[ { "id": "authors:yrmtg-4vr87", "collection": "authors", "collection_id": "yrmtg-4vr87", "cite_using_url": "https://authors.library.caltech.edu/records/yrmtg-4vr87", "type": "article", "title": "A Steadily Declining Dispersion Measure for the Repeating Fast Radio Burst FRB 20220529A: Evidence for a Fast Radio Burst Engine Embedded in an Expanding Supernova Remnant", "author": [ { "family_name": "Pandhi", "given_name": "Ayush", "orcid": "0000-0002-8897-1973" }, { "family_name": "Nimmo", "given_name": "Kenzie", "orcid": "0000-0003-0510-0740" }, { "family_name": "Andrew", "given_name": "Shion", "orcid": "0000-0002-3980-815X" }, { "family_name": "Brar", "given_name": "Charanjot", "orcid": "0000-0002-1800-8233" }, { "family_name": "Chatterjee", "given_name": "Shami", "orcid": "0000-0002-2878-1502" }, { "family_name": "Cook", "given_name": "Amanda M.", "orcid": "0000-0001-6422-8125" }, { "family_name": "Curtin", "given_name": "Alice", "orcid": "0000-0002-8376-1563" }, { "family_name": "Gaensler", "given_name": "B. M.", "orcid": "0000-0002-3382-9558" }, { "family_name": "Gawronski", "given_name": "Marcin", "orcid": "0000-0003-4056-4903" }, { "family_name": "Hessels", "given_name": "Jason", "orcid": "0000-0003-2317-1446" }, { "family_name": "Kaspi", "given_name": "Victoria M.", "orcid": "0000-0001-9345-0307" }, { "family_name": "Khan", "given_name": "Afrokk", "orcid": "0009-0004-4176-0062" }, { "family_name": "Kirsten", "given_name": "Franz", "orcid": "0000-0001-6664-8668" }, { "family_name": "Lazda", "given_name": "Mattias", "orcid": "0000-0002-5857-4264" }, { "family_name": "Leung", "given_name": "Calvin", "orcid": "0000-0002-4209-7408" }, { "family_name": "Main", "given_name": "Robert", "orcid": "0000-0002-7164-9507" }, { "family_name": "Masui", "given_name": "Kiyoshi W.", "orcid": "0000-0002-4279-6946" }, { "family_name": "Mckinven", "given_name": "Ryan", "orcid": "0000-0001-7348-6900" }, { "family_name": "Michilli", "given_name": "Daniele", "orcid": "0000-0002-2551-7554" }, { "family_name": "Ng", "given_name": "Mason", "orcid": "0000-0002-0940-6563" }, { "family_name": "Ould-Boukattine", "given_name": "Omar", "orcid": "0000-0001-9381-8466" }, { "family_name": "Pearlman", "given_name": "Aaron B.", "orcid": "0000-0002-8912-0732" }, { "family_name": "Pleunis", "given_name": "Ziggy", "orcid": "0000-0002-4795-697X" }, { "family_name": "Pollak", "given_name": "Alexander W.", "orcid": "0000-0002-3430-7671" }, { "family_name": "Pradeep E. T.", "given_name": "Sachin", "orcid": "0009-0008-2000-6959" }, { "family_name": "Puchalska", "given_name": "Weronika", "orcid": "0000-0003-2422-6605" }, { "family_name": "Sammons", "given_name": "Mawson W.", "orcid": "0000-0002-4623-5329" }, { "family_name": "Scholz", "given_name": "Paul", "orcid": "0000-0002-7374-7119" }, { "family_name": "Shah", "given_name": "Vishwangi", "orcid": "0000-0002-4823-1946" }, { "family_name": "Shin", "given_name": "Kaitlyn", "orcid": "0000-0002-6823-2073", "clpid": "Shin-Kaitlyn" }, { "family_name": "Siegel", "given_name": "Seth R.", "orcid": "0000-0003-2631-6217" }, { "family_name": "Smith", "given_name": "Kendrick", "orcid": "0000-0002-2088-3125" } ], "abstract": "
\n

We present the discovery and subsequent 3.2 yr monitoring campaign of the repeating fast radio burst (FRB) FRB 20220529A with CHIME/FRB. We observe a gradual decline in dispersion measure (DM) of −0.881 ± 0.001 pc cm−3 yr−1 (−1.235 ± 0.001 pc cm−3 yr−1 in the rest frame), implying a ≥3.5% ± 0.2% decrease in the total electron column in the source environment, and we see scattering timescale variations over weeks to years. We observe a short-lived excursion in which the DM rises by ∼1 pc cm−3, immediately preceding an increase in transient Faraday rotation measure (RM) of ∼2000 rad m−2 previously reported for this source, before returning to its gradual decline in DM. During this DM/RM excursion, we identify a local line-of-sight magnetic field of 3.4 ± 0.2 mG around FRB 20220529A, corresponding to one of the most strongly magnetized FRB environments. We measure a decrease in the linear polarization fraction of FRB 20220529A bursts with decreasing frequency that we attribute to depolarization from multipath propagation in the source environment. We also place a 5σ upper limit on the spectral luminosity of an associated persistent radio source of ≤5 × 1028 erg s−1 Hz−1 at 1.5 GHz. These observations are consistent with FRB 20220529A originating from a young (approximately years to centuries old) expanding supernova remnant, with short-lived DM and RM variability arising from interactions with the supernova remnant or with a binary companion.

\n
", "doi": "10.3847/2041-8213/ae52f8", "issn": "2041-8205", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal Letters", "publication_date": "2026-04-01", "series_number": "2", "volume": "1000", "issue": "2", "pages": "L53" }, { "id": "authors:5vc8a-bb458", "collection": "authors", "collection_id": "5vc8a-bb458", "cite_using_url": "https://authors.library.caltech.edu/records/5vc8a-bb458", "type": "article", "title": "Deep Synoptic Array Science: Searching for Long Duration Radio Transients with the DSA-110", "author": [ { "family_name": "Sherman", "given_name": "Myles B.", "orcid": "0000-0002-6573-7316", "clpid": "Sherman-Myles-B" }, { "family_name": "Kosogorov", "given_name": "Nikita", "orcid": "0000-0003-1226-118X", "clpid": "Kosogorov-Nikita" }, { "family_name": "Law", "given_name": "Casey", "orcid": "0000-0002-4119-9963", "clpid": "Law-Casey" }, { "family_name": "Ravi", "given_name": "Vikram", "orcid": "0000-0002-7252-5485", "clpid": "Ravi-Vikram" }, { "family_name": "Faber", "given_name": "Jakob T.", "orcid": "0000-0001-9855-5781", "clpid": "Faber-Jakob-T" }, { "family_name": "Ocker", "given_name": "Stella K.", "orcid": "0000-0002-4941-5333", "clpid": "Ocker-Stella-K" }, { "family_name": "Connor", "given_name": "Liam", "orcid": "0000-0002-7587-6352" }, { "family_name": "Qu", "given_name": "Yuanhong", "orcid": "0000-0003-4721-4869" }, { "family_name": "Shin", "given_name": "Kaitlyn", "orcid": "0000-0002-6823-2073", "clpid": "Shin-Kaitlyn" }, { "family_name": "Sharma", "given_name": "Kritti", "orcid": "0000-0002-4477-3625", "clpid": "Sharma-Kritti" }, { "family_name": "Sanghavi", "given_name": "Pranav", "orcid": "0000-0001-5504-229X" }, { "family_name": "Hallinan", "given_name": "Gregg", "orcid": "0000-0002-7083-4049", "clpid": "Hallinan-G" }, { "family_name": "Hodges", "given_name": "Mark", "clpid": "Hodges-Mark" }, { "literal": "The Deep Synoptic Array team" } ], "abstract": "

We describe the design and commissioning tests for the DSA-110 Not-So-Fast Radio Burst (NSFRB) search pipeline, a 1.4 GHz image-plane single-pulse search sensitive to 134 ms−160.8 s radio bursts. Extending the pulse width range of the Fast Radio Burst search by 3 orders of magnitude, the NSFRB search is sensitive to the recently discovered Galactic Long Period Radio Transients (LPRTs or LPTs). The NSFRB search operates in real-time, utilizing a custom GPU-accelerated search code, cerberus, implemented in Python with JAX. We summarize successful commissioning sensitivity tests with continuum sources and pulsar B0329+54, estimating the 90% completeness 25σ flux (fluence) limit to be ∼1200 mJy (∼160 Jy ms). Future tests of recovery of longer timescale transients, e.g., CHIME J1634+44, are planned to supplement injection testing and B0329+54 observations. An offline DSA-110 NSFRB Galactic Plane Survey was conducted to search for LPRTs, covering −3:5 < b < 5:7 and 141° < l < 225° (∼770 square degrees) in Galactic coordinates. We estimate an upper limit Poissonian burst rate ∼2 hr−1 per square degree (∼17 hr−1 per 3° × 3° survey grid cell) maximized across the inner \u2223b\u2223 < 0:25 of the surveyed region. By imposing the ∼1200 mJy flux limit on two representative models (the magnetar plastic flow model and the White Dwarf-M Dwarf binary model), we reject with 95% confidence the presence of White Dwarf-M Dwarf binary LPRTs (beamed in a detectable direction) with periods between ∼10 and 50 s within ∼95% of the surveyed region. Combined with the prevalence of LPRTs in the Galactic Plane, our results motivate further consideration of both White Dwarf-M Dwarf binary models and isolated magnetar models. We will continue to explore novel LPRT search strategies during real-time operations, such as triggered periodicity searches and additional targeted surveys.

", "doi": "10.1088/1538-3873/ae390e", "issn": "0004-6280", "publisher": "IOP Publishing", "publication": "Publications of the Astronomical Society of the Pacific", "publication_date": "2026-02", "series_number": "2", "volume": "138", "issue": "2", "pages": "024501" }, { "id": "authors:342me-1kb33", "collection": "authors", "collection_id": "342me-1kb33", "cite_using_url": "https://authors.library.caltech.edu/records/342me-1kb33", "type": "article", "title": "A Milliarcsecond Localization Associates FRB 20190417A with a Compact Persistent Radio Source and an Extreme Magnetoionic Environment", "author": [ { "family_name": "Moroianu", "given_name": "Alexandra M.", "orcid": "0000-0003-1936-9062" }, { "family_name": "Bhandari", "given_name": "Shivani", "orcid": "0000-0003-3460-506X" }, { "family_name": "Drout", "given_name": "Maria R.", "orcid": "0000-0001-7081-0082" }, { "family_name": "Hessels", "given_name": "Jason W. T.", "orcid": "0000-0003-2317-1446" }, { "family_name": "Hewitt", "given_name": "Dant\u00e9 M.", "orcid": "0000-0002-5794-2360" }, { "family_name": "Kirsten", "given_name": "Franz", "orcid": "0000-0001-6664-8668" }, { "family_name": "Marcote", "given_name": "Benito", "orcid": "0000-0001-9814-2354" }, { "family_name": "Pleunis", "given_name": "Ziggy", "orcid": "0000-0002-4795-697X" }, { "family_name": "Snelders", "given_name": "Mark P.", "orcid": "0000-0001-6170-2282" }, { "family_name": "Sridhar", "given_name": "Navin", "orcid": "0000-0002-5519-9550" }, { "family_name": "Bach", "given_name": "Uwe", "orcid": "0000-0002-7722-8412" }, { "family_name": "Bempong-Manful", "given_name": "Emmanuel K.", "orcid": "0000-0002-1727-1224" }, { "family_name": "Bezrukovs", "given_name": "Vladislavs", "orcid": "0000-0003-3655-2280" }, { "family_name": "Blaauw", "given_name": "Richard", "orcid": "0000-0003-1771-1012" }, { "family_name": "Bray", "given_name": "Justin D.", "orcid": "0000-0002-0963-0223" }, { "family_name": "Buttaccio", "given_name": "Salvatore", "orcid": "0000-0002-3341-466X" }, { "family_name": "Chatterjee", "given_name": "Shami", "orcid": "0000-0002-2878-1502" }, { "family_name": "Corongiu", "given_name": "Alessandro", "orcid": "0000-0002-5924-3141" }, { "family_name": "Feiler", "given_name": "Roman", "orcid": "0000-0002-9812-2078" }, { "family_name": "Gaensler", "given_name": "B. M.", "orcid": "0000-0002-3382-9558" }, { "family_name": "Gawro\u0144ski", "given_name": "Marcin P.", "orcid": "0000-0003-4056-4903" }, { "family_name": "Giroletti", "given_name": "Marcello", "orcid": "0000-0002-8657-8852" }, { "family_name": "Ibik", "given_name": "Adaeze L.", "orcid": "0000-0003-2405-2967" }, { "family_name": "Karuppusamy", "given_name": "Ramesh", "orcid": "0000-0002-5307-2919" }, { "family_name": "Lazda", "given_name": "Mattias", "orcid": "0000-0002-5857-4264" }, { "family_name": "Leung", "given_name": "Calvin", "orcid": "0000-0002-4209-7408" }, { "family_name": "Lindqvist", "given_name": "Michael", "orcid": "0000-0002-3669-0715" }, { "family_name": "Masui", "given_name": "Kiyoshi W.", "orcid": "0000-0002-4279-6946" }, { "family_name": "Michilli", "given_name": "Daniele", "orcid": "0000-0002-2551-7554" }, { "family_name": "Nimmo", "given_name": "Kenzie", "orcid": "0000-0003-0510-0740" }, { "family_name": "Ould-Boukattine", "given_name": "Omar S.", "orcid": "0000-0001-9381-8466" }, { "family_name": "Pandhi", "given_name": "Ayush", "orcid": "0000-0002-8897-1973" }, { "family_name": "Paragi", "given_name": "Zsolt", "orcid": "0000-0002-5195-335X" }, { "family_name": "Pearlman", "given_name": "Aaron B.", "orcid": "0000-0002-8912-0732" }, { "family_name": "Puchalska", "given_name": "Weronika", "orcid": "0000-0003-2422-6605" }, { "family_name": "Scholz", "given_name": "Paul", "orcid": "0000-0002-7374-7119" }, { "family_name": "Shin", "given_name": "Kaitlyn", "orcid": "0000-0002-6823-2073", "clpid": "Shin-Kaitlyn" }, { "family_name": "Sluman", "given_name": "Jurjen J." }, { "family_name": "Trudu", "given_name": "Matteo", "orcid": "0000-0002-1530-0474" }, { "family_name": "Williams-Baldwin", "given_name": "David", "orcid": "0000-0001-7361-0246" }, { "family_name": "Yang", "given_name": "Jun", "orcid": "0000-0002-2322-5232" } ], "abstract": "
\n

We report the milliarcsecond localization of a high (∼1379 pc cm−3) dispersion measure (DM) repeating fast radio burst (FRB), FRB 20190417A. Combining European VLBI Network detections of five repeat bursts, we confirm the FRB’s host to be a low-metallicity, star-forming dwarf galaxy at z = 0.12817, similar to the hosts of FRB 20121102A, FRB 20190520B, and FRB 20240114A. We also confirm that it is associated with a previously reported persistent radio source (PRS), which is compact on milliarcsecond scales. Visibility-domain model fitting constrains the transverse physical size of the PRS to <23 pc and yields an integrated flux density of 190 ± 40 μJy at 1.4 GHz. Though we do not find significant evidence for DM evolution, FRB 20190417A exhibits a time-variable rotation measure (RM) ranging between +3958 ± 11 rad m−2 and +5061 ± 24 rad m−2 over a 50-day period. We find no evidence for intervening galaxy clusters in the FRB’s line of sight and place a conservative lower limit on the rest-frame host DM contribution of 1228 pc cm−3 (90% confidence)—the largest known for any FRB so far. This system strengthens the emerging picture of a rare subclass of repeating FRBs with large and variable RMs, above-average host DMs, and luminous PRS counterparts in metal-poor dwarf galaxies. Our results suggest that these systems are the result of environmental selection, or a distinct engine for FRB emission.

\n
", "doi": "10.3847/2041-8213/ae28c7", "issn": "2041-8205", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal Letters", "publication_date": "2026-01-01", "series_number": "1", "volume": "996", "issue": "1", "pages": "L16" }, { "id": "authors:vm9bk-p8f73", "collection": "authors", "collection_id": "vm9bk-p8f73", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230717-55915200.21", "type": "article", "title": "Revealing the Dynamic Magnetoionic Environments of Repeating Fast Radio Burst Sources through Multiyear Polarimetric Monitoring with CHIME/FRB", "author": [ { "family_name": "Mckinven", "given_name": "R.", "orcid": "0000-0001-7348-6900", "clpid": "Mckinven-Ryan" }, { "family_name": "Gaensler", "given_name": "B. M.", "orcid": "0000-0002-3382-9558", "clpid": "Gaensler-Bryan-M" }, { "family_name": "Michilli", "given_name": "D.", "orcid": "0000-0002-2551-7554", "clpid": "Michilli-Daniele" }, { "family_name": "Masui", "given_name": "K.", "orcid": "0000-0002-4279-6946", "clpid": "Masui-Kiyoshi" }, { "family_name": "Kaspi", "given_name": "V. M.", "orcid": "0000-0001-9345-0307", "clpid": "Kaspi-Victoria-M" }, { "family_name": "Su", "given_name": "J.", "orcid": "0000-0003-0607-8194", "clpid": "Su-Jianing" }, { "family_name": "Bhardwaj", "given_name": "M.", "orcid": "0000-0002-3615-3514", "clpid": "Bhardwaj-Mohit" }, { "family_name": "Cassanelli", "given_name": "T.", "orcid": "0000-0003-2047-5276", "clpid": "Cassanelli-Tomas" }, { "family_name": "Chawla", "given_name": "P.", "orcid": "0000-0002-3426-7606", "clpid": "Chawla-Pragya" }, { "family_name": "Dong", "given_name": "F. (Adam)", "orcid": "0000-0003-4098-5222", "clpid": "Dong-Fengqiu-Adam" }, { "family_name": "Fonseca", "given_name": "E.", "orcid": "0000-0001-8384-5049", "clpid": "Fonseca-Emmanuel" }, { "family_name": "Leung", "given_name": "C.", "orcid": "0000-0002-4209-7408", "clpid": "Leung-Calvin" }, { "family_name": "Li", "given_name": "D. Z.", "orcid": "0000-0001-7931-0607", "clpid": "Li-Dongzi" }, { "family_name": "Ng", "given_name": "C.", "orcid": "0000-0002-3616-5160", "clpid": "Ng-Cherry" }, { "family_name": "Patel", "given_name": "C.", "orcid": "0000-0003-3367-1073", "clpid": "Patel-Chitrang" }, { "family_name": "Pearlman", "given_name": "A. B.", "orcid": "0000-0002-8912-0732", "clpid": "Pearlman-Aaron-B" }, { "family_name": "Petroff", "given_name": "E.", "orcid": "0000-0002-9822-8008", "clpid": "Petroff-Emily" }, { "family_name": "Pleunis", "given_name": "Z.", "orcid": "0000-0002-4795-697X", "clpid": "Pleunis-Ziggy" }, { "family_name": "Rafiei-Ravandi", "given_name": "M.", "orcid": "0000-0001-7694-6650", "clpid": "Rafiei-Ravandi-Masoud" }, { "family_name": "Rahman", "given_name": "M.", "orcid": "0000-0003-1842-6096", "clpid": "Rahman-Mubdi" }, { "family_name": "Sand", "given_name": "K. R.", "orcid": "0000-0003-3154-3676", "clpid": "Sand-Ketan-R" }, { "family_name": "Shin", "given_name": "K.", "orcid": "0000-0002-6823-2073", "clpid": "Shin-Kaitlyn" }, { "family_name": "Stairs", "given_name": "I. H.", "orcid": "0000-0001-9784-8670", "clpid": "Stairs-Ingrid-H" }, { "family_name": "Tendulkar", "given_name": "S.", "orcid": "0000-0003-2548-2926", "clpid": "Tendulkar-Shriharsh-P" } ], "abstract": "Fast radio bursts (FRBs) display a confounding variety of burst properties and host-galaxy associations. Repeating FRBs offer insight into the FRB population by enabling spectral, temporal, and polarimetric properties to be tracked over time. Here, we report on the polarized observations of 12 repeating sources using multiyear monitoring with the Canadian Hydrogen Intensity Mapping Experiment (CHIME) over 400\u2013800 MHz. We observe significant rotation measure (RM) variations from many sources in our sample, including RM changes of several hundred radians per square meter over month timescales from FRBs 20181119A, 20190303A, and 20190417A, and more modest RM variability (\u0394RM \u2272 few tens of radians per square meter) from FRBs 20181030A, 20190208A, 20190213B, and 20190117A over equivalent timescales. Several repeaters display a frequency-dependent degree of linear polarization that is consistent with depolarization via scattering. Combining our measurements of RM variations with equivalent constraints on DM variability, we estimate the average line-of-sight magnetic field strength in the local environment of each repeater. In general, repeating FRBs display RM variations that are more prevalent and/or extreme than those seen from radio pulsars in the Milky Way and the Magellanic Clouds, suggesting repeating FRBs and pulsars occupy distinct magnetoionic environments.", "doi": "10.3847/1538-4357/acd188", "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. 82" }, { "id": "authors:13qxb-ysr84", "collection": "authors", "collection_id": "13qxb-ysr84", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20211130-160124305", "type": "article", "title": "Scintillation Timescales of Bright FRBs Detected by CHIME/FRB", "author": [ { "family_name": "Schoen", "given_name": "Eve", "orcid": "0000-0001-8360-2098", "clpid": "Schoen-Eve" }, { "family_name": "Leung", "given_name": "Calvin", "orcid": "0000-0002-4209-7408", "clpid": "Leung-Calvin" }, { "family_name": "Masui", "given_name": "Kiyoshi", "orcid": "0000-0002-4279-6946", "clpid": "Masui-Kiyoshi" }, { "family_name": "Michilli", "given_name": "Daniele", "orcid": "0000-0002-2551-7554", "clpid": "Michilli-Daniele" }, { "family_name": "Chawla", "given_name": "Pragya", "orcid": "0000-0002-3426-7606", "clpid": "Chawla-Pragya" }, { "family_name": "Pearlman", "given_name": "Aaron B.", "orcid": "0000-0002-8912-0732", "clpid": "Pearlman-Aaron-B" }, { "family_name": "Shin", "given_name": "Kaitlyn", "orcid": "0000-0002-6823-2073", "clpid": "Shin-Kaitlyn" }, { "family_name": "Stock", "given_name": "Ashley", "orcid": "0000-0001-5351-824X", "clpid": "Stock-Ashley" }, { "literal": "CHIME/FRB Collaboration" } ], "abstract": "We describe a pipeline to measure scintillation in fast radio bursts (FRBs) detected by CHIME/FRB in the 400\u2013800 MHz band by analyzing the frequency structure of the FRB's spectrum. We use the pipeline to measure the characteristic frequency bandwidths of scintillation between 4\u2013100 kHz in 12 FRBs corresponding to timescales of \u223c2\u201340\u2009\u03bcs for 10 FRBs detected by CHIME/FRB. For the other two FRBs, we did not detect scintillation in the region our analysis is sensitive. We compared the measured scintillation timescales to the NE2001 predictions for the scintillation timescales from the Milky Way. We find a strong correlation to be an indication that in most instances, the observed scintillation of FRBs can be explained by the Milky Way.", "doi": "10.3847/2515-5172/ac3af9", "issn": "2515-5172", "publisher": "American Astronomical Society", "publication": "Research Notes of the AAS", "publication_date": "2021-11", "series_number": "11", "volume": "5", "issue": "11", "pages": "Art. No. 271" }, { "id": "authors:ya31j-40j77", "collection": "authors", "collection_id": "ya31j-40j77", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20211208-951324000", "type": "article", "title": "The Type II supernova SN 2020jfo in M 61, implications for progenitor system, and explosion dynamics", "author": [ { "family_name": "Sollerman", "given_name": "J.", "orcid": "0000-0003-1546-6615", "clpid": "Sollerman-Jesper" }, { "family_name": "Yang", "given_name": "S.", "orcid": "0000-0002-2898-6532", "clpid": "Yang-Sheng" }, { "family_name": "Schulze", "given_name": "S.", "orcid": "0000-0001-6797-1889", "clpid": "Schulze-Steve" }, { "family_name": "Strotjohann", "given_name": "N. L.", "orcid": "0000-0002-4667-6730", "clpid": "Strotjohann-Nora-Linn" }, { "family_name": "Jerkstrand", "given_name": "A.", "orcid": "0000-0001-8005-4030", "clpid": "Jerkstrand-Anders" }, { "family_name": "Van Dyk", "given_name": "S. D.", "orcid": "0000-0001-9038-9950", "clpid": "Van-Dyk-Schuyler-D" }, { "family_name": "Kool", "given_name": "E. C.", "orcid": "0000-0002-7252-3877", "clpid": "Kool-Erik-C" }, { "family_name": "Barbarino", "given_name": "C.", "orcid": "0000-0002-3821-6144", "clpid": "Barbarino-Cristina" }, { "family_name": "Brink", "given_name": "T. G.", "orcid": "0000-0001-5955-2502", "clpid": "Brink-Thomas-G" }, { "family_name": "Bruch", "given_name": "R.", "orcid": "0000-0001-8208-2473", "clpid": "Bruch-Rachel-J" }, { "family_name": "De", "given_name": "K.", "orcid": "0000-0002-8989-0542", "clpid": "De-Kishalay" }, { "family_name": "Filippenko", "given_name": "A. V.", "orcid": "0000-0003-3460-0103", "clpid": "Filippenko-Alexei-V" }, { "family_name": "Fremling", "given_name": "C.", "orcid": "0000-0002-4223-103X", "clpid": "Fremling-Christoffer" }, { "family_name": "Patra", "given_name": "K. C.", "orcid": "0000-0002-1092-6806", "clpid": "Patra-Kishore-Chandra" }, { "family_name": "Perley", "given_name": "D.", "orcid": "0000-0001-8472-1996", "clpid": "Perley-Daniel-A" }, { "family_name": "Yan", "given_name": "L.", "orcid": "0000-0003-1710-9339", "clpid": "Yan-Lin" }, { "family_name": "Yang", "given_name": "Y.", "orcid": "0000-0003-3078-2763", "clpid": "Yang-Yujin" }, { "family_name": "Andreoni", "given_name": "I.", "orcid": "0000-0002-8977-1498", "clpid": "Andreoni-Igor" }, { "family_name": "Campbell", "given_name": "R.", "orcid": "0000-0002-3289-5203", "clpid": "Campbell-Randall" }, { "family_name": "Coughlin", "given_name": "M.", "orcid": "0000-0002-8262-2924", "clpid": "Coughlin-Michael-W" }, { "family_name": "Kasliwal", "given_name": "M.", "orcid": "0000-0002-5619-4938", "clpid": "Kasliwal-M-M" }, { "family_name": "Kim", "given_name": "Y.-L.", "orcid": "0000-0002-1031-0796", "clpid": "Kim-Young-Lo" }, { "family_name": "Rigault", "given_name": "M.", "orcid": "0000-0002-8121-2560", "clpid": "Rigault-Mickael" }, { "family_name": "Shin", "given_name": "K.", "orcid": "0000-0002-6823-2073", "clpid": "Shin-Kaitlyn" }, { "family_name": "Tzanidakis", "given_name": "A.", "orcid": "0000-0003-0484-3331", "clpid": "Tzanidakis-Anastasios" }, { "family_name": "Ashley", "given_name": "M. C. B.", "orcid": "0000-0003-1412-2028", "clpid": "Ashley-Michael-C-B" }, { "family_name": "Moore", "given_name": "A. M.", "orcid": "0000-0002-2894-6936", "clpid": "Moore-Anna-Marie" }, { "family_name": "Travouillon", "given_name": "T.", "orcid": "0000-0001-9304-6718", "clpid": "Travouillon-Tony-D" } ], "abstract": "We present the discovery and extensive follow-up observations of SN 2020jfo, a Type IIP supernova (SN) in the nearby (14.5 Mpc) galaxy M 61. Optical light curves (LCs) and spectra from the Zwicky Transient Facility (ZTF), complemented with data from Swift/UVOT and near-infrared photometry is presented. These were used to model the 350-day duration bolometric light curve, which exhibits a relatively short (\u223c65 days) plateau. This implies a moderate ejecta mass (\u223c5 M_\u2299) at the time of explosion, whereas the deduced amount of ejected radioactive nickel is \u223c0.025 M_\u2299. An extensive series of spectroscopy is presented, including spectropolarimetric observations. The nebular spectra are dominated by H\u03b1, but also reveal emission lines from oxygen and calcium. Comparisons to synthetic nebular spectra indicate an initial progenitor mass of \u223c12 M_\u2299. We also note the presence of stable nickel in the nebular spectrum, and SN 2020jfo joins a small group of SNe that have inferred super-solar Ni/Fe ratios. Several years of prediscovery data were examined, but no signs of precursor activity were found. Pre-explosion Hubble Space Telescope imaging reveals a probable progenitor star, detected only in the reddest band (M_(F814W)\u2004\u2248\u2004\u22125.8) and it is fainter than expected for stars in the 10\u221215 M_\u2299 range. There is thus some tension between the LC analysis, the nebular spectral modeling, and the pre-explosion imaging. To compare and contrast, we present two additional core-collapse SNe monitored by the ZTF, which also have nebular H\u03b1-dominated spectra. This illustrates how the absence or presence of an interaction with circumstellar material (CSM) affect both the LCs and in particular the nebular spectra. Type II SN 2020amv has a LC powered by CSM interaction, in particular after \u223c40 days when the LC is bumpy and slowly evolving. The late-time spectra show strong H\u03b1 emission with a structure suggesting emission from a thin, dense shell. The evolution of the complex three-horn line profile is reminiscent of that observed for SN 1998S. Finally, SN 2020jfv has a poorly constrained early-time LC, but it is of interest because of the transition from a hydrogen-poor Type IIb to a Type IIn, where the nebular spectrum after the light-curve rebrightening is dominated by H\u03b1, although with an intermediate line width.", "doi": "10.1051/0004-6361/202141374", "issn": "0004-6361", "publisher": "EDP Sciences", "publication": "Astronomy and Astrophysics", "publication_date": "2021-11", "volume": "655", "pages": "Art. No. A105" }, { "id": "authors:z77ej-mm686", "collection": "authors", "collection_id": "z77ej-mm686", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210212-093111892", "type": "article", "title": "Metal Abundances across Cosmic Time (MACT) Survey. III \u2013 The relationship between stellar mass and star formation rate in extremely low-mass galaxies", "author": [ { "family_name": "Shin", "given_name": "Kaitlyn", "orcid": "0000-0002-6823-2073", "clpid": "Shin-Kaitlyn" }, { "family_name": "Ly", "given_name": "Chun", "orcid": "0000-0002-4245-2318", "clpid": "Ly-Chun" }, { "family_name": "Malkan", "given_name": "Matthew A.", "orcid": "0000-0001-6919-1237", "clpid": "Malkan-Matthew-A" }, { "family_name": "Malhotra", "given_name": "Sangeeta", "orcid": "0000-0002-9226-5350", "clpid": "Malhotra-Sangeeta" }, { "family_name": "de\u00a0los\u00a0Reyes", "given_name": "Mithi", "orcid": "0000-0002-4739-046X", "clpid": "de-los-Reyes-Mithi" }, { "family_name": "Rhoads", "given_name": "James E.", "orcid": "0000-0002-1501-454X", "clpid": "Rhoads-James-E" } ], "abstract": "Extragalactic studies have demonstrated that there is a moderately tight (\u22480.3 dex) relationship between galaxy stellar mass (M_\u22c6) and star formation rate (SFR) that holds for star-forming galaxies at M_\u22c6 \u223c 3 \u00d7 10\u2078\u201310\u00b9\u00b9 M_\u2299, i.e. the 'star formation main sequence'. However, it has yet to be determined whether such a relationship extends to even lower mass galaxies, particularly at intermediate or higher redshifts. We present new results using observations for 714 narrow-band H\u2009\u03b1-selected galaxies with stellar masses between 10\u2076 and 10\u00b9\u2070 M_\u2299 (average of 10^(8.2) M_\u2299) at z \u2248 0.07\u20130.5. These galaxies have sensitive ultraviolet (UV) to near-infrared photometric measurements and optical spectroscopy. The latter allows us to correct our H\u2009\u03b1 SFRs for dust attenuation using Balmer decrements. Our study reveals that: (1) for low-SFR galaxies, our H\u2009\u03b1 SFRs systematically underpredict compared to far-UV measurements, consistent with other studies; (2) at a given stellar mass (\u224810\u2078 M\u2299), log\u2009(specific SFR) evolves as A log\u2009(1 + z) with A = 5.26 \u00b1 0.75, and on average, specific SFR increases with decreasing stellar mass; (3) the SFR\u2013M\u22c6 relation holds for galaxies down to \u223c10\u2076 M_\u2299 (\u223c1.5 dex below previous studies), and over lookback times of up to 5 Gyr, follows a redshift-dependent relation of log\u2009(SFR) \u221d \u03b1 log\u2009(M_\u22c6/M_\u2299) + \u03b2 z with \u03b1 = 0.60 \u00b1 0.01 and \u03b2 = 1.86 \u00b1 0.07; and (4) the observed dispersion in the SFR\u2013M\u22c6 relation at low stellar masses is \u22480.3 dex. Accounting for survey selection effects using simulated galaxies, we estimate that the true dispersion is \u22480.5 dex.", "doi": "10.1093/mnras/staa3307", "issn": "0035-8711", "publisher": "Royal Astronomical Society", "publication": "Monthly Notices of the Royal Astronomical Society", "publication_date": "2021-02", "series_number": "2", "volume": "501", "issue": "2", "pages": "2231-2249" } ]