "clpid": "Steiner-J-F" }, { "family_name": "Strohmayer", "given_name": "T. E.", "orcid": "0000-0001-7681-5845", "clpid": "Strohmayer-T-E" } ], "abstract": "We present Neutron Star Interior Composition Explorer (NICER) observations of the neutron star (NS) low-mass X-ray binary Serpens X-1 during the early mission phase in 2017. With the high spectral sensitivity and low-energy X-ray passband of NICER, we are able to detect the Fe L line complex in addition to the signature broad, asymmetric Fe K line. We confirm the presence of these lines by comparing the NICER data to archival observations with XMM-Newton/Reflection Grating Spectrometer (RGS) and NuSTAR. Both features originate close to the innermost stable circular orbit (ISCO). When modeling the lines with the relativistic line model RELLINE, we find that the Fe L blend requires an inner disk radius of 1.4^(+0.2)_(-0.1) R_(ISCO) and Fe K is at 1.03^(+0.13)_(-0.03) R_(ISCO) (errors quoted at 90%). This corresponds to a position of 17.3^(+2.5)_(-1.2) km and 12.7^(+1.6)_(-0.4) km for a canonical NS mass (M_(NS) = 1.4 M\u2299) and dimensionless spin value of a = 0. Additionally, we employ a new version of the RELXILL model tailored for NSs and determine that these features arise from a dense disk and supersolar Fe abundance.", "doi": "10.3847/2041-8213/aabee6", "issn": "2041-8213", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal Letters", "publication_date": "2018-05-01", "series_number": "1", "volume": "858", "issue": "1", "pages": "Art. No. L5" }, { "id": "authors:x4xvs-fcf10", "collection": "authors", "collection_id": "x4xvs-fcf10", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180329-144301332", "type": "article", "title": "Is there a UV/X-ray connection in IRAS 13224\u22123809?", "author": [ { "family_name": "Buisson", "given_name": "D. J. K.", "clpid": "Buisson-D-J-K" }, { "family_name": "Lohfink", "given_name": "A. M.", "clpid": "Lohfink-A-M" }, { "family_name": "Alston", "given_name": "W. N.", "orcid": "0000-0003-2658-6559", "clpid": "Alston-W-N" }, { "family_name": "Cackett", "given_name": "E. M.", "orcid": "0000-0002-8294-9281", "clpid": "Cackett-E-M" }, { "family_name": "Chiang", "given_name": "C.-Y.", "orcid": "0000-0002-9630-4003", "clpid": "Chiang-Chia-Ying" }, { "family_name": "Dauser", "given_name": "T.", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-T" }, { "family_name": "De Marco", "given_name": "B.", "clpid": "De-Marco-B" }, { "family_name": "Fabian", "given_name": "A. C.", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-A-C" }, { "family_name": "Gallo", "given_name": "L. C.", "clpid": "Gallo-L-C" }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Jiang", "given_name": "J.", "orcid": "0000-0002-8796-5846", "clpid": "Jiang-Junle" }, { "family_name": "Kara", "given_name": "E.", "orcid": "0000-0003-0172-0854", "clpid": "Kara-E" }, { "family_name": "Middleton", "given_name": "M. J.", "orcid": "0000-0002-8183-2970", "clpid": "Middleton-M-J" }, { "family_name": "Miniutti", "given_name": "G.", "clpid": "Miniutti-G" }, { "family_name": "Parker", "given_name": "M. L.", "orcid": "0000-0002-8466-7317", "clpid": "Parker-M-L" }, { "family_name": "Pinto", "given_name": "C.", "orcid": "0000-0003-2532-7379", "clpid": "Pinto-C" }, { "family_name": "Uttley", "given_name": "P.", "clpid": "Uttley-P" }, { "family_name": "Walton", "given_name": "D. J.", "orcid": "0000-0001-5819-3552", "clpid": "Walton-D-J" }, { "family_name": "Wilkins", "given_name": "D. R.", "clpid": "Wilkins-D-R" } ], "abstract": "We present results from the optical, ultraviolet, and X-ray monitoring of the NLS1 galaxy IRAS 13224\u22123809 taken with Swift and XMM\u2013Newton during 2016. IRAS 13224\u22123809 is the most variable bright AGN in the X-ray sky and shows strong X-ray reflection, implying that the X-rays strongly illuminate the inner disc. Therefore, it is a good candidate to study the relationship between coronal X-ray and disc UV emission. However, we find no correlation between the X-ray and UV flux over the available \u223c40\u2009d monitoring, despite the presence of strong X-ray variability and the variable part of the UV spectrum being consistent with irradiation of a standard thin disc. This means either that the X-ray flux which irradiates the UV emitting outer disc does not correlate with the X-ray flux in our line of sight and/or that another process drives the majority of the UV variability. The former case may be due to changes in coronal geometry, absorption or scattering between the corona and the disc.", "doi": "10.1093/mnras/sty008", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2018-04-01", "series_number": "2", "volume": "475", "issue": "2", "pages": "2306-2313" }, { "id": "authors:5kgmy-rfa06", "collection": "authors", "collection_id": "5kgmy-rfa06", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180227-133907106", "type": "article", "title": "Alternative Explanations for Extreme Supersolar Iron Abundances Inferred from the Energy Spectrum of Cygnus X-1", "author": [ { "family_name": "Tomsick", "given_name": "John A.", "orcid": "0000-0001-5506-9855", "clpid": "Tomsick-J-A" }, { "family_name": "Parker", "given_name": "Michael L.", "orcid": "0000-0002-8466-7317", "clpid": "Parker-M-L" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Yamaoka", "given_name": "Kazutaka", "clpid": "Yamaoka-Kazutaka" }, { "family_name": "Barret", "given_name": "Didier", "orcid": "0000-0002-0393-9190", "clpid": "Barret-D" }, { "family_name": "Chiu", "given_name": "Jeng-Lun", "clpid": "Chiu-Jeng-Lun" }, { "family_name": "Clavel", "given_name": "Ma\u00efca", "orcid": "0000-0003-0724-2742", "clpid": "Clavel-M" }, { "family_name": "Fabian", "given_name": "Andrew", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-A-C" }, { "family_name": "F\u00fcrst", "given_name": "Felix", "orcid": "0000-0003-0388-0560", "clpid": "F\u00fcrst-F" }, { "family_name": "Gandhi", "given_name": "Poshak", "orcid": "0000-0003-3105-2615", "clpid": "Gandhi-Poshak" }, { "family_name": "Grinberg", "given_name": "Victoria", "orcid": "0000-0003-2538-0188", "clpid": "Grinberg-V" }, { "family_name": "Miller", "given_name": "Jon M.", "clpid": "Miller-J-M" }, { "family_name": "Pottschmidt", "given_name": "Katja", "orcid": "0000-0002-4656-6881", "clpid": "Pottschmidt-K" }, { "family_name": "Walton", "given_name": "Dominic J.", "orcid": "0000-0001-5819-3552", "clpid": "Walton-D-J" } ], "abstract": "Here we study a 1\u2013200 keV energy spectrum of the black hole binary Cygnus X-1 taken with NuSTAR and Suzaku. This is the first report of a NuSTAR observation of Cyg X-1 in the intermediate state, and the observation was taken during the part of the binary orbit where absorption due to the companion's stellar wind is minimal. The spectrum includes a multi-temperature thermal disk component, a cutoff power-law component, and relativistic and nonrelativistic reflection components. Our initial fits with publicly available constant density reflection models (relxill and reflionx) lead to extremely high iron abundances (>9.96 and 10.6_(-0.9)^(+1.6) times solar, respectively). Although supersolar iron abundances have been reported previously for Cyg X-1, our measurements are much higher and such variability is almost certainly unphysical. Using a new version of reflionx that we modified to make the electron density a free parameter, we obtain better fits to the spectrum even with solar iron abundances. We report on how the higher density (n_e = (3.98)_(-0.25)^(+0.12)) x 10^(20) cm^(\u22123)) impacts other parameters such as the inner radius and inclination of the disk.", "doi": "10.3847/1538-4357/aaaab1", "issn": "1538-4357", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2018-03-01", "series_number": "1", "volume": "855", "issue": "1", "pages": "Art. No. 3" }, { "id": "authors:0ewab-36g27", "collection": "authors", "collection_id": "0ewab-36g27", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180308-105914434", "type": "article", "title": "The Evolution of GX 339-4 in the Low-hard State as Seen by NuSTAR and Swift", "author": [ { "family_name": "Wang-Ji", "given_name": "Jingyi", "clpid": "Wang-Ji-Jingyi" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Steiner", "given_name": "James F.", "orcid": "0000-0002-5872-6061", "clpid": "Steiner-J-F" }, { "family_name": "Tomsick", "given_name": "John A.", "orcid": "0000-0001-5506-9855", "clpid": "Tomsick-J-A" }, { "family_name": "Harrison", "given_name": "Fiona A.", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" }, { "family_name": "Bambi", "given_name": "Cosimo", "orcid": "0000-0002-3180-9502", "clpid": "Bambi-C" }, { "family_name": "Petrucci", "given_name": "Pierre-Olivier", "clpid": "Petrucci-Pierre-Olivier" }, { "family_name": "Ferreira", "given_name": "Jonathan", "clpid": "Ferreira-J" }, { "family_name": "Chakravorty", "given_name": "Susmita", "clpid": "Chakravorty-S" }, { "family_name": "Clavel", "given_name": "Ma\u00efca", "orcid": "0000-0003-0724-2742", "clpid": "Clavel-M" } ], "abstract": "We analyze 11 Nuclear Spectroscopic Telescope Array and Swift observations of the black hole X-ray binary GX 339\u20134 in the hard state, 6 of which were taken during the end of the 2015 outburst and 5 during a failed outburst in 2013. These observations cover luminosities from 0.5% to 5% of the Eddington luminosity. Implementing the most recent version of the reflection model relxillCp, we perform simultaneous spectral fits on both data sets to track the evolution of the properties in the accretion disk, including the inner edge radius, the ionization, and the temperature of the thermal emission. We also constrain the photon index and electron temperature of the primary source (the \"corona\"). We observe a maximum truncation radius of 37 R_g in the preferred fit for the 2013 data set, and a marginal correlation between the level of truncation and luminosity. We also explore a self-consistent model under the framework of coronal Comptonization, and find consistent results regarding the disk truncation in the 2015 data, providing a more physical preferred fit for the 2013 observations.", "doi": "10.3847/1538-4357/aaa974", "issn": "1538-4357", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2018-03-01", "series_number": "1", "volume": "855", "issue": "1", "pages": "Art. No. 61" }, { "id": "authors:ej271-v3g22", "collection": "authors", "collection_id": "ej271-v3g22", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180202-085648382", "type": "article", "title": "Testing General Relativity with the Reflection Spectrum of the Supermassive Black Hole in 1H0707-495", "author": [ { "family_name": "Cao", "given_name": "Zheng", "clpid": "Cao-Zheng" }, { "family_name": "Nampalliwar", "given_name": "Sourabh", "clpid": "Nampalliwar-S" }, { "family_name": "Bambi", "given_name": "Cosimo", "orcid": "0000-0002-3180-9502", "clpid": "Bambi-C" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-T" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" } ], "abstract": "Recently, we have extended the x-ray reflection model RELXILL to test the spacetime metric in the strong gravitational field of astrophysical black holes. In the present Letter, we employ this extended model to analyze XMM-Newton, NuSTAR, and Swift data of the supermassive black hole in 1H0707-495 and test deviations from a Kerr metric parametrized by the Johannsen deformation parameter \u03b1_(13). Our results are consistent with the hypothesis that the spacetime metric around the black hole in 1H0707-495 is described by the Kerr solution.", "doi": "10.1103/PhysRevLett.120.051101", "issn": "0031-9007", "publisher": "American Physical Society", "publication": "Physical Review Letters", "publication_date": "2018-02-02", "series_number": "5", "volume": "120", "issue": "5", "pages": "Art. No. 051101" }, { "id": "authors:9mtkt-sa928", "collection": "authors", "collection_id": "9mtkt-sa928", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180116-152713791", "type": "article", "title": "Reflection Spectra of the Black Hole Binary Candidate MAXI J1535-571 in the Hard State Observed by NuSTAR", "author": [ { "family_name": "Xu", "given_name": "Yanjun", "orcid": "0000-0003-2443-3698", "clpid": "Xu-Yanjun" }, { "family_name": "Harrison", "given_name": "Fiona A.", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Fabian", "given_name": "Andrew C.", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-A-C" }, { "family_name": "F\u00fcrst", "given_name": "Felix", "orcid": "0000-0003-0388-0560", "clpid": "F\u00fcrst-F" }, { "family_name": "Gandhi", "given_name": "Poshak", "orcid": "0000-0003-3105-2615", "clpid": "Gandhi-Poshak" }, { "family_name": "Grefenstette", "given_name": "Brian W.", "orcid": "0000-0002-1984-2932", "clpid": "Grefenstette-B-W" }, { "family_name": "Madsen", "given_name": "Kristin K.", "orcid": "0000-0003-1252-4891", "clpid": "Madsen-K-K" }, { "family_name": "Miller", "given_name": "Jon M.", "clpid": "Miller-J-M" }, { "family_name": "Parker", "given_name": "Michael L.", "orcid": "0000-0002-8466-7317", "clpid": "Parker-M-L" }, { "family_name": "Tomsick", "given_name": "John A.", "orcid": "0000-0001-5506-9855", "clpid": "Tomsick-J-A" }, { "family_name": "Walton", "given_name": "Dominic J.", "orcid": "0000-0001-5819-3552", "clpid": "Walton-D-J" } ], "abstract": "We report on a Nuclear Spectroscopic Telescope Array (NuSTAR) observation of the recently discovered bright black hole candidate MAXI J1535-571. NuSTAR observed the source on MJD 58003 (five days after the outburst was reported). The spectrum is characteristic of a black hole binary in the hard state. We observe clear disk reflection features, including a broad Fe K\u03b1 line and a Compton hump peaking around 30 keV. Detailed spectral modeling reveals a narrow Fe K\u03b1 line complex centered around 6.5 keV on top of the strong relativistically broadened Fe K\u03b1 line. The narrow component is consistent with distant reflection from moderately ionized material. The spectral continuum is well described by a combination of cool thermal disk photons and a Comptonized plasma with the electron temperature kT_e = 19.7 \u00b1 0.4 keV. An adequate fit can be achieved for the disk reflection features with a self-consistent relativistic reflection model that assumes a lamp-post geometry for the coronal illuminating source. The spectral fitting measures a black hole spin a > 0.84, inner disk radius R_(in) < 2.01 r_(ISCO) , and a lamp-post height h = 7.2^(+0.8)_(-2.0) r_g (statistical errors, 90% confidence), indicating no significant disk truncation and a compact corona. Although the distance and mass of this source are not currently known, this suggests the source was likely in the brighter phases of the hard state during this NuSTAR observation.", "doi": "10.3847/2041-8213/aaa4b2", "issn": "2041-8213", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal Letters", "publication_date": "2018-01-10", "series_number": "2", "volume": "852", "issue": "2", "pages": "Art. No. L34" }, { "id": "authors:0mj2j-kdd35", "collection": "authors", "collection_id": "0mj2j-kdd35", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180125-144741618", "type": "article", "title": "A deep X-ray view of the bare AGN Ark 120. IV. XMM-Newton and NuSTAR spectra dominated by two temperature (warm, hot) Comptonization processes", "author": [ { "family_name": "Porquet", "given_name": "D.", "orcid": "0000-0001-9731-0352", "clpid": "Porquet-D" }, { "family_name": "Reeves", "given_name": "J. N.", "clpid": "Reeves-J-N" }, { "family_name": "Matt", "given_name": "G.", "orcid": "0000-0002-2152-0916", "clpid": "Matt-G" }, { "family_name": "Marinucci", "given_name": "A.", "clpid": "Marinucci-A" }, { "family_name": "Nardini", "given_name": "E.", "orcid": "0000-0001-9226-8992", "clpid": "Nardini-E" }, { "family_name": "Braito", "given_name": "V.", "orcid": "0000-0002-2629-4989", "clpid": "Braito-V" }, { "family_name": "Lobban", "given_name": "A.", "orcid": "0000-0002-6433-1357", "clpid": "Lobban-A-P" }, { "family_name": "Ballantyne", "given_name": "D. R.", "orcid": "0000-0001-8128-6976", "clpid": "Ballantyne-D-R" }, { "family_name": "Boggs", "given_name": "S. E.", "orcid": "0000-0001-9567-4224", "clpid": "Boggs-S-E" }, { "family_name": "Christensen", "given_name": "F. E.", "orcid": "0000-0001-5679-1946", "clpid": "Christensen-F-E" }, { "family_name": "Dauser", "given_name": "T.", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-T" }, { "family_name": "Farrah", "given_name": "D.", "orcid": "0000-0003-1748-2010", "clpid": "Farrah-D" }, { "family_name": "Garc\u00eda", "given_name": "J.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Hailey", "given_name": "C. J.", "clpid": "Hailey-C-J" }, { "family_name": "Harrison", "given_name": "F.", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" }, { "family_name": "Stern", "given_name": "D.", "orcid": "0000-0003-2686-9241", "clpid": "Stern-D" }, { "family_name": "Tortosa", "given_name": "A.", "clpid": "Tortosa-A" }, { "family_name": "Ursini", "given_name": "F.", "clpid": "Ursini-F" }, { "family_name": "Zhang", "given_name": "W. W.", "orcid": "0000-0002-1426-9698", "clpid": "Zhang-W-W" } ], "abstract": "Context. The physical characteristics of the material closest to supermassive black holes (SMBHs) are primarily studied through X-ray observations. However, the origins of the main X-ray components such as the soft X-ray excess, the Fe\u2009K\u03b1 line complex, and the hard X-ray excess are still hotly debated. This is particularly problematic for active galactic nuclei (AGN) showing a significant intrinsic absorption, either warm or neutral, which can severely distort the observed continuum. Therefore, AGN with no (or very weak) intrinsic absorption along the line of sight, so-called \"bare AGN\", are the best targets to directly probe matter very close to the SMBH.\nAims. We perform an X-ray spectral analysis of the brightest and cleanest bare AGN known so far, Ark\u2009120, in order to determine the process(es) at work in the vicinity of the SMBH.\nMethods. We present spectral analyses of data from an extensive campaign observing Ark\u2009120 in X-rays with XMM-Newton (4 \u00d7 120\u2009ks, 2014 March 18\u201324), and NuSTAR (65.5\u2009ks, 2014 March 22).\nResults. During this very deep X-ray campaign, the source was caught in a high-flux state similar to the earlier 2003 XMM-Newton observation, and about twice as bright as the lower-flux observation in 2013. The spectral analysis confirms the \"softer when brighter\" behavior of Ark\u2009120. The four XMM-Newton/pn spectra are characterized by the presence of a prominent soft X-ray excess and a significant Fe\u2009K\u03b1 complex. The continuum is very similar above about 3\u2009keV, while significant variability is present for the soft X-ray excess. We find that relativistic reflection from a constant-density, flat accretion disk cannot simultaneously produce the soft excess, broad Fe\u2009K\u03b1 complex, and hard X-ray excess. Instead, Comptonization reproduces the broadband (0.3\u201379 keV) continuum well, together with a contribution from a mildly relativistic disk reflection spectrum.\nConclusions. During this 2014 observational campaign, the soft X-ray spectrum of Ark 120 below ~0.5\u2009keV was found to be dominated by Comptonization of seed photons from the disk by a warm (kTe ~ 0.5\u2009keV), optically-thick corona (\u03c4 ~ 9). Above this energy, the X-ray spectrum becomes dominated by Comptonization from electrons in a hot optically thin corona, while the broad Fe\u2009K\u03b1 line and the mild Compton hump result from reflection off the disk at several tens of gravitational radii.", "doi": "10.1051/0004-6361/201731290", "issn": "0004-6361", "publisher": "EDP Sciences", "publication": "Astronomy and Astrophysics", "publication_date": "2018-01", "volume": "609", "pages": "Art. No. A42" }, { "id": "authors:6n6jz-n4y92", "collection": "authors", "collection_id": "6n6jz-n4y92", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180906-133850023", "type": "book_section", "title": "The Problem of the High Iron Abundance in Accretion Disks around Black Holes", "book_title": "Workshop on Astrophysical Opacities", "author": [ { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Kallman", "given_name": "T. R.", "orcid": "0000-0002-5779-6906", "clpid": "Kallman-Timothy-R" }, { "family_name": "Bautista", "given_name": "M.", "clpid": "Bautista-Manuel" }, { "family_name": "Mendoza", "given_name": "C.", "clpid": "Mendoza-C" }, { "family_name": "Deprince", "given_name": "J.", "orcid": "0000-0002-3409-8232", "clpid": "Deprince-J\u00e9r\u00f4me" }, { "family_name": "Palmeri", "given_name": "P.", "clpid": "Palmeri-P" }, { "family_name": "Quinet", "given_name": "P.", "clpid": "Quinet-P" } ], "contributor": [ { "family_name": "Mendoza", "given_name": "Claudio", "clpid": "Mendoza-C" }, { "family_name": "Turck-Chi\u00e8ze", "given_name": "Sylvaine", "clpid": "Turck-Chi\u00e8ze-S" }, { "family_name": "Colgan", "given_name": "James", "clpid": "Colgan-J" } ], "abstract": "In most accreting black-hole systems the copious X-rays commonly observed from the inner-most regions are accompanied by a reflection spectrum. The latter is the signature of energetic photons reprocessed by the optically thick material of an accretion disk. Given their abundance and fluorescence yield, the iron K-shell lines are the most prominent features in the X-ray reflected spectrum. Their line profiles can be grossly broadened and skewed by Doppler effects and gravitational redshift. Consequently, modeling the reflection spectrum provides one of the best methods to measure, among other physical quantities, the black-hole spin. At present the accuracy of the spin estimates is called into question because the data fits require very high iron abundances: typically several times the solar value. No plausible physical explanation has been concurrently proffered for these black-hole systems to be so iron rich. The most likely explanation for the supersolar iron abundances is model shortfall at very high densities (>10^(18) cm^(\u20133)) due to atomic data shortcomings in this regime. We review the current observational evidence for the iron supersolar abundance in many black-hole systems, and show the effects of high density in state-of-the-art reflection models. We also briefly discuss our current efforts to produce new atomic data for high-density plasmas, which are required to refine the photoionization models.", "doi": "10.48550/arXiv.1805.00581", "isbn": "978-1-58381-914-2", "publisher": "Astronomical Society of the Pacific", "place_of_publication": "San Francisco, CA", "publication_date": "2018", "pages": "282-288" }, { "id": "authors:ps2bj-2cg36", "collection": "authors", "collection_id": "ps2bj-2cg36", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180906-134808098", "type": "book_section", "title": "Plasma-Environment Effects on the Atomic Structure and K Lines of He- and Li-like Oxygen Ions", "book_title": "Workshop on Astrophysical Opacities", "author": [ { "family_name": "Deprince", "given_name": "J.", "orcid": "0000-0002-3409-8232", "clpid": "Deprince-J\u00e9r\u00f4me" }, { "family_name": "Palmeri", "given_name": "P.", "clpid": "Palmeri-P" }, { "family_name": "Quinet", "given_name": "P.", "clpid": "Quinet-P" }, { "family_name": "Fritzsche", "given_name": "S.", "clpid": "Fritzsche-Stephan" }, { "family_name": "Bautista", "given_name": "M.", "clpid": "Bautista-Manuel" }, { "family_name": "Mendoza", "given_name": "C.", "clpid": "Mendoza-C" }, { "family_name": "Kallman", "given_name": "T. R.", "orcid": "0000-0002-5779-6906", "clpid": "Kallman-Timothy-R" }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" } ], "contributor": [ { "family_name": "Mendoza", "given_name": "Claudio", "clpid": "Mendoza-C" }, { "family_name": "Turck-Chi\u00e8ze", "given_name": "Sylvaine", "clpid": "Turck-Chi\u00e8ze-S" }, { "family_name": "Colgan", "given_name": "James", "clpid": "Colgan-J" } ], "abstract": "In the context of black-hole accretion disks, we estimate the effects of the plasma environment on the atomic parameters associated with K-vacancy states in He- and Li-like oxygen ions. Multiconfiguration Dirac\u2013Fock and Breit\u2013Pauli computations have been carried out assuming a time-averaged Debye\u2013H\u00fcckel potential for both the electron\u2013nucleus and electron\u2013electron interactions. Plasma effects on the ionization and excitation thresholds, transition wavelengths, and radiative emission rates are reported for O VI and O VII.", "isbn": "978-1-58381-914-2", "publisher": "Astronomical Society of the Pacific", "place_of_publication": "San Francisco, CA", "publication_date": "2018", "pages": "289-294" }, { "id": "authors:6vcch-hm513", "collection": "authors", "collection_id": "6vcch-hm513", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20171004-130639886", "type": "article", "title": "Swift and NuSTAR observations of GW170817: detection of a blue kilonova", "author": [ { "family_name": "Evans", "given_name": "P. A.", "orcid": "0000-0002-8465-3353", "clpid": "Evans-P-A" }, { "family_name": "Madsen", "given_name": "K. K.", "orcid": "0000-0003-1252-4891", "clpid": "Madsen-K-K" }, { "family_name": "Harrison", "given_name": "F. A.", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" }, { "family_name": "Xu", "given_name": "Y.", "orcid": "0000-0003-2443-3698", "clpid": "Xu-Yanjun" }, { "family_name": "Forster", "given_name": "K.", "orcid": "0000-0001-5800-5531", "clpid": "Forster-K" }, { "family_name": "Garc\u00eda", "given_name": "J.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Grefenstette", "given_name": "B.", "orcid": "0000-0002-1984-2932", "clpid": "Grefenstette-B-W" }, { "family_name": "Heida", "given_name": "M.", "orcid": "0000-0002-1082-7496", "clpid": "Heida-M" }, { "family_name": "Miyasaka", "given_name": "H.", "orcid": "0000-0002-8074-4186", "clpid": "Miyasaka-Hiromasa" }, { "family_name": "Pike", "given_name": "S.", "orcid": "0000-0002-8403-0041", "clpid": "Pike-S-N" }, { "family_name": "Rosswog", "given_name": "S.", "clpid": "Rosswog-S" } ], "abstract": "With the first direct detection of merging black holes in 2015, the era of gravitational wave (GW) astrophysics began. A complete picture of compact object mergers, however, requires the detection of an electromagnetic (EM) counterpart. We report ultraviolet (UV) and x-ray observations by Swift and the Nuclear Spectroscopic Telescope Array of the EM counterpart of the binary neutron star merger GW170817. The bright, rapidly fading UV emission indicates a high mass (\u22480.03 solar masses) wind-driven outflow with moderate electron fraction (Ye \u2248 0.27). Combined with the x-ray limits, we favor an observer viewing angle of \u224830\u00b0 away from the orbital rotation axis, which avoids both obscuration from the heaviest elements in the orbital plane and a direct view of any ultrarelativistic, highly collimated ejecta (a \u03b3-ray burst afterglow).", "doi": "10.1126/science.aap9580", "issn": "0036-8075", "publisher": "American Association for the Advancement of Science", "publication": "Science", "publication_date": "2017-12-22", "series_number": "6370", "volume": "358", "issue": "6370", "pages": "1565-1570" }, { "id": "authors:xz4fh-5c285", "collection": "authors", "collection_id": "xz4fh-5c285", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20171219-092934959", "type": "article", "title": "Spectral and Timing Properties of IGR J17091\u20133624 in the Rising Hard State During Its 2016 Outburst", "author": [ { "family_name": "Xu", "given_name": "Yanjun", "orcid": "0000-0003-2443-3698", "clpid": "Xu-Yanjun" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "F\u00fcrst", "given_name": "Felix", "orcid": "0000-0003-0388-0560", "clpid": "F\u00fcrst-F" }, { "family_name": "Harrison", "given_name": "Fiona A.", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" }, { "family_name": "Walton", "given_name": "Dominic J.", "orcid": "0000-0001-5819-3552", "clpid": "Walton-D-J" }, { "family_name": "Tomsick", "given_name": "John A.", "orcid": "0000-0001-5506-9855", "clpid": "Tomsick-J-A" }, { "family_name": "Bachetti", "given_name": "Matteo", "orcid": "0000-0002-4576-9337", "clpid": "Bachetti-M" }, { "family_name": "King", "given_name": "Ashley L.", "clpid": "King-A-L" }, { "family_name": "Madsen", "given_name": "Kristin K.", "orcid": "0000-0003-1252-4891", "clpid": "Madsen-K-K" }, { "family_name": "Miller", "given_name": "Jon M.", "clpid": "Miller-J-M" }, { "family_name": "Grinberg", "given_name": "Victoria", "orcid": "0000-0003-2538-0188", "clpid": "Grinberg-V" } ], "abstract": "We present a spectral and timing study of the NuSTAR and Swift observations of the black hole candidate IGR J17091\u20133624 in the hard state during its outburst in 2016. Disk reflection is detected in each of the NuSTAR spectra taken in three epochs. Fitting with relativistic reflection models reveals that the accretion disk is truncated during all epochs with R_(in) > 10 r_g, with the data favoring a low disk inclination of ~30\u00b0\u201340\u00b0. The steepening of the continuum spectra between epochs is accompanied by a decrease in the high energy cutoff: the electron temperature kT_e drops from ~64 to ~26 keV, changing systematically with the source flux. We detect type-C QPOs in the power spectra with frequency varying between 0.131 and 0.327 Hz. In addition, a secondary peak is found in the power spectra centered at about 2.3 times the QPO frequency during all three epochs. The nature of this secondary frequency is uncertain; however, a non-harmonic origin is favored. We investigate the evolution of the timing and spectral properties during the rising phase of the outburst and discuss their physical implications.", "doi": "10.3847/1538-4357/aa9ab4", "issn": "1538-4357", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2017-12-20", "series_number": "2", "volume": "851", "issue": "2", "pages": "Art. No. 103" }, { "id": "authors:mjxc6-8v705", "collection": "authors", "collection_id": "mjxc6-8v705", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20171212-111502775", "type": "article", "title": "Testing the Performance and Accuracy of the RELXILL Model for the Relativistic X-Ray Reflection from Accretion Disks", "author": [ { "family_name": "Choudhury", "given_name": "Kishalay", "clpid": "Choudhury-K" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Steiner", "given_name": "James F.", "orcid": "0000-0002-5872-6061", "clpid": "Steiner-J-F" }, { "family_name": "Bambi", "given_name": "Cosimo", "orcid": "0000-0002-3180-9502", "clpid": "Bambi-C" } ], "abstract": "The reflection spectroscopic model RELXILL is commonly implemented in studying relativistic X-ray reflection from accretion disks around black holes. We present a systematic study of the model's capability to constrain the dimensionless spin and ionization parameters from ~6000 Nuclear Spectroscopic Telescope Array (NuSTAR) simulations of a bright X-ray source employing the lamp-post geometry. We employ high-count spectra to show the limitations in the model without being confused with limitations in signal-to-noise. We find that both parameters are well-recovered at 90% confidence with improving constraints at higher reflection fraction, high spin, and low source height. We test spectra across a broad range\u2014first at 10^6\u201310^7 and then ~10^5 total source counts across the effective 3\u201379 keV band of NuSTAR, and discover a strong dependence of the results on how fits are performed around the starting parameters, owing to the complexity of the model itself. A blind fit chosen over an approach that carries some estimates of the actual parameter values can lead to significantly worse recovery of model parameters. We further stress the importance to span the space of nonlinear-behaving parameters like log \u03be carefully and thoroughly for the model to avoid misleading results. In light of selecting fitting procedures, we recall the necessity to pay attention to the choice of data binning and fit statistics used to test the goodness of fit by demonstrating the effect on the photon index \u0393. We re-emphasize and implore the need to account for the detector resolution while binning X-ray data and using Poisson fit statistics instead while analyzing Poissonian data.", "doi": "10.3847/1538-4357/aa9925", "issn": "1538-4357", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2017-12-10", "series_number": "1", "volume": "851", "issue": "1", "pages": "Art. No. 57" }, { "id": "authors:s6mfw-0fg09", "collection": "authors", "collection_id": "s6mfw-0fg09", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170901-090512733", "type": "article", "title": "A Suzaku, NuSTAR, and XMM-Newton view on variable absorption and relativistic reflection in NGC 4151", "author": [ { "family_name": "Beuchert", "given_name": "T.", "clpid": "Beuchert-T" }, { "family_name": "Markowitz", "given_name": "A. G.", "clpid": "Markowitz-A-G" }, { "family_name": "Dauser", "given_name": "T.", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-T" }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Keck", "given_name": "M. L.", "clpid": "Keck-M-L" }, { "family_name": "Wilms", "given_name": "J.", "orcid": "0000-0003-2065-5410", "clpid": "Wilms-J" }, { "family_name": "Kadler", "given_name": "M.", "clpid": "Kadler-M" }, { "family_name": "Brenneman", "given_name": "L. W.", "clpid": "Brenneman-L-W" }, { "family_name": "Zdziarski", "given_name": "A. A.", "clpid": "Zdziarski-A-A" } ], "abstract": "We disentangle X-ray disk reflection from complex line-of-sight absorption in the nearby Seyfert NGC 4151, using a suite of Suzaku, NuSTAR, and XMM-Newton observations. Extending upon earlier published work, we pursue a physically motivated model using the latest angle-resolved version of the lamp-post geometry reflection model relxillCp_lp together with a Comptonization continuum. We use the long-look simultaneous Suzaku/NuSTAR observation to develop a baseline model wherein we model reflected emission as a combination of lamp-post components at the heights of 1.2 and 15.0 gravitational radii. We argue for a vertically extended corona as opposed to two compact and distinct primary sources. We find two neutral absorbers (one full-covering and one partial-covering), an ionized absorber (log\u2009\u03be = 2.8), and a highly-ionized ultra-fast outflow, which have all been reported previously. All analyzed spectra are well described by this baseline model. The bulk of the spectral variability between ~1\u2009keV and ~6\u2009keV can be accounted for by changes in the column density of both neutral absorbers, which appear to be degenerate and inversely correlated with the variable hard continuum component flux. We track variability in absorption on both short (2\u2009d) and long (~1\u2009yr) timescales; the observed evolution is either consistent with changes in the absorber structure (clumpy absorber at distances ranging from the broad line region to the inner torus or a dusty radiatively driven wind) or a geometrically stable neutral absorber that becomes increasingly ionized at a rising flux level. The soft X-rays below 1\u2009keV are dominated by photoionized emission from extended gas that may act as a warm mirror for the nuclear radiation.", "doi": "10.1051/0004-6361/201630293", "issn": "0004-6361", "publisher": "EDP Sciences", "publication": "Astronomy and Astrophysics", "publication_date": "2017-07", "volume": "603", "pages": "Art. No. A50" }, { "id": "authors:r2r9q-myg16", "collection": "authors", "collection_id": "r2r9q-myg16", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170331-101614336", "type": "article", "title": "The high-Eddington NLS1 Ark 564 has the coolest corona", "author": [ { "family_name": "Kara", "given_name": "E.", "orcid": "0000-0003-0172-0854", "clpid": "Kara-E" }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Lohfink", "given_name": "A.", "clpid": "Lohfink-A" }, { "family_name": "Fabian", "given_name": "A. C.", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-A-C" }, { "family_name": "Reynolds", "given_name": "C. S.", "clpid": "Reynolds-C-S" }, { "family_name": "Tombesi", "given_name": "F.", "orcid": "0000-0002-6562-8654", "clpid": "Tombesi-F" }, { "family_name": "Wilkins", "given_name": "D. R.", "clpid": "Wilkins-D-R" } ], "abstract": "Ark 564 is an archetypal Narrow line Seyfert 1 that has been well observed in\nsoft X-rays from 0.3-10 keV, revealing a steep spectrum, strong soft excess,\niron K emission line and dramatic variability on the order of hours. Because of\nits very steep spectrum, observations of the source above 10 keV have been\nsparse. We report here on the first NuSTAR observation of Ark 564. The source\nwas observed for 200 ks with NuSTAR, 50 ks of which were concurrent with Suzaku\nobservations. NuSTAR and Suzaku observed a dramatic flare, in which the hard\nemission is clearly delayed with respect to the soft emission, consistent with\nprevious detections of a low-frequency hard lag found in XMM-Newton data. The\nNuSTAR spectrum is well described by a low-temperature Comptonisation continuum\n(with an electron temperature of 15 +/- 2 keV), which irradiates a highly\nionised disc. No further relativistic broadening or ionized absorption is\nrequired. These spectral results show that Ark 564 has one of the lowest\ntemperature coronae observed by NuSTAR to date. We discuss possible reasons for\nlow-temperature coronae in high-Eddington sources.", "doi": "10.1093/mnras/stx792", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2017-07", "series_number": "3", "volume": "468", "issue": "3", "pages": "3489-3498" }, { "id": "authors:djfv9-a3225", "collection": "authors", "collection_id": "djfv9-a3225", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20181002-104710332", "type": "article", "title": "Testing the Kerr Black Hole Hypothesis Using X-Ray Reflection Spectroscopy", "author": [ { "family_name": "Bambi", "given_name": "Cosimo", "orcid": "0000-0002-3180-9502", "clpid": "Bambi-C" }, { "family_name": "C\u00e1rdenas-Avenda\u00f1o", "given_name": "Alejandro", "clpid": "C\u00e1rdenas-Avenda\u00f1o-A" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-T" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Nampalliwar", "given_name": "Sourabh", "clpid": "Nampalliwar-S" } ], "abstract": "We present the first X-ray reflection model for testing the assumption that the metric of astrophysical black holes is described by the Kerr solution. We employ the formalism of the transfer function proposed by Cunningham. The calculations of the reflection spectrum of a thin accretion disk are split into two parts: the calculation of the transfer function and the calculation of the local spectrum at any emission point in the disk. The transfer function only depends on the background metric and takes into account all the relativistic effects (gravitational redshift, Doppler boosting, and light bending). Our code computes the transfer function for a spacetime described by the Johannsen metric and can easily be extended to any stationary, axisymmetric, and asymptotically flat spacetime. Transfer functions and single line shapes in the Kerr metric are compared to those calculated from existing codes to check that we reach the necessary accuracy. We also simulate some observations with NuSTAR and LAD/eXTP and fit the data with our new model to show the potential capabilities of current and future observations to constrain possible deviations from the Kerr metric.", "doi": "10.3847/1538-4357/aa74c0", "issn": "1538-4357", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2017-06-20", "series_number": "2", "volume": "842", "issue": "2", "pages": "Art. No. 76" }, { "id": "authors:nqv24-2sh58", "collection": "authors", "collection_id": "nqv24-2sh58", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170531-110427362", "type": "article", "title": "The X-Ray Reflection Spectrum of the Radio-loud Quasar 4C 74.26", "author": [ { "family_name": "Lohfink", "given_name": "Anne M.", "clpid": "Lohfink-A-M" }, { "family_name": "Fabian", "given_name": "Andrew C.", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-A-C" }, { "family_name": "Ballantyne", "given_name": "David R.", "orcid": "0000-0001-8128-6976", "clpid": "Ballantyne-D-R" }, { "family_name": "Boggs", "given_name": "S. E.", "orcid": "0000-0001-9567-4224", "clpid": "Boggs-S-E" }, { "family_name": "Boorman", "given_name": "Peter", "orcid": "0000-0001-9379-4716", "clpid": "Boorman-P-G" }, { "family_name": "Christensen", "given_name": "F. E.", "orcid": "0000-0001-5679-1946", "clpid": "Christensen-F-E" }, { "family_name": "Craig", "given_name": "W. W.", "clpid": "Craig-W-W" }, { "family_name": "Farrah", "given_name": "Duncan", "orcid": "0000-0003-1748-2010", "clpid": "Farrah-D" }, { "family_name": "Garc\u00eda", "given_name": "Javier", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Hailey", "given_name": "C. J.", "clpid": "Hailey-C-J" }, { "family_name": "Harrison", "given_name": "F. A.", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" }, { "family_name": "Ricci", "given_name": "Claudio", "orcid": "0000-0001-5231-2645", "clpid": "Ricci-C" }, { "family_name": "Stern", "given_name": "Daniel", "orcid": "0000-0003-2686-9241", "clpid": "Stern-D" }, { "family_name": "Zhang", "given_name": "W. W.", "orcid": "0000-0002-1426-9698", "clpid": "Zhang-W-W" } ], "abstract": "The relativistic jets created by some active galactic nuclei are important agents of AGN feedback. In spite of this, our understanding of what produces these jets is still incomplete. X-ray observations, which can probe the processes operating in the central regions in the immediate vicinity of the supermassive black hole, the presumed jet launching point, are potentially particularly valuable in illuminating the jet formation process. Here, we present the hard X-ray NuSTAR observations of the radio-loud quasar 4C 74.26 in a joint analysis with quasi-simultaneous, soft X-ray Swift observations. Our spectral analysis reveals a high-energy cutoff of 183^(+51)_(-35) keV and confirms the presence of ionized reflection in the source. From the average spectrum we detect that the accretion disk is mildly recessed, with an inner radius of R_(in) = 4\u2013180 R_g. However, no significant evolution of the inner radius is seen during the three months covered by our NuSTAR campaign. This lack of variation could mean that the jet formation in this radio-loud quasar differs from what is observed in broad-line radio galaxies.", "doi": "10.3847/1538-4357/aa6d07", "issn": "1538-4357", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2017-06-01", "series_number": "2", "volume": "841", "issue": "2", "pages": "Art. No. 80" }, { "id": "authors:vgm32-hkv61", "collection": "authors", "collection_id": "vgm32-hkv61", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170213-092026356", "type": "article", "title": "The ultracompact nature of the black hole candidate X-ray binary 47 Tuc X9", "author": [ { "family_name": "Bahramian", "given_name": "Arash", "orcid": "0000-0003-2506-6041", "clpid": "Bahramian-A" }, { "family_name": "Heinke", "given_name": "Craig O.", "orcid": "0000-0003-3944-6109", "clpid": "Heinke-C-O" }, { "family_name": "Tudor", "given_name": "Vlad", "clpid": "Tudor-V" }, { "family_name": "Miller-Jones", "given_name": "James C. A.", "orcid": "0000-0003-3124-2814", "clpid": "Miller-Jones-J-C-A" }, { "family_name": "Bogdanov", "given_name": "Slavko", "orcid": "0000-0002-9870-2742", "clpid": "Bogdanov-S" }, { "family_name": "Maccarone", "given_name": "Thomas J.", "orcid": "0000-0003-0976-4755", "clpid": "Maccarone-T-J" }, { "family_name": "Knigge", "given_name": "Christian", "clpid": "Knigge-C" }, { "family_name": "Sivakoff", "given_name": "Gregory R.", "orcid": "0000-0001-6682-916X", "clpid": "Sivakoff-G-R" }, { "family_name": "Chomiuk", "given_name": "Laura", "orcid": "0000-0002-8400-3705", "clpid": "Chomiuk-L" }, { "family_name": "Strader", "given_name": "Jay", "orcid": "0000-0002-1468-9668", "clpid": "Strader-J" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Kallman", "given_name": "Timothy R.", "orcid": "0000-0002-5779-6906", "clpid": "Kallman-Timothy-R" } ], "abstract": "47 Tuc X9 is a low-mass X-ray binary (LMXB) in the globular cluster 47 Tucanae, and was previously thought to be a cataclysmic variable. However, Miller-Jones et al. recently identified a radio counterpart to X9 (inferring a radio/X-ray luminosity ratio consistent with black hole LMXBs), and suggested that the donor star might be a white dwarf. We report simultaneous observations of X9 performed by Chandra, NuSTAR and Australia Telescope Compact Array. We find a clear 28.18 \u00b1 0.02-min periodic modulation in the Chandra data, which we identify as the orbital period, confirming this system as an ultracompact X-ray binary. Our X-ray spectral fitting provides evidence for photoionized gas having a high oxygen abundance in this system, which indicates a C/O white dwarf donor. We also identify reflection features in the hard X-ray spectrum, making X9 the faintest LMXB to show X-ray reflection. We detect an \u223c6.8-d modulation in the X-ray brightness by a factor of 10, in archival Chandra, Swiftand ROSAT data. The simultaneous radio/X-ray flux ratio is consistent with either a black hole primary or a neutron star primary, if the neutron star is a transitional millisecond pulsar. Considering the measured orbital period (with other evidence of a white dwarf donor), and the lack of transitional millisecond pulsar features in the X-ray light curve, we suggest that this could be the first ultracompact black hole X-ray binary identified in our Galaxy.", "doi": "10.1093/mnras/stx166", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2017-05-21", "series_number": "2", "volume": "467", "issue": "2", "pages": "2199-2216" }, { "id": "authors:rcvsm-5xr29", "collection": "authors", "collection_id": "rcvsm-5xr29", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161117-111407065", "type": "article", "title": "Living on a Flare: Relativistic Reflection in V404 Cyg Observed by NuSTAR During its Summer 2015 Outburst", "author": [ { "family_name": "Walton", "given_name": "D. J.", "orcid": "0000-0001-5819-3552", "clpid": "Walton-D-J" }, { "family_name": "Mooley", "given_name": "K.", "orcid": "0000-0002-2557-5180", "clpid": "Mooley-Kunal-Prakash" }, { "family_name": "King", "given_name": "A", "clpid": "King-A-L" }, { "family_name": "Tomsick", "given_name": "J. A.", "orcid": "0000-0001-5506-9855", "clpid": "Tomsick-J-A" }, { "family_name": "Miller", "given_name": "J. M.", "clpid": "Miller-J-M" }, { "family_name": "Dauser", "given_name": "T.", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-T" }, { "family_name": "Garc\u00eda", "given_name": "J.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Bachetti", "given_name": "M.", "orcid": "0000-0002-4576-9337", "clpid": "Bachetti-M" }, { "family_name": "Brightman", "given_name": "M.", "orcid": "0000-0002-8147-2602", "clpid": "Brightman-M" }, { "family_name": "Fabian", "given_name": "A. C.", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-A-C" }, { "family_name": "Forster", "given_name": "K.", "orcid": "0000-0001-5800-5531", "clpid": "Forster-K" }, { "family_name": "F\u00fcrst", "given_name": "F.", "orcid": "0000-0003-0388-0560", "clpid": "F\u00fcrst-F" }, { "family_name": "Gandhi", "given_name": "P.", "orcid": "0000-0003-3105-2615", "clpid": "Gandhi-Poshak" }, { "family_name": "Grefenstette", "given_name": "B. W.", "orcid": "0000-0002-1984-2932", "clpid": "Grefenstette-B-W" }, { "family_name": "Harrison", "given_name": "F. A.", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" }, { "family_name": "Madsen", "given_name": "K. K.", "orcid": "0000-0003-1252-4891", "clpid": "Madsen-K-K" }, { "family_name": "Meier", "given_name": "D. L.", "clpid": "Meier-D-L" }, { "family_name": "Middleton", "given_name": "M. J.", "orcid": "0000-0002-8183-2970", "clpid": "Middleton-M-J" }, { "family_name": "Natalucci", "given_name": "L.", "orcid": "0000-0002-6601-9543", "clpid": "Natalucci-L" }, { "family_name": "Rahoui", "given_name": "F.", "orcid": "0000-0001-7655-4120", "clpid": "Rahoui-F" }, { "family_name": "Rana", "given_name": "V.", "orcid": "0000-0003-1703-8796", "clpid": "Rana-V-R" }, { "family_name": "Stern", "given_name": "D.", "orcid": "0000-0003-2686-9241", "clpid": "Stern-D" } ], "abstract": "We present first results from a series of NuSTAR observations of the black hole X-ray binary V404 Cyg obtained during its summer 2015 outburst, primarily focusing on observations during the height of this outburst activity. The NuSTAR data show extreme variability in both the flux and spectral properties of the source. This is partly driven by strong and variable line-of-sight absorption, similar to previous outbursts. The latter stages of this observation are dominated by strong flares, reaching luminosities close to Eddington. During these flares, the central source appears to be relatively unobscured and the data show clear evidence for a strong contribution from relativistic reflection, providing a means to probe the geometry of the innermost accretion flow. Based on the flare properties, analogies with other Galactic black hole binaries, and also the simultaneous onset of radio activity, we argue that this intense X-ray flaring is related to transient jet activity during which the ejected plasma is the primary source of illumination for the accretion disk. If this is the case, then our reflection modeling implies that these jets are launched in close proximity to the black hole (as close as a few gravitational radii), consistent with expectations for jet launching models that tap either the spin of the central black hole, or the very innermost accretion disk. Our analysis also allows us to place the first constraints on the black hole spin for this source, which we find to be a* > 0.92 (99% statistical uncertainty, based on an idealized lamp-post geometry).", "doi": "10.3847/1538-4357/aa67e8", "issn": "1538-4357", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2017-04-20", "series_number": "2", "volume": "839", "issue": "2", "pages": "Art. No. 110" }, { "id": "authors:t0j90-vg715", "collection": "authors", "collection_id": "t0j90-vg715", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170301-125605305", "type": "article", "title": "The response of relativistic outflowing gas to the inner accretion disk of a black hole", "author": [ { "family_name": "Parker", "given_name": "Michael L.", "orcid": "0000-0002-8466-7317", "clpid": "Parker-M-L" }, { "family_name": "Pinto", "given_name": "Ciro", "orcid": "0000-0003-2532-7379", "clpid": "Pinto-C" }, { "family_name": "Fabian", "given_name": "Andrew C.", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-A-C" }, { "family_name": "Lohfink", "given_name": "Anne M.", "clpid": "Lohfink-A-M" }, { "family_name": "Buisson", "given_name": "Douglas J. K.", "clpid": "Buisson-D-J-K" }, { "family_name": "Alston", "given_name": "William N.", "orcid": "0000-0003-2658-6559", "clpid": "Alston-W-N" }, { "family_name": "Kara", "given_name": "Erin", "orcid": "0000-0003-0172-0854", "clpid": "Kara-E" }, { "family_name": "Cackett", "given_name": "Edward M.", "orcid": "0000-0002-8294-9281", "clpid": "Cackett-E-M" }, { "family_name": "Chiang", "given_name": "Chia-Ying", "orcid": "0000-0002-9630-4003", "clpid": "Chiang-Chia-Ying" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-T" }, { "family_name": "De Marco", "given_name": "Barbara", "clpid": "De-Marco-B" }, { "family_name": "Gallo", "given_name": "Luigi C.", "clpid": "Gallo-L-C" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Harrison", "given_name": "Fiona A.", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" }, { "family_name": "King", "given_name": "Ashley L.", "clpid": "King-A-L" }, { "family_name": "Middleton", "given_name": "Matthew J.", "orcid": "0000-0002-8183-2970", "clpid": "Middleton-M-J" }, { "family_name": "Miller", "given_name": "Jon M.", "clpid": "Miller-J-M" }, { "family_name": "Miniutti", "given_name": "Giovanni", "clpid": "Miniutti-G" }, { "family_name": "Reynolds", "given_name": "Christopher S.", "clpid": "Reynolds-C-S" }, { "family_name": "Uttley", "given_name": "Phil", "clpid": "Uttley-P" }, { "family_name": "Vasudevan", "given_name": "Ranjan", "clpid": "Vasudevan-R-V" }, { "family_name": "Walton", "given_name": "D. J.", "orcid": "0000-0001-5819-3552", "clpid": "Walton-D-J" }, { "family_name": "Wilkins", "given_name": "Daniel R.", "clpid": "Wilkins-D-R" }, { "family_name": "Zoghbi", "given_name": "Abderahmen", "orcid": "0000-0002-0572-9613", "clpid": "Zoghbi-A" } ], "abstract": "The brightness of an active galactic nucleus is set by the gas falling onto it from the galaxy, and the gas infall rate is regulated by the brightness of the active galactic nucleus; this feedback loop is the process by which supermassive black holes in the centres of galaxies may moderate the growth of their hosts1. Gas outflows (in the form of disk winds) release huge quantities of energy into the interstellar medium2, potentially clearing the surrounding gas. The most extreme (in terms of speed and energy) of these\u2014the ultrafast outflows\u2014are the subset of X-ray-detected outflows with velocities higher than 10,000 kilometres per second, believed to originate in relativistic (that is, near the speed of light) disk winds a few hundred gravitational radii from the black hole3. The absorption features produced by these outflows are variable4, but no clear link has been found between the behaviour of the X-ray continuum and the velocity or optical depth of the outflows, owing to the long timescales of quasar variability. Here we report the observation of multiple absorption lines from an extreme ultrafast gas flow in the X-ray spectrum of the active galactic nucleus IRAS 13224\u22123809, at 0.236\u2009\u00b1\u20090.006 times the speed of light (71,000 kilometres per second), where the absorption is strongly anti-correlated with the emission of X-rays from the inner regions of the accretion disk. If the gas flow is identified as a genuine outflow then it is in the fastest five per cent of such winds, and its variability is hundreds of times faster than in other variable winds, allowing us to observe in hours what would take months in a quasar. We find X-ray spectral signatures of the wind simultaneously in both low- and high-energy detectors, suggesting a single ionized outflow, linking the low- and high-energy absorption lines. That this disk wind is responding to the emission from the inner accretion disk demonstrates a connection between accretion processes occurring on very different scales: the X-ray emission from within a few gravitational radii of the black hole ionizing the disk wind hundreds of gravitational radii further away as the X-ray flux rises.", "doi": "10.1038/nature21385", "issn": "0028-0836", "publisher": "Nature Publishing Group", "publication": "Nature", "publication_date": "2017-03-01", "series_number": "7643", "volume": "543", "issue": "7643", "pages": "83-86" }, { "id": "authors:4s7hf-ahr21", "collection": "authors", "collection_id": "4s7hf-ahr21", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170228-110354967", "type": "article", "title": "Evidence for Relativistic Disk Reflection in the Seyfert 1h Galaxy/ULIRG IRAS 05189\u20132524 Observed by NuSTAR and XMM-Newton", "author": [ { "family_name": "Xu", "given_name": "Yanjun", "orcid": "0000-0003-2443-3698", "clpid": "Xu-Yanjun" }, { "family_name": "Balokovi\u0107", "given_name": "Mislav", "orcid": "0000-0003-0476-6647", "clpid": "Balokovi\u0107-M" }, { "family_name": "Walton", "given_name": "Dominic J.", "orcid": "0000-0001-5819-3552", "clpid": "Walton-D-J" }, { "family_name": "Harrison", "given_name": "Fiona A.", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Koss", "given_name": "Michael J.", "orcid": "0000-0002-7998-9581", "clpid": "Koss-M-J" } ], "abstract": "We present a spectral analysis of the NuSTAR and XMM-Newton observations of the Seyfert 1h galaxy/ULIRG IRAS 05189\u20132524 taken in 2013. We find evidence for relativistic disk reflection in the broadband X-ray spectrum: a highly asymmetric broad Fe K\u03b1 emission line extending down to 3 keV and a Compton scattering component above 10 keV. Physical modeling with a self-consistent disk reflection model suggests that the accretion disk is viewed at an intermediate angle with a supersolar iron abundance, and a mild constraint can be put on the high-energy cutoff of the power-law continuum. We test the disk reflection modeling under different absorption scenarios. A rapid black hole spin is favored; however, we cannot place a model-independent tight constraint on the value. The high reflection fraction (R_(ref) \u2243 2.0\u20133.2) suggests that the coronal illuminating source is compact and close to the black hole (lying within 8.7 R_g above the central black hole), where light-bending effects are important.", "doi": "10.3847/1538-4357/aa5df4", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2017-03-01", "series_number": "1", "volume": "837", "issue": "1", "pages": "Art. No. 21" }, { "id": "authors:632g1-ha040", "collection": "authors", "collection_id": "632g1-ha040", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170206-142411468", "type": "article", "title": "A Long Look at MCG-5-23-16 with NuSTAR. I. Relativistic Reflection and Coronal Properties", "author": [ { "family_name": "Zoghbi", "given_name": "Abderahmen", "orcid": "0000-0002-0572-9613", "clpid": "Zoghbi-A" }, { "family_name": "Matt", "given_name": "G.", "orcid": "0000-0002-2152-0916", "clpid": "Matt-G" }, { "family_name": "Miller", "given_name": "J. M.", "clpid": "Miller-J-M" }, { "family_name": "Lohfink", "given_name": "A. M.", "clpid": "Lohfink-A-M" }, { "family_name": "Walton", "given_name": "D. J.", "orcid": "0000-0001-5819-3552", "clpid": "Walton-D-J" }, { "family_name": "Ballantyne", "given_name": "D. R.", "orcid": "0000-0001-8128-6976", "clpid": "Ballantyne-D-R" }, { "family_name": "Garc\u00eda", "given_name": "J. A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Stern", "given_name": "D.", "orcid": "0000-0003-2686-9241", "clpid": "Stern-D" }, { "family_name": "Koss", "given_name": "M. J.", "orcid": "0000-0002-7998-9581", "clpid": "Koss-M-J" }, { "family_name": "Farrah", "given_name": "D.", "orcid": "0000-0003-1748-2010", "clpid": "Farrah-D" }, { "family_name": "Harrison", "given_name": "F. A.", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" }, { "family_name": "Boggs", "given_name": "S. E.", "orcid": "0000-0001-9567-4224", "clpid": "Boggs-S-E" }, { "family_name": "Christensen", "given_name": "F. E.", "orcid": "0000-0001-5679-1946", "clpid": "Christensen-F-E" }, { "family_name": "Craig", "given_name": "W.", "clpid": "Craig-W-W" }, { "family_name": "Hailey", "given_name": "C. J.", "clpid": "Hailey-C-J" }, { "family_name": "Zhang", "given_name": "W. W.", "orcid": "0000-0002-1426-9698", "clpid": "Zhang-W-W" } ], "abstract": "MCG-5-23-16 was targeted in early 2015 with a half mega-second observing campaign using NuSTAR. Here we present the spectral analysis of these data sets along with an earlier observation and study the relativistic reflection and the primary coronal source. The data show strong reflection features in the form of both narrow and broad iron lines plus a Compton reflection hump. A cutoff energy is significantly detected in all exposures. The shape of the reflection spectrum does not change in the two years spanned by the observations, suggesting a stable geometry. A strong positive correlation is found between the cutoff energy and both the hard X-ray flux and spectral index. The measurements imply that the coronal plasma is not at the runaway electron\u2013positron pair limit, and instead contains mostly electrons. The observed variability in the coronal properties is driven by a variable optical depth. A constant heating-to-cooling ratio is measured, implying that there is a feedback mechanism in which a significant fraction of the photons cooling the corona are due to reprocessed hard X-rays.", "doi": "10.3847/1538-4357/aa582c", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2017-02-10", "series_number": "1", "volume": "836", "issue": "1", "pages": "Art. No. 2" }, { "id": "authors:ndfnq-9et03", "collection": "authors", "collection_id": "ndfnq-9et03", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170213-161331493", "type": "article", "title": "Self-consistent Black Hole Accretion Spectral Models and the Forgotten Role of Coronal Comptonization of Reflection Emission", "author": [ { "family_name": "Steiner", "given_name": "James F.", "orcid": "0000-0002-5872-6061", "clpid": "Steiner-J-F" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Eikmann", "given_name": "Wiebke", "clpid": "Eikmann-W" }, { "family_name": "McClintock", "given_name": "Jeffrey E.", "clpid": "McClintock-J-E" }, { "family_name": "Brenneman", "given_name": "Laura W.", "clpid": "Brenneman-L-W" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-T" }, { "family_name": "Fabian", "given_name": "Andrew C.", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-A-C" } ], "abstract": "Continuum and reflection spectral models have each been widely employed in measuring the spins of accreting black holes. However, the two approaches have not been implemented together in a photon-conserving, self-consistent framework. We develop such a framework using the black hole X-ray binary GX 339\u20134 as a touchstone source, and we demonstrate three important ramifications. (1) Compton scattering of reflection emission in the corona is routinely ignored, but is an essential consideration given that reflection is linked to the regimes with strongest Comptonization. Properly accounting for this causes the inferred reflection fraction to increase substantially, especially for the hard state. Another important impact of the Comptonization of reflection emission by the corona is the downscattered tail. Downscattering has the potential to mimic the relativistically broadened red wing of the Fe line associated with a spinning black hole. (2) Recent evidence for a reflection component with a harder spectral index than the power-law continuum is naturally explained as Compton-scattered reflection emission. (3) Photon conservation provides an important constraint on the hard state's accretion rate. For bright hard states, we show that disk truncation to large scales R \u00bb R_(ISCO) is unlikely as this would require accretion rates far in excess of the observed \u1e40 of the brightest soft states. Our principal conclusion is that when modeling relativistically broadened reflection, spectral models should allow for coronal Compton scattering of the reflection features, and when possible, take advantage of the additional constraining power from linking to the thermal disk component.", "doi": "10.3847/1538-4357/836/1/119", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2017-02-10", "series_number": "1", "volume": "836", "issue": "1", "pages": "Art. No. 119" }, { "id": "authors:x2r8h-v5j68", "collection": "authors", "collection_id": "x2r8h-v5j68", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161122-123106476", "type": "article", "title": "GRS 1739-278 Observed at Very Low Luminosity with XMM-Newton and NuSTAR", "author": [ { "family_name": "F\u00fcrst", "given_name": "F.", "orcid": "0000-0003-0388-0560", "clpid": "F\u00fcrst-F" }, { "family_name": "Tomsick", "given_name": "J. A.", "orcid": "0000-0001-5506-9855", "clpid": "Tomsick-J-A" }, { "family_name": "Yamaoka", "given_name": "K.", "clpid": "Yamaoka-Kazutaka" }, { "family_name": "Dauser", "given_name": "T.", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-T" }, { "family_name": "Miller", "given_name": "J. M.", "clpid": "Miller-J-M" }, { "family_name": "Clavel", "given_name": "M.", "orcid": "0000-0003-0724-2742", "clpid": "Clavel-M" }, { "family_name": "Corbel", "given_name": "S.", "clpid": "Corbel-S" }, { "family_name": "Fabian", "given_name": "A. C.", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-A-C" }, { "family_name": "Garc\u00eda", "given_name": "J.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Harrison", "given_name": "F. A.", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" }, { "family_name": "Loh", "given_name": "A.", "clpid": "Loh-Alan" }, { "family_name": "Kaaret", "given_name": "P.", "orcid": "0000-0002-3638-0637", "clpid": "Kaaret-P" }, { "family_name": "Kalemci", "given_name": "E.", "clpid": "Kalemci-E" }, { "family_name": "Migliari", "given_name": "S.", "clpid": "Migliari-S" }, { "family_name": "Miller-Jones", "given_name": "J. C. A.", "orcid": "0000-0003-3124-2814", "clpid": "Miller-Jones-J-C-A" }, { "family_name": "Pottschmidt", "given_name": "K.", "orcid": "0000-0002-4656-6881", "clpid": "Pottschmidt-K" }, { "family_name": "Rahoui", "given_name": "F.", "orcid": "0000-0001-7655-4120", "clpid": "Rahoui-F" }, { "family_name": "Rodriguez", "given_name": "J.", "clpid": "Rodriguez-J" }, { "family_name": "Stern", "given_name": "D.", "orcid": "0000-0003-2686-9241", "clpid": "Stern-D" }, { "family_name": "Stuhlinger", "given_name": "M.", "clpid": "Stuhlinger-M" }, { "family_name": "Walton", "given_name": "D. J.", "orcid": "0000-0001-5819-3552", "clpid": "Walton-D-J" }, { "family_name": "Wilms", "given_name": "J.", "orcid": "0000-0003-2065-5410", "clpid": "Wilms-J" } ], "abstract": "We present a detailed spectral analysis of XMM-Newton and NuSTAR observations of the accreting transient black hole GRS 1739\u2212278 during a very faint low hard state at ~0.02% of the Eddington luminosity (for a distance of 8.5 kpc and a mass of 10 M\u2299). The broadband X-ray spectrum between 0.5 and 60 keV can be well-described by a power-law continuum with an exponential cutoff. The continuum is unusually hard for such a low luminosity, with a photon index of \u0393 = 1.39 \u00b1 0.04. We find evidence for an additional reflection component from an optically thick accretion disk at the 98% likelihood level. The reflection fraction is low, with R_(refl) = 0.043^(+0.033)_(-0.023). In combination with measurements of the spin and inclination parameters made with NuSTAR during a brighter hard state by Miller et al., we seek to constrain the accretion disk geometry. Depending on the assumed emissivity profile of the accretion disk, we find a truncation radius of 15\u201335 R_g(5\u201312 R_(ISCO)) at the 90% confidence limit. These values depend strongly on the assumptions and we discuss possible systematic uncertainties.", "doi": "10.3847/0004-637X/832/2/115", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2016-12-01", "series_number": "2", "volume": "832", "issue": "2", "pages": "Art. No. 115" }, { "id": "authors:75pvr-vfv22", "collection": "authors", "collection_id": "75pvr-vfv22", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160715-103832095", "type": "article", "title": "Normalizing a relativistic model of X-ray reflection: \n Definition of the reflection fraction and its implementation in relxill", "author": [ { "family_name": "Dauser", "given_name": "T.", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-T" }, { "family_name": "Garc\u00eda", "given_name": "J.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Walton", "given_name": "D. J.", "orcid": "0000-0001-5819-3552", "clpid": "Walton-D-J" }, { "family_name": "Eikmann", "given_name": "W.", "clpid": "Eikmann-W" }, { "family_name": "Kallman", "given_name": "T.", "orcid": "0000-0002-5779-6906", "clpid": "Kallman-Timothy-R" }, { "family_name": "McClintock", "given_name": "J.", "clpid": "McClintock-J-E" }, { "family_name": "Wilms", "given_name": "J.", "orcid": "0000-0003-2065-5410", "clpid": "Wilms-J" } ], "abstract": "Aims. The only relativistic reflection model that implements a parameter relating the intensity incident on an accretion disk to the observed intensity is relxill. The parameter used in earlier versions of this model, referred to as the reflection strength, is unsatisfactory; it has been superseded by a parameter that provides insight into the accretion geometry, namely the reflection fraction. The reflection fraction is defined as the ratio of the coronal intensity illuminating the disk to the coronal intensity that reaches the observer.\n\nMethods. The relxill model combines a general relativistic ray-tracing code and a photoionization code to compute the component of radiation reflected from an accretion that is illuminated by an external source. The reflection fraction is a particularly important parameter for relativistic models with well-defined geometry, such as the lamp post model, which is a focus of this paper.\n\nResults. Relativistic spectra are compared for three inclinations and for four values of the key parameter of the lamp post model, namely the height above the black hole of the illuminating, on-axis point source. In all cases, the strongest reflection is produced for low source heights and high spin. A low-spin black hole is shown to be incapable of producing enhanced relativistic reflection. Results for the relxill model are compared to those obtained with other models and a Monte Carlo simulation.\n\nConclusions. Fitting data by using the relxill model and the recently implemented reflection fraction, the geometry of a system can be constrained. The reflection fraction is independent of system parameters such as inclination and black hole spin. The reflection-fraction parameter was implemented with the name refl_frac in all flavours of the relxill model, and the non-relativistic reflection model xillver, in v0.4a (18 January 2016).", "doi": "10.1051/0004-6361/201628135", "issn": "0004-6361", "publisher": "EDP Sciences", "publication": "Astronomy and Astrophysics", "publication_date": "2016-06", "volume": "590", "pages": "Art. No. A76" }, { "id": "authors:jd088-pch67", "collection": "authors", "collection_id": "jd088-pch67", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160527-121830000", "type": "article", "title": "Relativistic reflection: Review and recent developments in modeling", "author": [ { "family_name": "Dauser", "given_name": "T.", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-T" }, { "family_name": "Garc\u00eda", "given_name": "J.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Wilms", "given_name": "J.", "orcid": "0000-0003-2065-5410", "clpid": "Wilms-J" } ], "abstract": "Measuring relativistic reflection is an important tool to study the innermost regions of the an accreting black hole system. In the following we present a brief review on the different aspects contributing to the relativistic reflection. The combined approach is for the first time incorporated in the new \"relxill\" model. The advantages of this more self-consistent approach are briefly summarized. A special focus is put on the new definition of the intrinsic reflection fraction in the lamp post geometry, which allows to draw conclusions about the primary source of radiation in these system. Additionally the influence of the high energy cutoff of the primary source on the reflection spectrum is motivated, revealing the remarkable capabilities of constraining E_cut by measuring relativistic reflection spectra from NuSTAR, preferably with lower energy coverage.", "doi": "10.1002/asna.201612314", "issn": "0004-6337", "publisher": "Wiley", "publication": "Astronomische Nachrichten", "publication_date": "2016-05", "series_number": "4-5", "volume": "337", "issue": "4-5", "pages": "362-367" }, { "id": "authors:pnfy7-cg528", "collection": "authors", "collection_id": "pnfy7-cg528", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160128-120939504", "type": "article", "title": "On the Spin of the Black Hole in IC 10 X-1", "author": [ { "family_name": "Steiner", "given_name": "James F.", "orcid": "0000-0002-5872-6061", "clpid": "Steiner-J-F" }, { "family_name": "Walton", "given_name": "Dominic J.", "orcid": "0000-0001-5819-3552", "clpid": "Walton-D-J" }, { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "McClintock", "given_name": "Jeffrey E.", "clpid": "McClintock-J-E" }, { "family_name": "Laycock", "given_name": "Silas G. T.", "clpid": "Laycock-S-G-T" }, { "family_name": "Middleton", "given_name": "Matthew J.", "orcid": "0000-0002-8183-2970", "clpid": "Middleton-M-J" }, { "family_name": "Barnard", "given_name": "Robin", "clpid": "Barnard-R" }, { "family_name": "Madsen", "given_name": "Kristin K.", "orcid": "0000-0003-1252-4891", "clpid": "Madsen-K-K" } ], "abstract": "The compact X-ray source in the eclipsing X-ray binary IC 10 X\u20131 has reigned for years as ostensibly the most massive stellar-mass black hole, with a mass estimated to be about twice that of its closest rival. However, striking results presented recently by Laycock et al. reveal that the mass estimate, based on emission-line velocities, is unreliable and that the mass of the X-ray source is essentially unconstrained. Using Chandra and NuSTAR data, we rule against a neutron-star model and conclude that IC 10 X\u20131 contains a black hole. The eclipse duration of IC 10 X\u20131 is shorter and its depth shallower at higher energies, an effect consistent with the X-ray emission being obscured during eclipse by a Compton-thick core of a dense wind. The spectrum is strongly disk-dominated, which allows us to constrain the spin of the black hole via X-ray continuum fitting. Three other wind-fed black hole systems are known; the masses and spins of their black holes are high: M ~ 10 - 15M_\u2609 and \u0251_* > 0.8. If the mass of IC 10 X-1's black hole is comparable, then its spin is likewise high.", "doi": "10.3847/0004-637X/817/2/154", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2016-02-01", "series_number": "2", "volume": "817", "issue": "2", "pages": "Art. No. 154" }, { "id": "authors:tn4hr-8q267", "collection": "authors", "collection_id": "tn4hr-8q267", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150824-150947187", "type": "article", "title": "On Estimating the High-Energy Cutoff in the X-Ray Spectra of Black Holes via Reflection Spectroscopy", "author": [ { "family_name": "Garc\u00eda", "given_name": "Javier A.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Dauser", "given_name": "Thomas", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-T" }, { "family_name": "Steiner", "given_name": "James F.", "orcid": "0000-0002-5872-6061", "clpid": "Steiner-J-F" }, { "family_name": "McClintock", "given_name": "Jeffrey E.", "clpid": "McClintock-J-E" }, { "family_name": "Keck", "given_name": "Mason L.", "clpid": "Keck-M-L" }, { "family_name": "Wilms", "given_name": "J\u00f6rn", "orcid": "0000-0003-2065-5410", "clpid": "Wilms-J" } ], "abstract": "The fundamental parameters describing the coronal spectrum of an accreting black hole are the slope \u0393 of the power-law continuum and the energy E_(cut) at which it rolls over. Remarkably, this latter parameter can be accurately measured for values as high as 1 MeV by modeling the spectrum of X-rays reflected from a black hole accretion disk at energies below 100 keV. This is possible because the details in the reflection spectrum, rich in fluorescent lines and other atomic features, are very sensitive to the spectral shape of the hardest coronal radiation illuminating the disk. We show that by fitting simultaneous NuSTAR (3\u201379 keV) and low-energy (e.g., Suzaku) data with the most recent version of our reflection model relxill one can obtain reasonable constraints on E_(cut) at energies from tens of keV up to 1 MeV, for a source as faint as 1 mCrab in a 100 ks observation.", "doi": "10.1088/2041-8205/808/2/L37", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2015-07-27", "series_number": "2", "volume": "808", "issue": "2", "pages": "L37-L42" }, { "id": "authors:rcxed-7b270", "collection": "authors", "collection_id": "rcxed-7b270", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150803-105900589", "type": "article", "title": "NuSTAR and Suzaku X-Ray Spectroscopy of NGC 4151: Evidence for Reflection from the Inner Accretion Disk", "author": [ { "family_name": "Keck", "given_name": "M. L.", "clpid": "Keck-M-L" }, { "family_name": "Brenneman", "given_name": "L. W.", "clpid": "Brenneman-L-W" }, { "family_name": "Ballantyne", "given_name": "D. R.", "orcid": "0000-0001-8128-6976", "clpid": "Ballantyne-D-R" }, { "family_name": "Bauer", "given_name": "F.", "orcid": "0000-0002-8686-8737", "clpid": "Bauer-F-E" }, { "family_name": "Boggs", "given_name": "S. E.", "orcid": "0000-0001-9567-4224", "clpid": "Boggs-S-E" }, { "family_name": "Christensen", "given_name": "F. E.", "orcid": "0000-0001-5679-1946", "clpid": "Christensen-F-E" }, { "family_name": "Craig", "given_name": "W. W.", "clpid": "Craig-W-W" }, { "family_name": "Dauser", "given_name": "T.", "orcid": "0000-0003-4583-9048", "clpid": "Dauser-T" }, { "family_name": "Elvis", "given_name": "M.", "clpid": "Elvis-M" }, { "family_name": "Fabian", "given_name": "A. C.", "orcid": "0000-0002-9378-4072", "clpid": "Fabian-A-C" }, { "family_name": "Fuerst", "given_name": "F.", "orcid": "0000-0003-0388-0560", "clpid": "F\u00fcrst-F" }, { "family_name": "Garc\u00eda", "given_name": "J.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Grefenstette", "given_name": "B. W.", "orcid": "0000-0002-1984-2932", "clpid": "Grefenstette-B-W" }, { "family_name": "Hailey", "given_name": "C. J.", "clpid": "Hailey-C-J" }, { "family_name": "Harrison", "given_name": "F. A.", "orcid": "0000-0002-4226-8959", "clpid": "Harrison-F-A" }, { "family_name": "Madejski", "given_name": "G.", "clpid": "Madejski-G-M" }, { "family_name": "Marinucci", "given_name": "A.", "clpid": "Marinucci-A" }, { "family_name": "Matt", "given_name": "G.", "orcid": "0000-0002-2152-0916", "clpid": "Matt-G" }, { "family_name": "Reynolds", "given_name": "C. S.", "clpid": "Reynolds-C-S" }, { "family_name": "Stern", "given_name": "D.", "orcid": "0000-0003-2686-9241", "clpid": "Stern-D" }, { "family_name": "Walton", "given_name": "D. J.", "orcid": "0000-0001-5819-3552", "clpid": "Walton-D-J" }, { "family_name": "Zoghbi", "given_name": "A.", "orcid": "0000-0002-0572-9613", "clpid": "Zoghbi-A" } ], "abstract": "We present X-ray timing and spectral analyses of simultaneous 150 ks Nuclear Spectroscopic Telescope Array (NuSTAR) and Suzaku X-ray observations of the Seyfert 1.5 galaxy NGC 4151. We disentangle the continuum emission, absorption, and reflection properties of the active galactic nucleus (AGN) by applying inner accretion disk reflection and absorption-dominated models. With a time-averaged spectral analysis, we find strong evidence for relativistic reflection from the inner accretion disk. We find that relativistic emission arises from a highly ionized inner accretion disk with a steep emissivity profile, which suggests an intense, compact illuminating source. We find a preliminary, near-maximal black hole spin_(\u0251 > 0.9) accounting for statistical and systematic modeling errors. We find a relatively moderate reflection fraction with respect to predictions for the lamp post geometry, in which the illuminating corona is modeled as a point source. Through a time-resolved spectral analysis, we find that modest coronal and inner disk reflection (IDR) flux variation drives the spectral variability during the observations. We discuss various physical scenarios for the IDR model and we find that a compact corona is consistent with the observed features.", "doi": "10.1088/0004-637X/806/2/149", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2015-06-20", "series_number": "2", "volume": "806", "issue": "2", "pages": "Art. No. 149" }, { "id": "authors:dh385-5vt67", "collection": "authors", "collection_id": "dh385-5vt67", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20090924-160333378", "type": "article", "title": "Milliarcsecond N-Band Observations of the Nova RS Ophiuchi: First Science with the Keck Interferometer Nuller", "author": [ { "family_name": "Barry", "given_name": "R. K.", "clpid": "Barry-R-K" }, { "family_name": "Danchi", "given_name": "W. C.", "clpid": "Danchi-W-C" }, { "family_name": "Traub", "given_name": "W. A.", "clpid": "Traub-W-A" }, { "family_name": "Sokoloski", "given_name": "J. L.", "clpid": "Sokoloski-J-L" }, { "family_name": "Wisniewski", "given_name": "J. P.", "orcid": "0000-0001-9209-1808", "clpid": "Wisniewski-J-P" }, { "family_name": "Serabyn", "given_name": "E.", "clpid": "Serabyn-E" }, { "family_name": "Kuchner", "given_name": "M. J.", "orcid": "0000-0002-2387-5489", "clpid": "Kuchner-M-J" }, { "family_name": "Akeson", "given_name": "R.", "orcid": "0000-0001-9674-1564", "clpid": "Akeson-R-L" }, { "family_name": "Appleby", "given_name": "E.", "clpid": "Appleby-E" }, { "family_name": "Bell", "given_name": "J.", "clpid": "Bell-J" }, { "family_name": "Booth", "given_name": "A.", "clpid": "Booth-A" }, { "family_name": "Brandenburg", "given_name": "H.", "clpid": "Brandenburg-H" }, { "family_name": "Colavita", "given_name": "M.", "clpid": "Colavita-M-M" }, { "family_name": "Crawford", "given_name": "S.", "clpid": "Crawford-S" }, { "family_name": "Creech-Eakman", "given_name": "M.", "clpid": "Creech-Eakman-M-J" }, { "family_name": "Dahl", "given_name": "W.", "clpid": "Dahl-W" }, { "family_name": "Felizardo", "given_name": "C.", "clpid": "Felizardo-C" }, { "family_name": "Garcia", "given_name": "J.", "orcid": "0000-0003-3828-2448", "clpid": "Garc\u00eda-Javier-A" }, { "family_name": "Gathright", "given_name": "J.", "clpid": "Gathright-J-T" }, { "family_name": "Greenhouse", "given_name": "M. A.", "clpid": "Greenhouse-M-A" }, { "family_name": "Herstein", "given_name": "J.", "clpid": "Herstein-J-S" }, { "family_name": "Hovland", "given_name": "E.", "clpid": "Hovland-E-E" }, { "family_name": "Hrynevych", "given_name": "M.", "clpid": "Hrynevych-M-A" }, { "family_name": "Koresko", "given_name": "C.", "clpid": "Koresko-C-D" }, { "family_name": "Ligon", "given_name": "R.", "clpid": "Ligon-E-R" }, { "family_name": "Mennesson", "given_name": "B.", "orcid": "0000-0003-4205-4800", "clpid": "Mennesson-B" }, { "family_name": "Millan-Gabet", "given_name": "R.", "orcid": "0000-0003-0447-5866", "clpid": "Millan-Gabet-R" }, { "family_name": "Morrison", "given_name": "D.", "clpid": "Morrison-D" }, { "family_name": "Palmer", "given_name": "D.", "clpid": "Palmer-D-L" }, { "family_name": "Panteleeva", "given_name": "T.", "clpid": "Panteleeva-T" }, { "family_name": "Ragland", "given_name": "S.", "clpid": "Ragland-S" }, { "family_name": "Shao", "given_name": "M.", "clpid": "Shao-Michael" }, { "family_name": "Smythe", "given_name": "R.", "clpid": "Smythe-R-F" }, { "family_name": "Summers", "given_name": "K.", "clpid": "Summers-K-R" }, { "family_name": "Swain", "given_name": "M.", "clpid": "Swain-M" }, { "family_name": "Tsubota", "given_name": "K.", "clpid": "Tsubota-Kevin" }, { "family_name": "Tyau", "given_name": "C.", "clpid": "Tyau-C" }, { "family_name": "Wetherell", "given_name": "E.", "clpid": "Wetherell-E" }, { "family_name": "Wizinowich", "given_name": "P.", "orcid": "0000-0002-1646-442X", "clpid": "Wizinowich-P-L" }, { "family_name": "Woillez", "given_name": "J.", "clpid": "Woillez-J-M" }, { "family_name": "Vasisht", "given_name": "G.", "orcid": "0000-0002-1871-6264", "clpid": "Vasisht-G" } ], "abstract": "We report observations of the nova RS Ophiuchi (RS Oph) using the Keck Interferometer Nuller (KIN), approximately 3.8 days following the most recent outburst that occurred on 2006 February 12. These observations represent the first scientific results from the KIN, which operates in N band from 8 to 12.5 \u03bcm in a nulling mode. The nulling technique is the sparse aperture equivalent of the conventional coronagraphic technique used in filled aperture telescopes. In this mode the stellar light itself is suppressed by a destructive fringe, effectively enhancing the contrast of the circumstellar material located near the star. By fitting the unique KIN data, we have obtained an angular size of the mid-infrared continuum emitting material of 6.2, 4.0, or 5.4 mas for a disk profile, Gaussian profile (FWHM), and shell profile, respectively. The data show evidence of enhanced neutral atomic hydrogen emission and atomic metals including silicon located in the inner spatial regime near the white dwarf (WD) relative to the outer regime. There are also nebular emission lines and evidence of hot silicate dust in the outer spatial region, centered at ~17 AU from the WD, that are not found in the inner regime. Our evidence suggests that these features have been excited by the nova flash in the outer spatial regime before the blast wave reached these regions. These identifications support a model in which the dust appears to be present between outbursts and is not created during the outburst event. We further discuss the present results in terms of a unifying model of the system that includes an increase in density in the plane of the orbit of the two stars created by a spiral shock wave caused by the motion of the stars through the cool wind of the red giant star.", "doi": "10.1086/529422", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2008-04-20", "series_number": "2", "volume": "677", "issue": "2", "pages": "1253-1267" } ]