[ { "id": "authors:ek2kh-tb789", "collection": "authors", "collection_id": "ek2kh-tb789", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190619-084158876", "type": "publication_whitepaper", "title": "Imaging Giant Protoplanets with the ELTs", "author": [ { "family_name": "Sallum", "given_name": "Steph", "clpid": "Sallum-S" }, { "family_name": "Bailey", "given_name": "Vanessa P.", "orcid": "0000-0002-5407-2806", "clpid": "Bailey-V-P" }, { "family_name": "Bernstein", "given_name": "Rebecca A.", "clpid": "Bernstein-R-A" }, { "family_name": "Boss", "given_name": "Alan P.", "clpid": "Boss-A-P" }, { "family_name": "Bowler", "given_name": "Brendan P.", "orcid": "0000-0003-2649-2288", "clpid": "Bowler-B-P" }, { "family_name": "Close", "given_name": "Laird", "orcid": "0000-0002-2167-8246", "clpid": "Close-L-M" }, { "family_name": "Currie", "given_name": "Thayne", "orcid": "0000-0002-7405-3119", "clpid": "Currie-T" }, { "family_name": "Dong", "given_name": "Ruobing", "orcid": "0000-0001-9290-7846", "clpid": "Dong-Ruobing" }, { "family_name": "Espaillat", "given_name": "Catherine", "orcid": "0000-0001-9227-5949", "clpid": "Espaillat-C-C" }, { "family_name": "Fitzgerald", "given_name": "Michael P.", "orcid": "0000-0002-0176-8973", "clpid": "Fitzgerald-M-P" }, { "family_name": "Follette", "given_name": "Katherine B.", "clpid": "Follette-K-B" }, { "family_name": "Fortney", "given_name": "Jonathan", "orcid": "0000-0002-9843-4354", "clpid": "Fortney-J-J" }, { "family_name": "Hasegawa", "given_name": "Yasuhiro", "orcid": "0000-0002-9017-3663", "clpid": "Hasegawa-Yasuhiro" }, { "family_name": "Jang-Condell", "given_name": "Hannah", "clpid": "Jang-Condell-H" }, { "family_name": "Jovanovic", "given_name": "Nemanja", "clpid": "Jovanovic-N" }, { "family_name": "Kane", "given_name": "Stephen R.", "orcid": "0000-0002-7084-0529", "clpid": "Kane-S-R" }, { "family_name": "Konopacky", "given_name": "Quinn", "orcid": "0000-0002-9936-6285", "clpid": "Konopacky-Q-M" }, { "family_name": "Liu", "given_name": "Michael", "orcid": "0000-0003-2232-7664", "clpid": "Liu-Michael-C" }, { "family_name": "Lozi", "given_name": "Julien", "orcid": "0000-0002-3047-1845", "clpid": "Lozi-J" }, { "family_name": "Males", "given_name": "Jared", "clpid": "Males-J-R" }, { "family_name": "Mawet", "given_name": "Dimitri", "orcid": "0000-0002-8895-4735", "clpid": "Mawet-D" }, { "family_name": "Mazin", "given_name": "Benjamin", "clpid": "Mazin-B-A" }, { "family_name": "Millar-Blanchaer", "given_name": "Max", "orcid": "0000-0001-6205-9233", "clpid": "Millar-Blanchaer-M-A" }, { "family_name": "Murray-Clay", "given_name": "Ruth", "orcid": "0000-0001-5061-0462", "clpid": "Murray-Clay-R-A" }, { "family_name": "Ruane", "given_name": "Garreth", "orcid": "0000-0003-4769-1665", "clpid": "Ruane-G-J" }, { "family_name": "Skemer", "given_name": "Andrew", "orcid": "0000-0001-6098-3924", "clpid": "Skemer-A-J" }, { "family_name": "Tamura", "given_name": "Motohide", "orcid": "0000-0002-6510-0681", "clpid": "Tamura-Motohide" }, { "family_name": "Vasisht", "given_name": "Gautam", "orcid": "0000-0002-1871-6264", "clpid": "Vasisht-G" }, { "family_name": "Wang", "given_name": "Jason", "orcid": "0000-0003-0774-6502", "clpid": "Wang-Jason-J" }, { "family_name": "Wang", "given_name": "Ji", "orcid": "0000-0002-4361-8885", "clpid": "Wang-Ji" } ], "abstract": "We have now accumulated a wealth of observations of the planet-formation environment and of mature planetary systems. These data allow us to test and refine theories of gas-giant planet formation by placing constraints on the conditions and timescale of this process. Yet a number of fundamental questions remain unanswered about how protoplanets accumulate material, their photospheric properties and compositions, and how they interact with protoplanetary disks. While we have begun to detect protoplanet candidates during the last several years, we are presently only sensitive to the widest separation, highest mass / accretion rate cases. Current observing facilities lack the angular resolution and inner working angle to probe the few-AU orbital separations where giant planet formation is thought to be most efficient. They also lack the contrast to detect accretion rates that would form lower mass gas giants and ice giants. Instruments and telescopes coming online over the next decade will provide high contrast in the inner giant-planet-forming regions around young stars, allowing us to build a protoplanet census and to characterize planet formation in detail for the first time.", "doi": "10.48550/arXiv.1903.05319", "publisher": "arXiv", "publication_date": "2019-03-13" }, { "id": "authors:vtwey-01v65", "collection": "authors", "collection_id": "vtwey-01v65", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20181203-133957018", "type": "monograph", "title": "Direct Imaging in Reflected Light: Characterization of Older, Temperate Exoplanets With 30-m Telescopes", "author": [ { "family_name": "Artigau", "given_name": "\u00c9tienne", "orcid": "0000-0003-3506-5667", "clpid": "Artigau-E" }, { "family_name": "Bernstein", "given_name": "Rebecca A.", "clpid": "Bernstein-R-A" }, { "family_name": "Brandt", "given_name": "Timothy", "orcid": "0000-0003-2630-8073", "clpid": "Brandt-T-D" }, { "family_name": "Chilcote", "given_name": "Jeffrey", "orcid": "0000-0001-6305-7272", "clpid": "Chilcote-J-K" }, { "family_name": "Close", "given_name": "Laird", "orcid": "0000-0002-2167-8246", "clpid": "Close-L-M" }, { "family_name": "Crossfield", "given_name": "Ian", "orcid": "0000-0002-1835-1891", "clpid": "Crossfield-I-J-M" }, { "family_name": "Delorme", "given_name": "Jacques-Robert", "clpid": "Delorme-J-R" }, { "family_name": "Dressing", "given_name": "Courtney", "orcid": "0000-0001-8189-0233", "clpid": "Dressing-C-D" }, { "family_name": "Fitzgerald", "given_name": "Michael P.", "orcid": "0000-0002-0176-8973", "clpid": "Fitzgerald-M-P" }, { "family_name": "Fortney", "given_name": "Jonathan", "orcid": "0000-0002-9843-4354", "clpid": "Fortney-J-J" }, { "family_name": "Howard", "given_name": "Andrew", "orcid": "0000-0001-8638-0320", "clpid": "Howard-A-W" }, { "family_name": "Frazin", "given_name": "Richard", "clpid": "Frazin-R" }, { "family_name": "Jovanovic", "given_name": "Nemanja", "clpid": "Jovanovic-N" }, { "family_name": "Konopacky", "given_name": "Quinn", "orcid": "0000-0002-9936-6285", "clpid": "Konopacky-Q-M" }, { "family_name": "Lozi", "given_name": "Julien", "orcid": "0000-0002-3047-1845", "clpid": "Lozi-J" }, { "family_name": "Males", "given_name": "Jared R.", "clpid": "Males-J-R" }, { "family_name": "Marois", "given_name": "Christian", "orcid": "0000-0002-4164-4182", "clpid": "Marois-C" }, { "family_name": "Mazin", "given_name": "Benjamin A.", "clpid": "Mazin-B-A" }, { "family_name": "Millar-Blanchaer", "given_name": "Max A.", "orcid": "0000-0001-6205-9233", "clpid": "Millar-Blanchaer-M-A" }, { "family_name": "Morzinski", "given_name": "Katie M.", "clpid": "Morzinski-K-M" }, { "family_name": "Roberts", "given_name": "Lewis", "orcid": "0000-0003-3892-2900", "clpid": "Roberts-L-C-Jr" }, { "family_name": "Serabyn", "given_name": "Eugene", "clpid": "Serabyn-E" }, { "family_name": "Vasisht", "given_name": "Gautam", "orcid": "0000-0002-1871-6264", "clpid": "Vasisht-G" }, { "family_name": "Wallace", "given_name": "J. Kent", "clpid": "Wallace-J-K" }, { "family_name": "Wang", "given_name": "Ji", "orcid": "0000-0002-4361-8885", "clpid": "Wang-Ji" } ], "abstract": "Direct detection, also known as direct imaging, is a method for discovering and characterizing the atmospheres of planets at intermediate and wide separations. It is the only means of obtaining spectra of non-transiting exoplanets. Characterizing the atmospheres of planets in the <5 AU regime, where RV surveys have revealed an abundance of other worlds, requires a 30-m-class aperture in combination with an advanced adaptive optics system, coronagraph, and suite of spectrometers and imagers - this concept underlies planned instruments for both TMT (the Planetary Systems Imager, or PSI) and the GMT (GMagAO-X). These instruments could provide astrometry, photometry, and spectroscopy of an unprecedented sample of rocky planets, ice giants, and gas giants. For the first time habitable zone exoplanets will become accessible to direct imaging, and these instruments have the potential to detect and characterize the innermost regions of nearby M-dwarf planetary systems in reflected light. High-resolution spectroscopy will not only illuminate the physics and chemistry of exo-atmospheres, but may also probe rocky, temperate worlds for signs of life in the form of atmospheric biomarkers (combinations of water, oxygen and other molecular species). By completing the census of non-transiting worlds at a range of separations from their host stars, these instruments will provide the final pieces to the puzzle of planetary demographics. This whitepaper explores the science goals of direct imaging on 30-m telescopes and the technology development needed to achieve them.", "doi": "10.48550/arXiv.1808.09632", "publisher": "arXiv", "publication_date": "2018-08-29" }, { "id": "authors:j33y3-th302", "collection": "authors", "collection_id": "j33y3-th302", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20171017-111646452", "type": "article", "title": "Light curves of the neutron star merger GW170817/SSS17a: Implications for r-process nucleosynthesis", "author": [ { "family_name": "Drout", "given_name": "M. R.", "orcid": "0000-0001-7081-0082", "clpid": "Drout-M-R" }, { "family_name": "Piro", "given_name": "A. L.", "orcid": "0000-0001-6806-0673", "clpid": "Piro-A-L" }, { "family_name": "Shappee", "given_name": "B. J.", "orcid": "0000-0003-4631-1149", "clpid": "Shappee-B-J" }, { "family_name": "Kilpatrick", "given_name": "C. D.", "orcid": "0000-0002-5740-7747", "clpid": "Kilpatrick-C-D" }, { "family_name": "Simon", "given_name": "J. D.", "clpid": "Simon-J-D" }, { "family_name": "Contreras", "given_name": "C.", "clpid": "Contreras-C" }, { "family_name": "Coulter", "given_name": "D. A.", "clpid": "Coulter-D-A" }, { "family_name": "Foley", "given_name": "R. J.", "clpid": "Foley-R-J" }, { "family_name": "Siebert", "given_name": "M. R.", "clpid": "Siebert-M-R" }, { "family_name": "Morrell", "given_name": "N.", "orcid": "0000-0003-2535-3091", "clpid": "Morrell-N" }, { "family_name": "Boutsia", "given_name": "K.", "clpid": "Boutsia-K" }, { "family_name": "Di Mille", "given_name": "F.", "clpid": "Di-Mille-F" }, { "family_name": "Holoien", "given_name": "T. W.-S.", "orcid": "0000-0001-9206-3460", "clpid": "Holoien-T-W-S" }, { "family_name": "Kasen", "given_name": "D.", "clpid": "Kasen-D" }, { "family_name": "Kollmeier", "given_name": "J. A.", "orcid": "0000-0001-9852-1610", "clpid": "Kollmeier-J-A" }, { "family_name": "Madore", "given_name": "B. F.", "orcid": "0000-0002-1576-1676", "clpid": "Madore-B-F" }, { "family_name": "Monson", "given_name": "A. J.", "orcid": "0000-0002-0048-2586", "clpid": "Monson-A-J" }, { "family_name": "Murguia-Berthier", "given_name": "A.", "clpid": "Murguia-Berthier-A" }, { "family_name": "Pan", "given_name": "Y.-C.", "clpid": "Pan-Y-C" }, { "family_name": "Prochaska", "given_name": "J. X.", "orcid": "0000-0002-7738-6875", "clpid": "Prochaska-J-X" }, { "family_name": "Ramirez-Ruiz", "given_name": "E.", "orcid": "0000-0003-2558-3102", "clpid": "Ramirez-Ruiz-E" }, { "family_name": "Rest", "given_name": "A.", "clpid": "Rest-A" }, { "family_name": "Adams", "given_name": "C.", "clpid": "Adams-C" }, { "family_name": "Alatalo", "given_name": "K.", "orcid": "0000-0002-4261-2326", "clpid": "Alatalo-K" }, { "family_name": "Ba\u00f1ados", "given_name": "E.", "orcid": "0000-0002-2931-7824", "clpid": "Ba\u00f1ados-E" }, { "family_name": "Baughman", "given_name": "J.", "clpid": "Baughman-J" }, { "family_name": "Beers", "given_name": "T. C.", "orcid": "0000-0003-4573-6233", "clpid": "Beers-T-C" }, { "family_name": "Bernstein", "given_name": "R. A.", "clpid": "Bernstein-R-A" }, { "family_name": "Bitsakis", "given_name": "T.", "orcid": "0000-0001-5787-8242", "clpid": "Bitsakis-T" }, { "family_name": "Campillay", "given_name": "A.", "clpid": "Campillay-A" }, { "family_name": "Hansen", "given_name": "T. T.", "clpid": "Hansen-T-T" }, { "family_name": "Higgs", "given_name": "C. R.", "clpid": "Higgs-C-R" }, { "family_name": "Ji", "given_name": "A. P.", "clpid": "Ji-A-P" }, { "family_name": "Maravelias", "given_name": "G.", "clpid": "Maravelias-G" }, { "family_name": "Marshall", "given_name": "J. L.", "clpid": "Marshall-J-L" }, { "family_name": "Bidin", "given_name": "C. Moni", "clpid": "Bidin-C-M" }, { "family_name": "Prieto", "given_name": "J. L.", "orcid": "0000-0003-0943-0026", "clpid": "Prieto-J-L" }, { "family_name": "Rasmussen", "given_name": "K. C.", "clpid": "Rasmussen-K-C" }, { "family_name": "Rojas-Bravo", "given_name": "C.", "clpid": "Rojas-Bravo-C" }, { "family_name": "Strom", "given_name": "A. L.", "orcid": "0000-0001-6369-1636", "clpid": "Strom-A-L" }, { "family_name": "Ulloa", "given_name": "N.", "clpid": "Ulloa-N" }, { "family_name": "Vargas-Gonz\u00e1lez", "given_name": "J.", "clpid": "Vargas-Gonz\u00e1lez-J" }, { "family_name": "Wan", "given_name": "Z.", "clpid": "Wan-Z" }, { "family_name": "Whitten", "given_name": "D. D.", "orcid": "0000-0002-9594-6143", "clpid": "Whitten-D-D" } ], "abstract": "On 17 August 2017, gravitational waves were detected from a binary neutron star merger, GW170817, along with a coincident short gamma-ray burst, GRB170817A. An optical transient source, Swope Supernova Survey 17a (SSS17a), was subsequently identified as the counterpart of this event. We present ultraviolet, optical, and infrared light curves of SSS17a extending from 10.9 hours to 18 days post-merger. We constrain the radioactively powered transient resulting from the ejection of neutron-rich material. The fast rise of the light curves, subsequent decay, and rapid color evolution are consistent with multiple ejecta components of differing lanthanide abundance. The late-time light curve indicates that SSS17a produced at least ~0.05 solar masses of heavy elements, demonstrating that neutron star mergers play a role in r-process nucleosynthesis in the universe.", "doi": "10.1126/science.aaq0049", "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": "1570-1574" }, { "id": "authors:k4156-wpb96", "collection": "authors", "collection_id": "k4156-wpb96", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20171017-111646188", "type": "article", "title": "Early spectra of the gravitational wave source GW170817: Evolution of a neutron star merger", "author": [ { "family_name": "Shappee", "given_name": "B. J.", "orcid": "0000-0003-4631-1149", "clpid": "Shappee-B-J" }, { "family_name": "Simon", "given_name": "J. D.", "clpid": "Simon-J-D" }, { "family_name": "Drout", "given_name": "M. R.", "orcid": "0000-0001-7081-0082", "clpid": "Drout-M-R" }, { "family_name": "Piro", "given_name": "A. L.", "orcid": "0000-0001-6806-0673", "clpid": "Piro-A-L" }, { "family_name": "Morrell", "given_name": "N.", "orcid": "0000-0003-2535-3091", "clpid": "Morrell-N" }, { "family_name": "Prieto", "given_name": "J. L.", "orcid": "0000-0003-1072-2712", "clpid": "Prieto-J-L-ASTRO" }, { "family_name": "Kasen", "given_name": "D.", "clpid": "Kasen-D" }, { "family_name": "Holoien", "given_name": "T. W.-S.", "orcid": "0000-0001-9206-3460", "clpid": "Holoien-T-W-S" }, { "family_name": "Kollmeier", "given_name": "J. A.", "orcid": "0000-0001-9852-1610", "clpid": "Kollmeier-J-A" }, { "family_name": "Kelson", "given_name": "D. D.", "clpid": "Kelson-D-D" }, { "family_name": "Coulter", "given_name": "D. A.", "clpid": "Coulter-D-A" }, { "family_name": "Foley", "given_name": "R. J.", "clpid": "Foley-R-J" }, { "family_name": "Kilpatrick", "given_name": "C. D.", "orcid": "0000-0002-5740-7747", "clpid": "Kilpatrick-C-D" }, { "family_name": "Siebert", "given_name": "M. R.", "clpid": "Siebert-M-R" }, { "family_name": "Madore", "given_name": "B. F.", "orcid": "0000-0002-1576-1676", "clpid": "Madore-B-F" }, { "family_name": "Murguia-Berthier", "given_name": "A.", "clpid": "Murguia-Berthier-A" }, { "family_name": "Pan", "given_name": "Y.-C.", "clpid": "Pan-Y-C" }, { "family_name": "Prochaska", "given_name": "J. X.", "orcid": "0000-0002-7738-6875", "clpid": "Prochaska-J-X" }, { "family_name": "Ramirez-Ruiz", "given_name": "E.", "orcid": "0000-0003-2558-3102", "clpid": "Ramirez-Ruiz-E" }, { "family_name": "Rest", "given_name": "A.", "clpid": "Rest-A" }, { "family_name": "Adams", "given_name": "C.", "clpid": "Adams-C" }, { "family_name": "Alatalo", "given_name": "K.", "orcid": "0000-0002-4261-2326", "clpid": "Alatalo-K" }, { "family_name": "Ba\u00f1ados", "given_name": "E.", "orcid": "0000-0002-2931-7824", "clpid": "Ba\u00f1ados-E" }, { "family_name": "Baughman", "given_name": "J.", "clpid": "Baughman-J" }, { "family_name": "Bernstein", "given_name": "R. A.", "clpid": "Bernstein-R-A" }, { "family_name": "Bitsakis", "given_name": "T.", "orcid": "0000-0001-5787-8242", "clpid": "Bitsakis-T" }, { "family_name": "Boutsia", "given_name": "K.", "clpid": "Boutsia-K" }, { "family_name": "Bravo", "given_name": "J. R.", "clpid": "Bravo-J-R" }, { "family_name": "Di Mille", "given_name": "F.", "clpid": "Di-Mille-F" }, { "family_name": "Higgs", "given_name": "C. R.", "clpid": "Higgs-C-R" }, { "family_name": "Ji", "given_name": "A. P.", "clpid": "Ji-A-P" }, { "family_name": "Maravelias", "given_name": "G.", "clpid": "Maravelias-G" }, { "family_name": "Marshall", "given_name": "J. L.", "clpid": "Marshall-J-L" }, { "family_name": "Placco", "given_name": "V. M.", "orcid": "0000-0003-4479-1265", "clpid": "Placco-V-M" }, { "family_name": "Prieto", "given_name": "G.", "clpid": "Prieto-G" }, { "family_name": "Wan", "given_name": "Z.", "clpid": "Wan-Z" } ], "abstract": "On 17 August 2017, Swope Supernova Survey 2017a (SSS17a) was discovered as the optical counterpart of the binary neutron star gravitational wave event GW170817. We report time-series spectroscopy of SSS17a from 11.75 hours until 8.5 days after merger. Over the first hour of observations the ejecta rapidly expanded and cooled. Applying blackbody fits to the spectra, we measure the photosphere cooling from 11,000^(+3400)_(-900) K to 9300^(+300)_(-300) K, and determine a photospheric velocity of roughly 30% of the speed of light. The spectra of SSS17a begin displaying broad features after 1.46 days, and evolve qualitatively over each subsequent day, with distinct blue (early-time) and red (late-time) components. The late-time component is consistent with theoretical models of r-process-enriched neutron star ejecta, whereas the blue component requires high velocity, lanthanide-free material.", "doi": "10.1126/science.aaq0186", "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": "1574-1578" }, { "id": "authors:ght8j-k5q83", "collection": "authors", "collection_id": "ght8j-k5q83", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150115-104353320", "type": "article", "title": "The Detailed Chemical Properties of M31 Star Clusters. I. Fe, Alpha and Light Elements", "author": [ { "family_name": "Colucci", "given_name": "Janet E.", "clpid": "Colucci-J-E" }, { "family_name": "Bernstein", "given_name": "Rebecca A.", "clpid": "Bernstein-R-A" }, { "family_name": "Cohen", "given_name": "Judith G.", "orcid": "0000-0002-8039-4673", "clpid": "Cohen-J-G" } ], "abstract": "We present ages, Fe/H] and abundances of the a elements Ca I, Si I, Ti I, Ti II, and light elements Mg I, Na I, and Al I for 31 globular clusters (GCs) in M31, which were obtained from high-resolution, high signal-to-noise ratio > 60 echelle spectra of their integrated light (IL). All abundances and ages are obtained using our original technique for high-resolution IL abundance analysis of GCs. This sample provides a never before seen picture of the chemical history of M31. The GCs are dispersed throughout the inner and outer halo, from 2.5 kpc < R_(M31) < 117 kpc. We find a range of Fe/H] within 20 kpc of the center of M31, and a constant Fe/H] ~-1.6 for the outer halo clusters. We find evidence for at least one massive GC in M31 with an age between 1 and 5 Gyr. The \u0251-element ratios are generally similar to the Milky Way GC and field star ratios. We also find chemical evidence for a late-time accretion origin for at least one cluster, which has a different abundance pattern than other clusters at similar metallicity. We find evidence for star-to-star abundance variations in Mg, Na, and Al in the GCs in our sample, and find correlations of Ca, Mg, Na, and possibly Al abundance ratios with cluster luminosity and velocity dispersion, which can potentially be used to constrain GC self-enrichment scenarios. Data presented here were obtained with the HIRES echelle spectrograph on the Keck I telescope.", "doi": "10.1088/0004-637X/797/2/116", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2014-12-20", "series_number": "2", "volume": "797", "issue": "2", "pages": "Art. No. 116" }, { "id": "authors:8a34w-kzn48", "collection": "authors", "collection_id": "8a34w-kzn48", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190521-161105416", "type": "article", "title": "Extragalactic Globular Cluster Populations from High Resolution Integrated Light Spectra", "author": [ { "family_name": "Colucci", "given_name": "J. E.", "clpid": "Colucci-J-E" }, { "family_name": "Bernstein", "given_name": "R. A.", "clpid": "Bernstein-R-A" }, { "family_name": "McWilliam", "given_name": "A.", "clpid": "McWilliam-A" }, { "family_name": "Cohen", "given_name": "J. G.", "orcid": "0000-0002-8039-4673", "clpid": "Cohen-J-G" } ], "abstract": "We present a comparison of high-resolution, integrated-light, detailed chemical abundances for Galactic and extragalactic globular clusters in both massive galaxies and dwarf galaxies. We include measurements of Fe, Ca, Si, Na, and Al for globular cluster samples in the Milky Way, M31, Large Magellanic Cloud, and NGC 5128. These and other recent results from our group on M31 and NGC 5128 are the first chemical abundances derived from discrete absorption features in old stars beyond the Milky Way and its nearest neighbors. These abundances can provide both galaxy enrichment histories and constraints on globular cluster formation and evolution.", "doi": "10.48550/arXiv.1302.6252", "issn": "0037-8720", "publisher": "Societ\u00e0 Astronomica Italiana", "publication": "Memorie della Societ\u00e0 Astronomica Italiana", "publication_date": "2013", "series_number": "1", "volume": "84", "issue": "1", "pages": "50-53" }, { "id": "authors:xb1kw-e4k82", "collection": "authors", "collection_id": "xb1kw-e4k82", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20091110-184457688", "type": "article", "title": "M31 Globular Cluster Abundances from High-Resolution, Integrated-Light Spectroscopy", "author": [ { "family_name": "Colucci", "given_name": "Janet E.", "clpid": "Colucci-J-E" }, { "family_name": "Bernstein", "given_name": "Rebecca A.", "clpid": "Bernstein-R-A" }, { "family_name": "Cameron", "given_name": "Scott", "clpid": "Cameron-S" }, { "family_name": "McWilliam", "given_name": "Andrew", "clpid": "McWilliam-A" }, { "family_name": "Cohen", "given_name": "Judith G.", "orcid": "0000-0002-8039-4673", "clpid": "Cohen-J-G" } ], "abstract": "We report the first detailed chemical abundances for five globular clusters (GCs) in M31 from high-resolution (R ~ 25,000) spectroscopy of their integrated light (IL). These GCs are the first in a larger set of clusters observed as part of an ongoing project to study the formation history of M31 and its GC population. The data presented here were obtained with the HIRES echelle spectrograph on the Keck I telescope and are analyzed using a new IL spectra analysis method that we have developed. In these clusters, we measure abundances for Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Y, and Ba, ages \u226510 Gyr, and a range in [Fe/H] of \u20130.9 to \u20132.2. As is typical of Milky Way GCs, we find these M31 GCs to be enhanced in the \u03b1-elements Ca, Si, and Ti relative to Fe. We also find [Mg/Fe] to be low relative to other [\u03b1/Fe], and [Al/Fe] to be enhanced in the IL abundances. These results imply that abundances of Mg, Al (and likely O, Na) recovered from IL do display the inter- and intra-cluster abundance variations seen in individual Milky Way GC stars, and that special care should be taken in the future in interpreting low- or high-resolution IL abundances of GCs that are based on Mg-dominated absorption features. Fe-peak and the neutron-capture elements Ba and Y also follow Milky Way abundance trends. We also present high-precision velocity dispersion measurements for all five M31 GCs, as well as independent constraints on the reddening toward the clusters from our analysis.", "doi": "10.1088/0004-637X/704/1/385", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2009-10-10", "series_number": "1", "volume": "704", "issue": "1", "pages": "385-414" }, { "id": "authors:350ab-45055", "collection": "authors", "collection_id": "350ab-45055", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100310-112216870", "type": "article", "title": "Diffuse Optical Light in Galaxy Clusters. II. Correlations with Cluster Properties", "author": [ { "family_name": "Krick", "given_name": "J. E.", "clpid": "Krick-J-E" }, { "family_name": "Bernstein", "given_name": "R. A.", "clpid": "Bernstein-R-A" } ], "abstract": "We have measured the flux, profile, color, and substructure in the diffuse intracluster light (ICL) in a sample of 10 galaxy clusters with a range of mass, morphology, redshift, and density. Deep, wide-field observations for this project were made in two bands at the 1 m Swope and 2.5 m du Pont telescopes at Las Campanas Observatory. Careful attention in reduction and analysis was paid to the illumination correction, background subtraction, point-spread function determination, and galaxy subtraction. ICL flux is detected in both bands in all 10 clusters ranging from 7.6 \u00d7 10^(10) to 7.0 \u00d7 10^(11) h^(-1)_(70) L_\u2299 in r and 1.4 \u00d7 10^(10) to 1.2 \u00d7 10^(11) h^(-1)_(70) L_\u2299 in the B band. These fluxes account for 6%-22% of the total cluster light within one-quarter of the virial radius in r and 4%-21% in the B band. Average ICL B - r colors range from 1.5 to 2.8 mag when k- and evolution corrected to the present epoch. In several clusters we also detect ICL in group environments near the cluster center and up to 1 h^(-1)_(70) Mpc distant from the cluster center. Our sample, having been selected from the Abell sample, is incomplete in that it does not include high-redshift clusters with low density, low flux, or low mass, and it does not include low-redshift clusters with high flux, high mass, or high density. This bias makes it difficult to interpret correlations between ICL flux and cluster properties. Despite this selection bias, we do find that the presence of a cD galaxy corresponds to both centrally concentrated galaxy profiles and centrally concentrated ICL profiles. This is consistent with ICL either forming from galaxy interactions at the center or forming at earlier times in groups and later combining in the center.", "doi": "10.1086/518787", "issn": "0004-6256", "publisher": "American Astronomical Society", "publication": "Astronomical Journal", "publication_date": "2007-08", "series_number": "2", "volume": "134", "issue": "2", "pages": "466-493" } ]