[
{
"id": "authors:mfhmf-w5a17",
"collection": "authors",
"collection_id": "mfhmf-w5a17",
"cite_using_url": "https://authors.library.caltech.edu/records/mfhmf-w5a17",
"type": "article",
"title": "A Luminous and Hot Infrared through X-Ray Transient at a 5 kpc Offset from a Dwarf Galaxy",
"author": [
{
"family_name": "Somalwar",
"given_name": "Jean J.",
"orcid": "0000-0001-8426-5732",
"clpid": "Somalwar-Jean-J"
},
{
"family_name": "Ravi",
"given_name": "Vikram",
"orcid": "0000-0002-7252-5485",
"clpid": "Ravi-Vikram"
},
{
"family_name": "Margutti",
"given_name": "Raffaella",
"orcid": "0000-0003-4768-7586"
},
{
"family_name": "Chornock",
"given_name": "Ryan",
"orcid": "0000-0002-7706-5668"
},
{
"family_name": "Natarajan",
"given_name": "Priyamvada",
"orcid": "0000-0002-5554-8896"
},
{
"family_name": "Lu",
"given_name": "Wenbin",
"orcid": "0000-0002-1568-7461"
},
{
"family_name": "Angus",
"given_name": "Charlotte",
"orcid": "0000-0002-4269-7999"
},
{
"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": "Nathan",
"given_name": "Edward",
"orcid": "0000-0002-9633-9193",
"clpid": "Nathan-Edward"
},
{
"family_name": "Nicholl",
"given_name": "Matt",
"orcid": "0000-0002-2555-3192"
},
{
"family_name": "Sharma",
"given_name": "Kritti",
"orcid": "0000-0002-4477-3625",
"clpid": "Sharma-Kritti"
},
{
"family_name": "Stein",
"given_name": "Robert",
"orcid": "0000-0003-2434-0387"
},
{
"family_name": "Verdi",
"given_name": "Frank",
"orcid": "0009-0005-3565-4164",
"clpid": "Verdi-Frank"
},
{
"family_name": "Yao",
"given_name": "Yuhan",
"orcid": "0000-0001-6747-8509"
},
{
"family_name": "Bellm",
"given_name": "Eric C.",
"orcid": "0000-0001-8018-5348"
},
{
"family_name": "Chen",
"given_name": "Tracy X.",
"orcid": "0000-0001-9152-6224",
"clpid": "Chen-Tracy-X"
},
{
"family_name": "Coughlin",
"given_name": "Michael W.",
"orcid": "0000-0002-8262-2924"
},
{
"family_name": "Hale",
"given_name": "David",
"clpid": "Hale-David"
},
{
"family_name": "Kasliwal",
"given_name": "Mansi M.",
"orcid": "0000-0002-5619-4938",
"clpid": "Kasliwal-M-M"
},
{
"family_name": "Laher",
"given_name": "Russ R.",
"orcid": "0000-0003-2451-5482",
"clpid": "Laher-R-R"
},
{
"family_name": "Riddle",
"given_name": "Reed",
"orcid": "0000-0002-0387-370X",
"clpid": "Riddle-Reed"
},
{
"family_name": "Sollerman",
"given_name": "Jesper",
"orcid": "0000-0003-1546-6615"
}
],
"abstract": "We are searching for hot, constant-color, offset optical flares in the Zwicky Transient Facility data stream that are >10″ from any galaxy in public imaging data from the PanSTARRS survey. Here, we present the first discovery from this search: AT 2024puz, a luminous multiwavelength transient offset by 5 kpc from a ∼108 M\u2299 galaxy at z = 0.356 with a low–moderate star formation rate (0.01 ± 0.003 M\u2299 yr−1). It produced luminous 1044.79±0.04 erg s−1 optical/UV emission that evolved on a ∼20 day timescale, as well as 1044.12±0.03 erg s−1 X-ray emission with a photon-index Γ = 1.73_(−0.09)^(+0.10). No associated radio or millimeter emission was detected. We show that the early time optical emission is likely powered by reprocessing of high-energy, accretion-powered radiation, with a possible contribution from a shock in a dense circumtransient medium. If the shock is dominant at early times, the circumtransient medium has a mass ∼0.1–1 M\u2299, a radius 1015 cm, and a density profile shallower than ∼r−1. A near-infrared excess appears at late-times and is suggestive of reprocessing within a wind or other circumtransient medium. The X-rays are most consistent with a central engine. We suggest that AT 2024puz may be associated with an accretion event onto a 50–105 M\u2299 black hole, where the lower masses are preferred based on the large projected offset from the host galaxy. AT2024puz exhibits properties similar to both luminous, fast, blue optical transients and tidal disruption events, but is intermediate between them in its energetics and evolution timescale. This highlights the need for broader exploration of the landscape of hot optical transients to trace their origins.
",
"doi": "10.3847/1538-4357/ae1501",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2025-12-20",
"series_number": "2",
"volume": "995",
"issue": "2",
"pages": "228"
},
{
"id": "authors:r494d-8jk37",
"collection": "authors",
"collection_id": "r494d-8jk37",
"cite_using_url": "https://authors.library.caltech.edu/records/r494d-8jk37",
"type": "article",
"title": "Prediscovery Activity of New Interstellar Object 3I/ATLAS: Rapid Brightening from 6 to 4 au",
"author": [
{
"family_name": "Ye \u53f6",
"given_name": "Quanzhi \u6cc9\u5fd7",
"orcid": "0000-0002-4838-7676"
},
{
"family_name": "Kelley",
"given_name": "Michael S. P.",
"orcid": "0000-0002-6702-7676"
},
{
"family_name": "Hsieh",
"given_name": "Henry H.",
"orcid": "0000-0001-7225-9271"
},
{
"family_name": "Bellm",
"given_name": "Eric C.",
"orcid": "0000-0001-8018-5348"
},
{
"family_name": "Chen",
"given_name": "Tracy X.",
"orcid": "0000-0001-9152-6224",
"clpid": "Chen-Tracy-X"
},
{
"family_name": "Dekany",
"given_name": "Richard",
"orcid": "0000-0002-5884-7867",
"clpid": "Dekany-Richard"
},
{
"family_name": "Drake",
"given_name": "Andrew",
"orcid": "0000-0003-0228-6594",
"clpid": "Drake-Andrew"
},
{
"family_name": "Groom",
"given_name": "Steven L.",
"orcid": "0000-0001-5668-3507",
"clpid": "Groom-Steven-L"
},
{
"family_name": "Helou",
"given_name": "George",
"orcid": "0000-0003-3367-3415",
"clpid": "Helou-G"
},
{
"family_name": "Kulkarni",
"given_name": "Shrinivas R.",
"orcid": "0000-0001-5390-8563",
"clpid": "Kulkarni-S-R"
},
{
"family_name": "Prince",
"given_name": "Thomas A.",
"orcid": "0000-0002-8850-3627",
"clpid": "Prince-T-A"
},
{
"family_name": "Riddle",
"given_name": "Reed",
"orcid": "0000-0002-0387-370X",
"clpid": "Riddle-Reed"
}
],
"abstract": "We report on the prediscovery observations and constraints of the new interstellar comet 3I/2025 N1 (ATLAS), made by the Zwicky Transient Facility, for the inbound leg of the comet out to a heliocentric distance of rh = 17 au, or approximately a year before its discovery. We find that 3I/ATLAS has been active inward of a heliocentric distance of at least rh = 6.5 au. The comet followed a brightening rate of ∝ r_h^(−3.8), which is significantly steeper than that of the only other known interstellar comet, 2I/Borisov, and is more consistent with dynamically old long-period comets and short-period comets in the solar system. By measuring the brightening of the dust coma, we estimate that 3I had a dust production rate of M_d \u0307 ∼ 5 kg s\u207b¹ in 2025 early May (rh ∼ 6 au), increasing to M_d \u0307 ∼ 5 kg s\u207b¹ toward 2025 mid-July (rh ∼ 4 au) assuming 100 μm dust grains, in line with the more recent Hubble Space Telescope measurement made at rh = 3.8 au. Comparison with the prediscovery photometry by the Transiting Exoplanet Survey Satellite suggested that 3I started producing constant dust outflow probably around rh ∼ 9 au, coinciding with the turn-on distance of CO2 ice. We also conduct a deep search of 3I/ATLAS with multiple nights of data taken in 2024, when the comet was at rh = 13–17 au, and conclude that the comet was no brighter than 2–5 mag above the coma or bare-nucleus lightcurves. This suggests that the comet did not exhibit strong outbursts during these periods, consistent with 2I/Borisov as well as most long-period solar system comets.
",
"doi": "10.3847/2041-8213/ae147b",
"issn": "2041-8205",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal Letters",
"publication_date": "2025-11-01",
"series_number": "1",
"volume": "993",
"issue": "1",
"pages": "L31"
},
{
"id": "authors:985q2-ndq40",
"collection": "authors",
"collection_id": "985q2-ndq40",
"cite_using_url": "https://authors.library.caltech.edu/records/985q2-ndq40",
"type": "article",
"title": "QZO: A Catalog of 5 Million Quasars from the Zwicky Transient Facility",
"author": [
{
"family_name": "Nakoneczny",
"given_name": "S. J.",
"orcid": "0000-0003-2130-7143",
"clpid": "Nakoneczny-Szymon-J"
},
{
"family_name": "Graham",
"given_name": "M. J.",
"orcid": "0000-0002-3168-0139",
"clpid": "Graham-M-J"
},
{
"family_name": "Stern",
"given_name": "D.",
"orcid": "0000-0003-2686-9241",
"clpid": "Stern-D"
},
{
"family_name": "Helou",
"given_name": "G.",
"orcid": "0000-0003-3367-3415",
"clpid": "Helou-G"
},
{
"family_name": "Djorgovski",
"given_name": "S. G.",
"orcid": "0000-0002-0603-3087",
"clpid": "Djorgovski-S-G"
},
{
"family_name": "Bellm",
"given_name": "E. C.",
"orcid": "0000-0001-8018-5348"
},
{
"family_name": "Chen",
"given_name": "T. X.",
"orcid": "0000-0001-9152-6224",
"clpid": "Chen-Tracy-X"
},
{
"family_name": "Dekany",
"given_name": "R.",
"orcid": "0000-0002-5884-7867",
"clpid": "Dekany-Richard"
},
{
"family_name": "Drake",
"given_name": "A.",
"orcid": "0000-0003-0228-6594",
"clpid": "Drake-Andrew"
},
{
"family_name": "Mahabal",
"given_name": "A. A.",
"orcid": "0000-0003-2242-0244",
"clpid": "Mahabal-A-A"
},
{
"family_name": "Prince",
"given_name": "T. A.",
"orcid": "0000-0002-8850-3627",
"clpid": "Prince-T-A"
},
{
"family_name": "Riddle",
"given_name": "R.",
"orcid": "0000-0002-0387-370X",
"clpid": "Riddle-Reed"
},
{
"family_name": "Rusholme",
"given_name": "B.",
"orcid": "0000-0001-7648-4142",
"clpid": "Rusholme-Benjamin"
},
{
"family_name": "Sravan",
"given_name": "N."
}
],
"abstract": "Machine learning methods are well established in the classification of quasars (QSOs). However, the advent of light-curve observations adds a great amount of complexity to the problem. Our goal is to use the Zwicky Transient Facility (ZTF) to create a catalog of QSOs. We process the ZTF DR20 light curves with a transformer artificial neural network and combine different surveys with extreme gradient boosting. Based on ZTF g-band and Wide-field Infrared Survey Explorer (WISE) observations, we find 4,849,574 objects classified as QSOs with confidence higher than 90% (QZO). We robustly classify objects fainter than the 5σ signal-to-noise ratio (SNR) limit at g = 20.8 by requiring g < nobs/80 + 20.375. For 33% of QZO objects, with available WISE data, we publish redshifts with estimated error Δz/(1 + z) = 0.14. We find that ZTF classification is superior to the Pan-STARRS static bands, and on par with WISE and Gaia measurements, but the light curves provide the most important features for QSO classification in the ZTF data set. Using ZTF g-band data with at least 100 observational epochs per light curve, we obtain a 97% F1 score for QSOs. We find that with 3 day median cadence, a survey time span of at least 900 days is required to achieve a 90% QSO F1 score. However, one can obtain the same score with a survey time span of 1800 days and the median cadence prolonged to 12 days.
",
"doi": "10.3847/1538-4357/adf4e4",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2025-10-10",
"series_number": "1",
"volume": "992",
"issue": "1",
"pages": "153"
},
{
"id": "authors:p89ah-3x949",
"collection": "authors",
"collection_id": "p89ah-3x949",
"cite_using_url": "https://authors.library.caltech.edu/records/p89ah-3x949",
"type": "article",
"title": "A Luminous Red Optical Flare and Hard X-Ray Emission in the Tidal Disruption Event AT 2024kmq",
"author": [
{
"family_name": "Ho",
"given_name": "Anna Y. Q.",
"orcid": "0000-0002-9017-3567"
},
{
"family_name": "Yao",
"given_name": "Yuhan",
"orcid": "0000-0001-6747-8509"
},
{
"family_name": "Matsumoto",
"given_name": "Tatsuya",
"orcid": "0000-0002-3809-0000"
},
{
"family_name": "Schroeder",
"given_name": "Genevieve",
"orcid": "0000-0001-9915-8147"
},
{
"family_name": "Coughlin",
"given_name": "Eric R.",
"orcid": "0000-0003-3765-6401"
},
{
"family_name": "Perley",
"given_name": "Daniel A.",
"orcid": "0000-0001-8472-1996"
},
{
"family_name": "Andreoni",
"given_name": "Igor",
"orcid": "0000-0002-8977-1498"
},
{
"family_name": "Bellm",
"given_name": "Eric C.",
"orcid": "0000-0001-8018-5348"
},
{
"family_name": "Chen",
"given_name": "Tracy X.",
"orcid": "0000-0001-9152-6224",
"clpid": "Chen-Tracy-X"
},
{
"family_name": "Chornock",
"given_name": "Ryan",
"orcid": "0000-0002-7706-5668"
},
{
"family_name": "Covarrubias",
"given_name": "Sofia",
"orcid": "0000-0003-1858-561X",
"clpid": "Covarrubias-Sofia"
},
{
"family_name": "Das",
"given_name": "Kaustav",
"orcid": "0000-0001-8372-997X",
"clpid": "Das-Kaustav"
},
{
"family_name": "Fremling",
"given_name": "Christoffer",
"orcid": "0000-0002-4223-103X",
"clpid": "Fremling-Christoffer"
},
{
"family_name": "Gilfanov",
"given_name": "Marat"
},
{
"family_name": "Hinds",
"given_name": "K. R.",
"orcid": "0000-0002-0129-806X"
},
{
"family_name": "Jarvis",
"given_name": "Dan",
"orcid": "0009-0004-3067-2227"
},
{
"family_name": "Kasliwal",
"given_name": "Mansi M.",
"orcid": "0000-0002-5619-4938",
"clpid": "Kasliwal-M-M"
},
{
"family_name": "Liu",
"given_name": "Chang",
"orcid": "0000-0002-7866-4531"
},
{
"family_name": "Lyman",
"given_name": "Joseph D.",
"orcid": "0000-0002-3464-0642"
},
{
"family_name": "Masci",
"given_name": "Frank J.",
"orcid": "0000-0002-8532-9395",
"clpid": "Masci-Frank-J"
},
{
"family_name": "Prince",
"given_name": "Thomas A.",
"orcid": "0000-0002-8850-3627",
"clpid": "Prince-T-A"
},
{
"family_name": "Ravi",
"given_name": "Vikram",
"orcid": "0000-0002-7252-5485",
"clpid": "Ravi-Vikram"
},
{
"family_name": "Rich",
"given_name": "R. Michael",
"orcid": "0000-0003-0427-8387"
},
{
"family_name": "Riddle",
"given_name": "Reed",
"orcid": "0000-0002-0387-370X",
"clpid": "Riddle-Reed"
},
{
"family_name": "Sevilla",
"given_name": "Cassie",
"orcid": "0009-0003-2780-704X"
},
{
"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": "Srinivasaragavan",
"given_name": "Gokul P.",
"orcid": "0000-0002-6428-2700"
},
{
"family_name": "Sunyaev",
"given_name": "Rashid"
},
{
"family_name": "Vail",
"given_name": "Jada L.",
"orcid": "0009-0000-4044-8799"
},
{
"family_name": "Wise",
"given_name": "Jacob L.",
"orcid": "0000-0003-0733-2916"
},
{
"family_name": "Yun",
"given_name": "Sol Bin",
"orcid": "0009-0000-4440-155X",
"clpid": "Yun-Sol-Bin"
}
],
"abstract": "\n
We present the optical discovery and multiwavelength follow-up observations of AT 2024kmq, a likely tidal disruption event (TDE) associated with a supermassive (MBH ∼ 108 M\u2299) black hole in a massive galaxy at z = 0.192. The optical light curve of AT 2024kmq exhibits two distinct peaks: an early fast (timescale 1 day) and luminous (M ≈ −20 mag) red peak, then a slower (timescale 1 month) blue peak with a higher optical luminosity (M ≈ −22 mag) and featureless optical spectra. The second component is similar to the spectroscopic class of “featureless TDEs” in the literature, and during this second component we detect highly variable, luminous (LX ≈ 1044 erg s−1), and hard (fν ∝ ν−1.5) X-ray emission. Luminous (1029 erg s−1 Hz−1 at 10 GHz) but unchanging radio emission likely arises from an underlying active galactic nucleus. The luminosity, timescale, and color of the early red optical peak can be explained by synchrotron emission, or alternatively by thermal emission from material at a large radius (R ≈ a few × 1015 cm). Possible physical origins for this early red component include an off-axis relativistic jet, and shocks from self-intersecting debris leading to the formation of the accretion disk. Late-time radio observations will help distinguish between the two possibilities.
\n
Although all Type II supernovae (SNe) originate from massive stars possessing a hydrogen-rich envelope, their light curve morphology is diverse, reflecting poorly characterised heterogeneity in the physical properties of their progenitor systems. Here, we present a detailed light curve analysis of a magnitude-limited sample of 639 Type II SNe from the Zwicky Transient Facility Bright Transient Survey. Using Gaussian processes, we systematically measure empirical light curve features (e.g. rise times, peak colours and luminosities) in a robust sampling-independent manner. We focus on rise times as they are highly sensitive to pre-explosion progenitor properties, especially the presence of a dense circumstellar medium (CSM) shed by the progenitor in the years immediately pre-explosion. By correlating our feature measurements with physical parameters from an extensive grid of STELLA hydrodynamical models with varying progenitor properties (CSM structure, M, R_(CSM) and M_(ZAMS)), we quantify the proportion of events with sufficient pre-explosion mass-loss to significantly alter the initial light curve (roughly M_(CSM) ≥ 10^(−2.5)M\u2299) in a highly complete sample of 377 spectroscopically classified Type II SNe. We find that 67 ± 6 per cent of observed SNe in our magnitude-limited sample show evidence for substantial CSM (MCSM ≥ 10^(−2.5)M\u2299) close to the progenitor (R_(CSM) < 10¹\u2075 cm) at the time of explosion. After applying a volumetric-correction, we find 36\u207a\u2075\u208b\u2087 per cent of all Type II SN progenitors possess substantial CSM within 10¹\u2075 cm at the time of explosion. This high fraction of progenitors with dense CSM, supported by photometric and spectroscopic evidence of previous SNe, reveals mass-loss rates significantly exceeding those measured in local group red supergiants or predicted by current theoretical models.
",
"doi": "10.1093/mnras/staf888",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2025-07",
"series_number": "1",
"volume": "541",
"issue": "1",
"pages": "135-165"
},
{
"id": "authors:hjgt4-w2z11",
"collection": "authors",
"collection_id": "hjgt4-w2z11",
"cite_using_url": "https://authors.library.caltech.edu/records/hjgt4-w2z11",
"type": "article",
"title": "A ZTF Search for Circumstellar Debris Transits in White Dwarfs: Six New Candidates, One with Gas Disk Emission, Identified in a Novel Metric Space",
"author": [
{
"family_name": "Bhattacharjee",
"given_name": "Soumyadeep",
"orcid": "0000-0003-2071-2956",
"clpid": "Bhattacharjee-Soumyadeep"
},
{
"family_name": "Vanderbosch",
"given_name": "Zachary P.",
"orcid": "0000-0002-0853-3464",
"clpid": "Vanderbosch-Zachary-P"
},
{
"family_name": "Hollands",
"given_name": "Mark A.",
"orcid": "0000-0003-0089-2080"
},
{
"family_name": "Tremblay",
"given_name": "Pier-Emmanuel",
"orcid": "0000-0001-9873-0121"
},
{
"family_name": "Xu \u8bb8",
"given_name": "Siyi \u5072\u827a",
"orcid": "0000-0002-8808-4282"
},
{
"family_name": "Guidry",
"given_name": "Joseph A.",
"orcid": "0000-0001-9632-7347"
},
{
"family_name": "Hermes",
"given_name": "J. J.",
"orcid": "0000-0001-5941-2286"
},
{
"family_name": "Caiazzo",
"given_name": "Ilaria",
"orcid": "0000-0002-4770-5388"
},
{
"family_name": "Rodriguez",
"given_name": "Antonio C.",
"orcid": "0000-0003-4189-9668",
"clpid": "Rodriguez-Antonio-C"
},
{
"family_name": "van Roestel",
"given_name": "Jan",
"orcid": "0000-0002-2626-2872"
},
{
"family_name": "El-Badry",
"given_name": "Kareem",
"orcid": "0000-0002-6871-1752",
"clpid": "El-Badry-Kareem"
},
{
"family_name": "Drake",
"given_name": "Andrew J.",
"orcid": "0000-0003-0228-6594",
"clpid": "Drake-Andrew-J"
},
{
"family_name": "Roulston",
"given_name": "Benjamin R.",
"orcid": "0000-0002-9453-7735"
},
{
"family_name": "Riddle",
"given_name": "Reed",
"orcid": "0000-0002-0387-370X",
"clpid": "Riddle-Reed"
},
{
"family_name": "Rusholme",
"given_name": "Ben",
"orcid": "0000-0001-7648-4142",
"clpid": "Rusholme-Benjamin"
},
{
"family_name": "Groom",
"given_name": "Steven L.",
"orcid": "0000-0001-5668-3507",
"clpid": "Groom-Steven-L"
},
{
"family_name": "Smith",
"given_name": "Roger",
"orcid": "0000-0001-7062-9726",
"clpid": "Smith-R-M"
},
{
"family_name": "Toloza",
"given_name": "Odette",
"orcid": "0000-0002-2398-719X"
}
],
"abstract": "\n
White dwarfs (WDs) showing transits from orbiting planetary debris provide significant insights into the structure and dynamics of debris disks, which are eventually accreted to produce metal pollution. This is a rare class of objects with only eight published systems. In this work, we perform a systematic search for such systems within 500 pc in the Gaia-eDR3 catalog of WDs using the light curves from the Zwicky Transient Facility (ZTF) and present six new candidates. Our selection process targets the top 1% most photometrically variable sources identified using a combined variability metric from ZTF and Gaia eDR3 photometry, boosted by a metric space we define using von Neumann statistics and Pearson-Skew as a novel discovery tool to identify these systems. This is followed by optical spectroscopic observations of visually selected variables to confirm metal pollution. Four of the six systems show long-timescale photometric variability spanning several months to years, resulting either from long-term evolution of transit activity or dust and debris clouds at wide orbits. Among them, WD J1013–0427 shows an indication of reddening during the long-duration dip. Interpreting this as dust extinction makes it the first system to indicate an abundance of dust grains with radius \u22720.3 μm in the occulting material. The same object also shows metal emission lines that map an optically thick eccentric gas disk orbiting within the star’s Roche limit. For each candidate, we infer the abundances of the photospheric metals and estimate accretion rates. We show that transiting debris systems tend to have higher inferred accretion rates compared to the general population of metal-polluted WDs. Growing the number of these systems will further illuminate such comparative properties in the near future. Separately, we also serendipitously discovered an AM Canis Venaticorum showing a very long-duration outburst—only the fourth such system to be known.
\n
\n
Tidal disruption events (TDEs) occur when a star enters the tidal radius of a supermassive black hole. If the star only grazes the tidal radius, a fraction of the stellar mass will be accreted in a partial TDE (pTDE). The remainder can continue orbiting and may be redisrupted at pericenter, causing a repeating pTDE. pTDEs may be as or more common than full TDEs, yet few are known. In this work, we present the discovery of the first repeating pTDE from a systematically selected sample, AT 2020vdq. AT 2020vdq was originally identified as an optically and radio-flaring TDE. Around 947 days after its discovery, it rebrightened dramatically in the optical. The optical flare was remarkably fast and luminous given its black hole mass compared to previous TDEs. It was accompanied by extremely broad (∼0.1c) optical/UV spectral features and faint X-ray emission (LX ∼ 3 × 1041 erg s−1), but no new radio-emitting component. Based on the transient optical/UV spectral features and the broadband lightcurve, we show that AT 2020vdq is a repeating pTDE. We then use it to constrain TDE models; in particular, we favor a star originally in a very tight binary system that is tidally broken apart by the Hills mechanism. We also constrain the repeating pTDE rate to be 10−6–10−5 yr−1 galaxy−1, with uncertainties dominated by the unknown distribution of pTDE repeat timescales. In the Hills framework, this means the binary fraction in the galactic nucleus is of the order of a few percent.
\n
Tidal disruption events (TDEs) that are spatially offset from the nuclei of their host galaxies offer a new probe of massive black hole (MBH) wanderers, binaries, triples, and recoiling MBHs. Here we present AT2024tvd, the first off-nuclear TDE identified through optical sky surveys. High-resolution imaging with the Hubble Space Telescope shows that AT2024tvd is 0914 ± 0010 offset from the apparent center of its host galaxy, corresponding to a projected distance of 0.808 ± 0.009 kpc at z = 0.045. Chandra and Very Large Array observations support the same conclusion for the TDE's X-ray and radio emission. AT2024tvd exhibits typical properties of nuclear TDEs, including a persistent hot UV/optical component that peaks at Lbb ∼ 6 × 1043 erg s−1, broad hydrogen lines in its optical spectra, and delayed brightening of luminous (LX,peak ∼ 3 × 1043 erg s−1), highly variable soft X-ray emission. The MBH mass of AT2024tvd is 106±1 M\u2299, at least 10 times lower than its host galaxy's central black hole mass (\u2273108 M\u2299). The MBH in AT2024tvd has two possible origins: a wandering MBH from the lower-mass galaxy in a minor merger during the dynamical friction phase or a recoiling MBH ejected by triple interactions. Combining AT2024tvd with two previously known off-nuclear TDEs discovered in X-rays (3XMM J2150 and EP240222a), which likely involve intermediate-mass black holes in satellite galaxies, we find that the parent galaxies of all three events are very massive (∼1010.9 M\u2299). This result aligns with expectations from cosmological simulations that the number of offset MBHs scales linearly with the host halo mass.
",
"doi": "10.3847/2041-8213/add7de",
"issn": "2041-8205",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal Letters",
"publication_date": "2025-06-01",
"series_number": "2",
"volume": "985",
"issue": "2",
"pages": "L48"
},
{
"id": "authors:yn9nt-yns25",
"collection": "authors",
"collection_id": "yn9nt-yns25",
"cite_using_url": "https://authors.library.caltech.edu/records/yn9nt-yns25",
"type": "article",
"title": "ZTF-observed late-time signals of pre-ZTF transients",
"author": [
{
"family_name": "Terwel",
"given_name": "Jacco H.",
"orcid": "0000-0001-9834-3439"
},
{
"family_name": "Maguire",
"given_name": "Kate",
"orcid": "0000-0002-9770-3508"
},
{
"family_name": "Sollerman",
"given_name": "Jesper",
"orcid": "0000-0003-1546-6615"
},
{
"family_name": "Wiseman",
"given_name": "Phil",
"orcid": "0000-0002-3073-1512"
},
{
"family_name": "Chen",
"given_name": "Tracy X.",
"orcid": "0000-0001-9152-6224",
"clpid": "Chen-Tracy-X"
},
{
"family_name": "Graham",
"given_name": "Matthew J.",
"orcid": "0000-0002-3168-0139",
"clpid": "Graham-M-J"
},
{
"family_name": "Laher",
"given_name": "Russ R.",
"orcid": "0000-0003-2451-5482",
"clpid": "Laher-R-R"
},
{
"family_name": "Riddle",
"given_name": "Reed",
"orcid": "0000-0002-0387-370X",
"clpid": "Riddle-Reed"
},
{
"family_name": "Sravan",
"given_name": "Niharika"
}
],
"abstract": "With large-scale surveys such as the Zwicky Transient Facility (ZTF), it has become possible to obtain a well-sampled light curve spanning the full length of the survey for any discovery within the survey footprint. Similarly, any transient within the footprint that was first detected before the start of the survey will likely have a large number of post-transient observations, making such transients excellent targets to search for the presence of late-time signals, particularly those due to interaction with circumstellar material (CSM). We searched for late-time signals in a sample of 7718 transients, mainly supernovae (SNe), that were first detected during the 10 years before the start of ZTF, aiming to find objects showing signs of late-time interaction with CSM. We found one candidate whose late-time signal is best explained by late-time CSM interaction, with the signal being around 300 days after transient discovery. A thin, distant shell containing \u22725 M\u2299 of material could explain the recovered signal. We also found five objects whose late-time signal is best explained by faint nuclear transients occurring in host nuclei close to the pre-ZTF transient locations. Finally, we found two objects where it is difficult to determine whether the signal is from a nuclear transient or due to late-time CSM interaction occurring over 5 years after the SN. This study demonstrates the ability of large-scale surveys to find faint transient signals for a variety of objects and uncover a population of previously unknown sources. However, the large number of non-detections shows that strong late-time CSM interaction occurring years after the SN explosion is extremely rare.
",
"doi": "10.1051/0004-6361/202452198",
"issn": "0004-6361",
"publisher": "EDP Sciences",
"publication": "Astronomy and Astrophysics",
"publication_date": "2025-05",
"volume": "697",
"pages": "A143"
},
{
"id": "authors:msjpj-n0609",
"collection": "authors",
"collection_id": "msjpj-n0609",
"cite_using_url": "https://authors.library.caltech.edu/records/msjpj-n0609",
"type": "article",
"title": "Sample of hydrogen-rich superluminous supernovae from the Zwicky Transient Facility",
"author": [
{
"family_name": "Pessi",
"given_name": "P. J.",
"orcid": "0000-0002-8041-8559"
},
{
"family_name": "Lunnan",
"given_name": "R.",
"orcid": "0000-0001-9454-4639"
},
{
"family_name": "Sollerman",
"given_name": "J.",
"orcid": "0000-0003-1546-6615"
},
{
"family_name": "Schulze",
"given_name": "S.",
"orcid": "0000-0001-6797-1889"
},
{
"family_name": "Gkini",
"given_name": "A.",
"orcid": "0009-0000-9383-2305"
},
{
"family_name": "Gangopadhyay",
"given_name": "A.",
"orcid": "0000-0002-3884-5637"
},
{
"family_name": "Yan",
"given_name": "L.",
"orcid": "0000-0003-1710-9339",
"clpid": "Yan-Lin"
},
{
"family_name": "Gal-Yam",
"given_name": "A.",
"orcid": "0000-0002-3653-5598"
},
{
"family_name": "Perley",
"given_name": "D. A.",
"orcid": "0000-0001-8472-1996"
},
{
"family_name": "Chen",
"given_name": "T.-W.",
"orcid": "0000-0002-1066-6098"
},
{
"family_name": "Hinds",
"given_name": "K. R.",
"orcid": "0000-0002-0129-806X"
},
{
"family_name": "Brennan",
"given_name": "S. J.",
"orcid": "0000-0003-1325-6235"
},
{
"family_name": "Hu",
"given_name": "Y.",
"orcid": "0000-0002-9744-3910"
},
{
"family_name": "Singh",
"given_name": "A.",
"orcid": "0000-0003-2091-622X"
},
{
"family_name": "Andreoni",
"given_name": "I.",
"orcid": "0000-0002-8977-1498"
},
{
"family_name": "Cook",
"given_name": "D. O.",
"orcid": "0000-0002-6877-7655",
"clpid": "Cook-David-O"
},
{
"family_name": "Fremling",
"given_name": "C.",
"orcid": "0000-0002-4223-103X",
"clpid": "Fremling-Christoffer"
},
{
"family_name": "Ho",
"given_name": "A. Y. Q.",
"orcid": "0000-0002-9017-3567"
},
{
"family_name": "Sharma",
"given_name": "Y.",
"orcid": "0000-0003-4531-1745",
"clpid": "Sharma-Yashvi"
},
{
"family_name": "van Velzen",
"given_name": "S."
},
{
"family_name": "Kangas",
"given_name": "T."
},
{
"family_name": "Wold",
"given_name": "A.",
"orcid": "0000-0002-9998-6732",
"clpid": "Wold-Avery"
},
{
"family_name": "Bellm",
"given_name": "E. C.",
"orcid": "0000-0001-8018-5348"
},
{
"family_name": "Bloom",
"given_name": "J. S.",
"orcid": "0000-0002-7777-216X"
},
{
"family_name": "Graham",
"given_name": "M. J.",
"orcid": "0000-0002-3168-0139",
"clpid": "Graham-M-J"
},
{
"family_name": "Kasliwal",
"given_name": "M. M.",
"orcid": "0000-0002-5619-4938",
"clpid": "Kasliwal-M-M"
},
{
"family_name": "Kulkarni",
"given_name": "S. R.",
"orcid": "0000-0001-5390-8563",
"clpid": "Kulkarni-S-R"
},
{
"family_name": "Riddle",
"given_name": "R.",
"orcid": "0000-0002-0387-370X",
"clpid": "Riddle-Reed"
},
{
"family_name": "Rusholme",
"given_name": "B.",
"orcid": "0000-0001-7648-4142",
"clpid": "Rusholme-Benjamin"
}
],
"abstract": "Context. Hydrogen-rich superluminous supernovae (SLSNe II) are rare. The exact mechanism producing their extreme light curve peaks is not understood. Analysis of single events and small samples suggest that circumstellar material (CSM) interaction is the main mechanism responsible for the observed features. However, other mechanisms cannot be discarded. Large sample analysis can provide clarification. Aims. We aim to characterize the light curves of a sample of 107 SLSNe II to provide valuable information that can be used to validate theoretical models. Methods. We analyzed the gri light curves of SLSNe II obtained through ZTF. We studied the peak absolute magnitudes and characteristic timescales. When possible, we computed the g\u2005−\u2005r colors and pseudo-bolometric light curves, and estimated lower limits for their total radiated energy. We also studied the luminosity distribution of our sample and estimated the fraction that would be observable by the LSST. Finally, we compared our sample to other H-rich SNe and to H-poor SLSNe I. Results. SLSNe II are heterogeneous. Their median peak absolute magnitude is ∼\u2005−\u200520.3 mag in optical bands. Their rise can take from ∼two weeks to over three months, and their decline times range from ∼twenty days to over a year. We found no significant correlations between peak magnitude and timescales. SLSNe II tend to show fainter peaks, longer declines, and redder colors than SLSNe I. Conclusions. We present the largest sample of SLSN II light curves to date, comprising 107 events. Their diversity could be explained by different CSM morphologies, although theoretical analysis is needed to explore alternative scenarios. Other luminous transients, such as active galactic nuclei, tidal disruption events or SNe Ia-CSM, can easily become contaminants. Thus, good multiwavelength light curve coverage becomes paramount. LSST could miss ∼30% of the ZTF events in its gri band footprint.
",
"doi": "10.1051/0004-6361/202452014",
"issn": "0004-6361",
"publisher": "EDP Sciences",
"publication": "Astronomy and Astrophysics",
"publication_date": "2025-03",
"volume": "695",
"pages": "A142"
},
{
"id": "authors:dcsf2-1sg15",
"collection": "authors",
"collection_id": "dcsf2-1sg15",
"cite_using_url": "https://authors.library.caltech.edu/records/dcsf2-1sg15",
"type": "article",
"title": "The luminous, slow-rising orphan afterglow AT2019pim as a candidate moderately relativistic outflow",
"author": [
{
"family_name": "Perley",
"given_name": "Daniel A",
"orcid": "0000-0001-8472-1996"
},
{
"family_name": "Ho",
"given_name": "Anna Y Q",
"orcid": "0000-0002-9017-3567"
},
{
"family_name": "Fausnaugh",
"given_name": "Michael",
"orcid": "0000-0002-9113-7162"
},
{
"family_name": "Lamb",
"given_name": "Gavin P",
"orcid": "0000-0001-5169-4143"
},
{
"family_name": "Kasliwal",
"given_name": "Mansi M",
"orcid": "0000-0002-5619-4938",
"clpid": "Kasliwal-M-M"
},
{
"family_name": "Ahumada",
"given_name": "Tomas",
"orcid": "0000-0002-2184-6430",
"clpid": "Ahumada-Tom\u00e1s"
},
{
"family_name": "Anand",
"given_name": "Shreya",
"orcid": "0000-0003-3768-7515",
"clpid": "Anand-Shreya"
},
{
"family_name": "Andreoni",
"given_name": "Igor",
"orcid": "0000-0002-8977-1498"
},
{
"family_name": "Bellm",
"given_name": "Eric",
"orcid": "0000-0001-8018-5348"
},
{
"family_name": "Bhalerao",
"given_name": "Varun",
"orcid": "0000-0002-6112-7609"
},
{
"family_name": "Bolin",
"given_name": "Bryce",
"orcid": "0000-0002-4950-6323"
},
{
"family_name": "Brink",
"given_name": "Thomas G"
},
{
"family_name": "Burns",
"given_name": "Eric"
},
{
"family_name": "Cenko",
"given_name": "S Bradley",
"orcid": "0000-0003-1673-970X"
},
{
"family_name": "Corsi",
"given_name": "Alessandra",
"orcid": "0000-0001-8104-3536"
},
{
"family_name": "Filippenko",
"given_name": "Alexei V",
"orcid": "0000-0003-3460-0103"
},
{
"family_name": "Frederiks",
"given_name": "Dmitry",
"orcid": "0000-0002-1153-6340"
},
{
"family_name": "Goldstein",
"given_name": "Adam"
},
{
"family_name": "Hamburg",
"given_name": "Rachel"
},
{
"family_name": "Jayaraman",
"given_name": "Rahul"
},
{
"family_name": "Jonker",
"given_name": "Peter G",
"orcid": "0000-0001-5679-0695"
},
{
"family_name": "Kool",
"given_name": "Erik C",
"orcid": "0000-0002-7252-3877"
},
{
"family_name": "Kulkarni",
"given_name": "Shrinivas R",
"orcid": "0000-0001-5390-8563",
"clpid": "Kulkarni-S-R"
},
{
"family_name": "Kumar",
"given_name": "Harsh",
"orcid": "0000-0003-0871-4641"
},
{
"family_name": "Laher",
"given_name": "Russ",
"orcid": "0000-0003-2451-5482",
"clpid": "Laher-R-R"
},
{
"family_name": "Levan",
"given_name": "Andrew",
"orcid": "0000-0001-7821-9369"
},
{
"family_name": "Lysenko",
"given_name": "Alexandra"
},
{
"family_name": "Perley",
"given_name": "Richard A",
"orcid": "0000-0001-7097-8360"
},
{
"family_name": "Ricker",
"given_name": "George R",
"orcid": "0000-0003-2058-6662"
},
{
"family_name": "Riddle",
"given_name": "Reed",
"orcid": "0000-0002-0387-370X",
"clpid": "Riddle-Reed"
},
{
"family_name": "Ridnaia",
"given_name": "Anna",
"orcid": "0000-0001-9477-5437"
},
{
"family_name": "Rusholme",
"given_name": "Ben",
"orcid": "0000-0001-7648-4142",
"clpid": "Rusholme-Benjamin"
},
{
"family_name": "Smith",
"given_name": "Roger",
"orcid": "0000-0001-7062-9726",
"clpid": "Smith-R-M"
},
{
"family_name": "Svinkin",
"given_name": "Dmitry",
"orcid": "0000-0002-2208-2196"
},
{
"family_name": "Ulanov",
"given_name": "Mikhail",
"orcid": "0000-0002-0076-5228"
},
{
"family_name": "Vanderspek",
"given_name": "Roland",
"orcid": "0000-0001-6763-6562"
},
{
"family_name": "Waratkar",
"given_name": "Gaurav",
"orcid": "0000-0003-3630-9440"
},
{
"family_name": "Yao",
"given_name": "Yuhan"
}
],
"abstract": "Classical gamma-ray bursts (GRBs) have two distinct emission episodes: prompt emission from ultrarelativistic ejecta and afterglow from shocked circumstellar material. While both components are extremely luminous in known GRBs, a variety of scenarios predict the existence of luminous afterglow emission with little or no associated high-energy prompt emission. We present AT 2019pim, the first spectroscopically confirmed afterglow with no observed high-energy emission to be identified. Serendipitously discovered during follow-up observations of a gravitational-wave trigger and located in a contemporaneous TESS sector, it is hallmarked by a fast-rising ($t \\approx 2$ h), luminous ($M_{\\rm UV,peak} \\approx -24.4$ mag) optical transient with accompanying luminous X-ray and radio emission. No gamma-ray emission consistent with the time and location of the transient was detected by Fermi-GBM or by Konus, placing constraining limits on an accompanying GRB. We investigate several independent observational aspects of the afterglow in the context of constraints on relativistic motion and find all of them are consistent with an initial Lorentz factor of $\\Gamma _0 \\approx$ 10–30 for the on-axis material, significantly lower than in any well-observed GRB and consistent with the theoretically predicted 'dirty fireball' scenario in which the high-energy prompt emission is stifled by pair production. However, we cannot rule out a structured jet model in which only the line-of-sight material was ejected at low-$\\Gamma$, off-axis from a classical high-$\\Gamma$ jet core, and an on-axis GRB with below-average gamma-ray efficiency also remains a possibility. This event represents a milestone in orphan afterglow searches, demonstrating that luminous optical afterglows lacking detected GRB counterparts can be identified and spectroscopically confirmed in real time.
",
"doi": "10.1093/mnras/staf125",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2025-03",
"series_number": "3",
"volume": "537",
"issue": "3",
"pages": "1-18"
},
{
"id": "authors:qz82n-mwq18",
"collection": "authors",
"collection_id": "qz82n-mwq18",
"cite_using_url": "https://authors.library.caltech.edu/records/qz82n-mwq18",
"type": "article",
"title": "ZTF SN Ia DR2: Overview",
"author": [
{
"family_name": "Rigault",
"given_name": "M.",
"orcid": "0000-0002-8121-2560"
},
{
"family_name": "Smith",
"given_name": "M.",
"orcid": "0000-0002-3321-1432"
},
{
"family_name": "Goobar",
"given_name": "A.",
"orcid": "0000-0002-4163-4996"
},
{
"family_name": "Maguire",
"given_name": "K.",
"orcid": "0000-0002-9770-3508"
},
{
"family_name": "Dimitriadis",
"given_name": "G.",
"orcid": "0000-0001-9494-179X"
},
{
"family_name": "Johansson",
"given_name": "J.",
"orcid": "0000-0001-5975-290X"
},
{
"family_name": "Nordin",
"given_name": "J.",
"orcid": "0000-0001-8342-6274"
},
{
"family_name": "Burgaz",
"given_name": "U.",
"orcid": "0000-0003-0126-3999"
},
{
"family_name": "Dhawan",
"given_name": "S.",
"orcid": "0000-0002-2376-6979"
},
{
"family_name": "Sollerman",
"given_name": "J.",
"orcid": "0000-0003-1546-6615"
},
{
"family_name": "Regnault",
"given_name": "N.",
"orcid": "0000-0001-7029-7901"
},
{
"family_name": "Kowalski",
"given_name": "M.",
"orcid": "0000-0001-8594-8666"
},
{
"family_name": "Nugent",
"given_name": "P.",
"orcid": "0000-0002-3389-0586"
},
{
"family_name": "Andreoni",
"given_name": "I.",
"orcid": "0000-0002-8977-1498"
},
{
"family_name": "Amenouche",
"given_name": "M.",
"orcid": "0009-0006-7454-3579"
},
{
"family_name": "Aubert",
"given_name": "M."
},
{
"family_name": "Barjou-Delayre",
"given_name": "C."
},
{
"family_name": "Bautista",
"given_name": "J.",
"orcid": "0000-0002-9885-3989"
},
{
"family_name": "Bellm",
"given_name": "E.",
"orcid": "0000-0001-8018-5348"
},
{
"family_name": "Betoule",
"given_name": "M.",
"orcid": "0000-0003-0804-836X"
},
{
"family_name": "Bloom",
"given_name": "J. S.",
"orcid": "0000-0002-7777-216X"
},
{
"family_name": "Carreres",
"given_name": "B.",
"orcid": "0000-0002-7234-844X"
},
{
"family_name": "Chen",
"given_name": "T. X.",
"orcid": "0000-0001-9152-6224",
"clpid": "Chen-Tracy-X"
},
{
"family_name": "Copin",
"given_name": "Y.",
"orcid": "0000-0002-5317-7518"
},
{
"family_name": "Deckers",
"given_name": "M.",
"orcid": "0000-0001-8857-9843"
},
{
"family_name": "de Jaeger",
"given_name": "T.",
"orcid": "0000-0001-6069-1139"
},
{
"family_name": "Feinstein",
"given_name": "F.",
"orcid": "0000-0001-5548-3466"
},
{
"family_name": "Fouchez",
"given_name": "D.",
"orcid": "0000-0002-7496-3796"
},
{
"family_name": "Fremling",
"given_name": "C.",
"orcid": "0000-0002-4223-103X",
"clpid": "Fremling-Christoffer"
},
{
"family_name": "Galbany",
"given_name": "L.",
"orcid": "0000-0002-1296-6887"
},
{
"family_name": "Ginolin",
"given_name": "M.",
"orcid": "0009-0004-5311-9301"
},
{
"family_name": "Graham",
"given_name": "M.",
"orcid": "0000-0002-3168-0139",
"clpid": "Graham-M-J"
},
{
"family_name": "Groom",
"given_name": "S. L.",
"orcid": "0000-0001-5668-3507",
"clpid": "Groom-Steven-L"
},
{
"family_name": "Harvey",
"given_name": "L.",
"orcid": "0000-0003-3393-9383"
},
{
"family_name": "Kasliwal",
"given_name": "M. M.",
"orcid": "0000-0002-5619-4938",
"clpid": "Kasliwal-M-M"
},
{
"family_name": "Kenworthy",
"given_name": "W. D.",
"orcid": "0000-0002-5153-5983"
},
{
"family_name": "Kim",
"given_name": "Y.-L.",
"orcid": "0000-0002-1031-0796"
},
{
"family_name": "Kuhn",
"given_name": "D.",
"orcid": "0009-0005-8110-397X"
},
{
"family_name": "Kulkarni",
"given_name": "S. R.",
"orcid": "0000-0001-5390-8563",
"clpid": "Kulkarni-S-R"
},
{
"family_name": "Lacroix",
"given_name": "L.",
"orcid": "0000-0003-0629-5746"
},
{
"family_name": "Laher",
"given_name": "R. R.",
"orcid": "0000-0003-2451-5482",
"clpid": "Laher-R-R"
},
{
"family_name": "Masci",
"given_name": "F. J.",
"orcid": "0000-0002-8532-9395",
"clpid": "Masci-Frank-J"
},
{
"family_name": "M\u00fcller-Bravo",
"given_name": "T. E.",
"orcid": "0000-0003-3939-7167"
},
{
"family_name": "Miller",
"given_name": "A.",
"orcid": "0000-0001-9515-478X"
},
{
"family_name": "Osman",
"given_name": "M.",
"orcid": "0009-0000-6101-6725"
},
{
"family_name": "Perley",
"given_name": "D.",
"orcid": "0000-0001-8472-1996"
},
{
"family_name": "Popovic",
"given_name": "B.",
"orcid": "0000-0002-8012-6978"
},
{
"family_name": "Purdum",
"given_name": "J.",
"orcid": "0000-0003-1227-3738",
"clpid": "Purdum-Josiah"
},
{
"family_name": "Qin",
"given_name": "Y.-J.",
"orcid": "0000-0003-3658-6026",
"clpid": "Qin-Yu-Jing"
},
{
"family_name": "Racine",
"given_name": "B.",
"orcid": "0000-0001-8861-3052"
},
{
"family_name": "Reusch",
"given_name": "S.",
"orcid": "0000-0002-7788-628X"
},
{
"family_name": "Riddle",
"given_name": "R.",
"orcid": "0000-0002-0387-370X",
"clpid": "Riddle-Reed"
},
{
"family_name": "Rosnet",
"given_name": "P.",
"orcid": "0000-0002-6099-7565"
},
{
"family_name": "Rosselli",
"given_name": "D.",
"orcid": "0000-0001-6839-1421"
},
{
"family_name": "Ruppin",
"given_name": "F.",
"orcid": "0000-0002-0955-8954"
},
{
"family_name": "Senzel",
"given_name": "R.",
"orcid": "0009-0002-0243-8199"
},
{
"family_name": "Rusholme",
"given_name": "B.",
"orcid": "0000-0001-7648-4142",
"clpid": "Rusholme-Benjamin"
},
{
"family_name": "Schweyer",
"given_name": "T.",
"orcid": "0000-0001-8948-3456"
},
{
"family_name": "Terwel",
"given_name": "J. H.",
"orcid": "0000-0001-9834-3439"
},
{
"family_name": "Townsend",
"given_name": "A.",
"orcid": "0000-0001-6343-3362"
},
{
"family_name": "Tzanidakis",
"given_name": "A.",
"orcid": "0000-0003-0484-3331"
},
{
"family_name": "Wold",
"given_name": "A.",
"orcid": "0000-0002-9998-6732",
"clpid": "Wold-Avery"
},
{
"family_name": "Yan",
"given_name": "L.",
"orcid": "0000-0003-1710-9339",
"clpid": "Yan-Lin"
}
],
"abstract": "We present the first homogeneous release of several thousand spectroscopically classified type Ia supernovae (SNe Ia) with spectroscopic redshifts. This release, named “DR2”, contains 3628 nearby (z\u2004<\u20040.3) SNe Ia discovered, followed, and classified by the Zwicky Transient Facility survey between March 2018 and December 2020. Of these, 3000 have good-to-excellent sampling and 2667 pass standard cosmology light curve quality cuts. This release is thus the largest SN Ia release to date, increasing by an order of magnitude the number of well-characterized low-redshift objects. With DR2, we also provide a volume-limited (z\u2004<\u20040.06) sample of nearly a thousand SNe Ia. With such a large, homogeneous, and well-controlled dataset, we are studying key current questions on SN cosmology, such as the linearity SNe Ia standardization, the SN and host dependencies, the diversity of the SN Ia population, and the accuracy of current light curve modeling. These, and more, are studied in detail in a series of articles associated with this release. Alongside the SN Ia parameters, we publish our forced-photometry gri-band light curves, 5138 spectra, local and global host properties, observing logs, and a Python tool to facilitate the use and access of these data. The photometric accuracy of DR2 is not yet suited for cosmological parameter inference, which will follow as the “DR2.5” release. We nonetheless demonstrate that our Hubble diagram of several thousands of SNe Ia has a typical 0.15 mag scatter.
",
"doi": "10.1051/0004-6361/202450388",
"issn": "0004-6361",
"publisher": "EDP Sciences",
"publication": "Astronomy and Astrophysics",
"publication_date": "2025-02",
"volume": "694",
"pages": "A1"
},
{
"id": "authors:ck40a-pj869",
"collection": "authors",
"collection_id": "ck40a-pj869",
"cite_using_url": "https://authors.library.caltech.edu/records/ck40a-pj869",
"type": "article",
"title": "Candidate strongly lensed type Ia supernovae in the Zwicky Transient Facility archive",
"author": [
{
"family_name": "Townsend",
"given_name": "A.",
"orcid": "0000-0001-6343-3362"
},
{
"family_name": "Nordin",
"given_name": "J.",
"orcid": "0000-0001-8342-6274"
},
{
"family_name": "Sagu\u00e9s Carracedo",
"given_name": "A.",
"orcid": "0000-0002-3498-2167"
},
{
"family_name": "Kowalski",
"given_name": "M.",
"orcid": "0000-0001-8594-8666"
},
{
"family_name": "Arendse",
"given_name": "N.",
"orcid": "0000-0001-5409-6480"
},
{
"family_name": "Dhawan",
"given_name": "S.",
"orcid": "0000-0002-2376-6979"
},
{
"family_name": "Goobar",
"given_name": "A.",
"orcid": "0000-0002-4163-4996"
},
{
"family_name": "Johansson",
"given_name": "J.",
"orcid": "0000-0001-5975-290X"
},
{
"family_name": "M\u00f6rtsell",
"given_name": "E.",
"orcid": "0000-0002-8380-6143"
},
{
"family_name": "Schulze",
"given_name": "S.",
"orcid": "0000-0001-6797-1889"
},
{
"family_name": "Andreoni",
"given_name": "I.",
"orcid": "0000-0002-8977-1498"
},
{
"family_name": "Fern\u00e1ndez",
"given_name": "E."
},
{
"family_name": "Kim",
"given_name": "A. G.",
"orcid": "0000-0001-6315-8743"
},
{
"family_name": "Nugent",
"given_name": "P. E.",
"orcid": "0000-0002-3389-0586"
},
{
"family_name": "Prada",
"given_name": "F.",
"orcid": "0000-0001-7145-8674"
},
{
"family_name": "Rigault",
"given_name": "M.",
"orcid": "0000-0002-8121-2560"
},
{
"family_name": "Sarin",
"given_name": "N.",
"orcid": "0000-0003-2700-1030"
},
{
"family_name": "Sharma",
"given_name": "D."
},
{
"family_name": "Bellm",
"given_name": "E. C.",
"orcid": "0000-0001-8018-5348"
},
{
"family_name": "Coughlin",
"given_name": "M. W.",
"orcid": "0000-0002-8262-2924"
},
{
"family_name": "Dekany",
"given_name": "R.",
"orcid": "0000-0002-5884-7867",
"clpid": "Dekany-Richard"
},
{
"family_name": "Groom",
"given_name": "S. L.",
"orcid": "0000-0001-5668-3507",
"clpid": "Groom-Steven-L"
},
{
"family_name": "Lacroix",
"given_name": "L.",
"orcid": "0000-0003-0629-5746"
},
{
"family_name": "Laher",
"given_name": "Russ R.",
"orcid": "0000-0003-2451-5482",
"clpid": "Laher-R-R"
},
{
"family_name": "Riddle",
"given_name": "R.",
"orcid": "0000-0002-0387-370X",
"clpid": "Riddle-Reed"
},
{
"family_name": "Aguilar",
"given_name": "J.",
"orcid": "0000-0003-0822-452X"
},
{
"family_name": "Ahlen",
"given_name": "S.",
"orcid": "0000-0001-6098-7247"
},
{
"family_name": "Bailey",
"given_name": "S.",
"orcid": "0000-0003-4162-6619"
},
{
"family_name": "Brooks",
"given_name": "D."
},
{
"family_name": "Claybaugh",
"given_name": "T.",
"orcid": "0000-0002-5024-6987"
},
{
"family_name": "de la Macorra",
"given_name": "A.",
"orcid": "0000-0002-1769-1640"
},
{
"family_name": "Dey",
"given_name": "A.",
"orcid": "0000-0002-4928-4003"
},
{
"family_name": "Dey",
"given_name": "B.",
"orcid": "0000-0002-5665-7912"
},
{
"family_name": "Doel",
"given_name": "P."
},
{
"family_name": "Fanning",
"given_name": "K.",
"orcid": "0000-0003-2371-3356"
},
{
"family_name": "Forero-Romero",
"given_name": "J. E.",
"orcid": "0000-0002-2890-3725"
},
{
"family_name": "Gazta\u00f1aga",
"given_name": "E.",
"orcid": "0000-0001-9632-0815"
},
{
"family_name": "Gontcho A Gontcho",
"given_name": "S.",
"orcid": "0000-0003-3142-233X"
},
{
"family_name": "Honscheid",
"given_name": "K."
},
{
"family_name": "Howlett",
"given_name": "C.",
"orcid": "0000-0002-1081-9410"
},
{
"family_name": "Kisner",
"given_name": "T.",
"orcid": "0000-0003-3510-7134"
},
{
"family_name": "Kremin",
"given_name": "A.",
"orcid": "0000-0001-6356-7424"
},
{
"family_name": "Lambert",
"given_name": "A.",
"orcid": "0009-0003-5658-2601"
},
{
"family_name": "Landriau",
"given_name": "M.",
"orcid": "0000-0003-1838-8528"
},
{
"family_name": "Le Guillou",
"given_name": "L.",
"orcid": "0000-0001-7178-8868"
},
{
"family_name": "Levi",
"given_name": "M. E.",
"orcid": "0000-0003-1887-1018"
},
{
"family_name": "Manera",
"given_name": "M.",
"orcid": "0000-0003-4962-8934"
},
{
"family_name": "Meisner",
"given_name": "A.",
"orcid": "0000-0002-1125-7384"
},
{
"family_name": "Miquel",
"given_name": "R."
},
{
"family_name": "Moustakas",
"given_name": "J.",
"orcid": "0000-0002-2733-4559"
},
{
"family_name": "Mueller",
"given_name": "E."
},
{
"family_name": "Myers",
"given_name": "A. D."
},
{
"family_name": "Nie",
"given_name": "J.",
"orcid": "0000-0001-6590-8122"
},
{
"family_name": "Palanque-Delabrouille",
"given_name": "N.",
"orcid": "0000-0003-3188-784X"
},
{
"family_name": "Poppett",
"given_name": "C."
},
{
"family_name": "Rezaie",
"given_name": "M.",
"orcid": "0000-0001-5589-7116"
},
{
"family_name": "Rossi",
"given_name": "G."
},
{
"family_name": "Sanchez",
"given_name": "E.",
"orcid": "0000-0002-9646-8198"
},
{
"family_name": "Schlegel",
"given_name": "D.",
"orcid": "0000-0002-5042-5088"
},
{
"family_name": "Schubnell",
"given_name": "M."
},
{
"family_name": "Seo",
"given_name": "H.",
"orcid": "0000-0002-6588-3508"
},
{
"family_name": "Sprayberry",
"given_name": "D."
},
{
"family_name": "Tarl\u00e9",
"given_name": "G.",
"orcid": "0000-0003-1704-0781"
},
{
"family_name": "Zou",
"given_name": "H.",
"orcid": "0000-0002-6684-3997"
}
],
"abstract": "Context. Gravitationally lensed type Ia supernovae (glSNe Ia) are unique astronomical tools that can be used to study cosmological parameters, distributions of dark matter, the astrophysics of the supernovae, and the intervening lensing galaxies themselves. A small number of highly magnified glSNe Ia have been discovered by ground-based telescopes such as the Zwicky Transient Facility (ZTF), but simulations predict that a fainter, undetected population may also exist.
\nAims. We present a systematic search for glSNe Ia in the ZTF archive of alerts distributed from June 1 2019 to September 1 2022.
\nMethods. Using the AMPEL platform, we developed a pipeline that distinguishes candidate glSNe Ia from other variable sources. Initial cuts were applied to the ZTF alert photometry (with constraints on the peak absolute magnitude and the distance to a catalogue-matched galaxy, as examples) before forced photometry was obtained for the remaining candidates. Additional cuts were applied to refine the candidates based on their light curve colours, lens galaxy colours, and the resulting parameters from fits to the SALT2 SN Ia template. The candidates were also cross-matched with the DESI spectroscopic catalogue.
\nResults. Seven transients were identified that passed all the cuts and had an associated galaxy DESI redshift, which we present as glSN Ia candidates. Although superluminous supernovae (SLSNe) cannot be fully rejected as contaminants, two events, ZTF19abpjicm and ZTF22aahmovu, are significantly different from typical SLSNe and their light curves can be modelled as two-image glSN Ia systems. From this two-image modelling, we estimate time delays of 22\u2005±\u20053 and 34\u2005±\u20051 days for the two events, respectively, which suggests that we have uncovered a population of glSNe Ia with longer time delays.
\nConclusions. The pipeline is efficient and sensitive enough to parse full alert streams. It is currently being applied to the live ZTF alert stream to identify and follow-up future candidates while active. This pipeline could be the foundation for glSNe Ia searches in future surveys, such as the Rubin Observatory Legacy Survey of Space and Time.
",
"doi": "10.1051/0004-6361/202451082",
"issn": "0004-6361",
"publisher": "EDP Sciences",
"publication": "Astronomy and Astrophysics",
"publication_date": "2025-02",
"volume": "694",
"pages": "A146"
},
{
"id": "authors:5gj69-yyr83",
"collection": "authors",
"collection_id": "5gj69-yyr83",
"cite_using_url": "https://authors.library.caltech.edu/records/5gj69-yyr83",
"type": "article",
"title": "A Link Between White Dwarf Pulsars and Polars: Multiwavelength Observations of the 9.36-minute Period Variable Gaia22ayj",
"author": [
{
"family_name": "Rodriguez",
"given_name": "Antonio C.",
"orcid": "0000-0003-4189-9668",
"clpid": "Rodriguez-Antonio-C"
},
{
"family_name": "El-Badry",
"given_name": "Kareem",
"orcid": "0000-0002-6871-1752",
"clpid": "El-Badry-Kareem"
},
{
"family_name": "Hakala",
"given_name": "Pasi",
"orcid": "0009-0003-6437-0369"
},
{
"family_name": "Rodr\u00edguez-Gil",
"given_name": "Pablo",
"orcid": "0000-0002-4717-5102"
},
{
"family_name": "Bao",
"given_name": "Tong",
"orcid": "0000-0002-5082-5049"
},
{
"family_name": "Galiullin",
"given_name": "Ilkham",
"orcid": "0000-0001-5778-2355"
},
{
"family_name": "Kurlander",
"given_name": "Jacob A.",
"orcid": "0009-0005-5452-0671"
},
{
"family_name": "Law",
"given_name": "Casey J.",
"orcid": "0000-0002-4119-9963",
"clpid": "Law-Casey-J"
},
{
"family_name": "Pelisoli",
"given_name": "Ingrid",
"orcid": "0000-0003-4615-6556"
},
{
"family_name": "Schreiber",
"given_name": "Matthias R.",
"orcid": "0000-0003-3903-8009"
},
{
"family_name": "Burdge",
"given_name": "Kevin",
"orcid": "0000-0002-7226-836X"
},
{
"family_name": "Caiazzo",
"given_name": "Ilaria",
"orcid": "0000-0002-4770-5388"
},
{
"family_name": "Roestel",
"given_name": "Jan van",
"orcid": "0000-0002-2626-2872"
},
{
"family_name": "Szkody",
"given_name": "Paula",
"orcid": "0000-0003-4373-7777"
},
{
"family_name": "Drake",
"given_name": "Andrew J.",
"clpid": "Drake-Andrew-J"
},
{
"family_name": "Buckley",
"given_name": "David A. H.",
"orcid": "0000-0002-7004-9956"
},
{
"family_name": "Potter",
"given_name": "Stephen B.",
"orcid": "0000-0002-5956-2249"
},
{
"family_name": "Gaensicke",
"given_name": "Boris",
"orcid": "0000-0002-2761-3005"
},
{
"family_name": "Mori",
"given_name": "Kaya",
"orcid": "0000-0002-9709-5389"
},
{
"family_name": "Bellm",
"given_name": "Eric C.",
"orcid": "0000-0001-8018-5348"
},
{
"family_name": "Kulkarni",
"given_name": "Shrinivas R.",
"orcid": "0000-0001-5390-8563",
"clpid": "Kulkarni-S-R"
},
{
"family_name": "Prince",
"given_name": "Thomas A.",
"orcid": "0000-0002-8850-3627",
"clpid": "Prince-T-A"
},
{
"family_name": "Graham",
"given_name": "Matthew",
"orcid": "0000-0002-3168-0139",
"clpid": "Graham-M-J"
},
{
"family_name": "Kasliwal",
"given_name": "Mansi M.",
"orcid": "0000-0002-5619-4938",
"clpid": "Kasliwal-M-M"
},
{
"family_name": "Rose",
"given_name": "Sam",
"orcid": "0000-0003-4725-4481",
"clpid": "Rose-Sam"
},
{
"family_name": "Sharma",
"given_name": "Yashvi",
"orcid": "0000-0003-4531-1745",
"clpid": "Sharma-Yashvi"
},
{
"family_name": "Ahumada",
"given_name": "Tom\u00e1s",
"orcid": "0000-0002-2184-6430",
"clpid": "Ahumada-Tom\u00e1s"
},
{
"family_name": "Anand",
"given_name": "Shreya",
"orcid": "0000-0003-3768-7515",
"clpid": "Anand-Shreya"
},
{
"family_name": "Viitanen",
"given_name": "Akke",
"orcid": "0000-0001-9383-786X"
},
{
"family_name": "Wold",
"given_name": "Avery",
"orcid": "0000-0002-9998-6732",
"clpid": "Wold-Avery"
},
{
"family_name": "Chen",
"given_name": "Tracy X.",
"orcid": "0000-0001-9152-6224",
"clpid": "Chen-Tracy-X"
},
{
"family_name": "Riddle",
"given_name": "Reed",
"orcid": "0000-0002-0387-370X",
"clpid": "Riddle-Reed"
},
{
"family_name": "Smith",
"given_name": "Roger",
"orcid": "0000-0001-7062-9726",
"clpid": "Smith-R-M"
}
],
"abstract": "White dwarfs (WDs) are the most abundant compact objects, and recent surveys have suggested that over a third of WDs in accreting binaries host a strong (B \u2273 1 MG) magnetic field. However, the origin and evolution of WD magnetism remain under debate. Two WD pulsars, AR Sco and J191213.72–441045.1 (J1912), have been found, which are non-accreting binaries hosting rapidly spinning (1.97 minutes and 5.30 minutes, respectively) magnetic WDs. The WD in AR Sco is slowing down on a P/P\u02d9≈5.6×10\u2076 yr timescale. It is believed they will eventually become polars, accreting systems in which a magnetic WD (B ≈ 10−240 MG) accretes from a Roche lobe-filling donor spinning in sync with the orbit (\u227378 minutes). Here, we present multiwavelength data and analysis of Gaia22ayj, which outbursted in 2022 March. We find that Gaia22ayj is a magnetic accreting WD that is rapidly spinning down (P/P\u02d9=6.1_(−0.2)^(+0.3)×10\u2076 yr) like WD pulsars, but shows clear evidence of accretion, like polars. Strong linear polarization (40%) is detected in Gaia22ayj; such high levels have only been seen in the WD pulsar AR Sco and demonstrate the WD is magnetic. High speed photometry reveals a 9.36 minutes period accompanying a high amplitude (∼2 mag) modulation. We associate this with a WD spin or spin–orbit beat period, not an orbital period as was previously suggested. Fast (60 s) optical spectroscopy reveals a broad \"hump,\" reminiscent of cyclotron emission in polars, between 4000 and 8000 Å. We find an X-ray luminosity of L_X=2.7_(−0.8)^(+6.2)×10³²ergs\u207b¹ in the 0.3–8 keV energy range, while two very large array radio campaigns resulted in a non-detection with a Fr < 15.8 μJy 3σ upper limit. The shared properties of both WD pulsars and polars suggest that Gaia22ayj is a missing link between the two classes of magnetic WD binaries.
",
"doi": "10.1088/1538-3873/adb0f1",
"issn": "0004-6280",
"publisher": "IOP Publishing",
"publication": "Publications of the Astronomical Society of the Pacific",
"publication_date": "2025-02",
"series_number": "2",
"volume": "137",
"issue": "2",
"pages": "024202"
},
{
"id": "authors:0smha-tck25",
"collection": "authors",
"collection_id": "0smha-tck25",
"cite_using_url": "https://authors.library.caltech.edu/records/0smha-tck25",
"type": "article",
"title": "Cataclysmic Variables and AM CVn Binaries in SRG/eROSITA + Gaia: Volume Limited Samples, X-Ray Luminosity Functions, and Space Densities",
"author": [
{
"family_name": "Rodriguez",
"given_name": "Antonio C.",
"orcid": "0000-0003-4189-9668",
"clpid": "Rodriguez-Antonio-C"
},
{
"family_name": "El-Badry",
"given_name": "Kareem",
"orcid": "0000-0002-6871-1752",
"clpid": "El-Badry-Kareem"
},
{
"family_name": "Suleimanov",
"given_name": "Valery",
"orcid": "0000-0003-3733-7267"
},
{
"family_name": "Pala",
"given_name": "Anna F.",
"orcid": "0000-0001-7069-7403"
},
{
"family_name": "Kulkarni",
"given_name": "Shrinivas R.",
"orcid": "0000-0001-5390-8563",
"clpid": "Kulkarni-S-R"
},
{
"family_name": "Gaensicke",
"given_name": "Boris",
"orcid": "0000-0002-2761-3005"
},
{
"family_name": "Mori",
"given_name": "Kaya",
"orcid": "0000-0002-9709-5389"
},
{
"family_name": "Rich",
"given_name": "R. Michael",
"orcid": "0000-0003-0427-8387"
},
{
"family_name": "Sarkar",
"given_name": "Arnab",
"orcid": "0000-0002-1455-2784"
},
{
"family_name": "Bao",
"given_name": "Tong",
"orcid": "0000-0002-5082-5049"
},
{
"family_name": "de Oliveira",
"given_name": "Raimundo Lopes",
"orcid": "0000-0002-6211-7226"
},
{
"family_name": "Ramsay",
"given_name": "Gavin",
"orcid": "0000-0001-8722-9710"
},
{
"family_name": "Szkody",
"given_name": "Paula",
"orcid": "0000-0003-4373-7777"
},
{
"family_name": "Graham",
"given_name": "Matthew",
"orcid": "0000-0002-3168-0139",
"clpid": "Graham-M-J"
},
{
"family_name": "Prince",
"given_name": "Thomas A.",
"orcid": "0000-0002-8850-3627",
"clpid": "Prince-T-A"
},
{
"family_name": "Caiazzo",
"given_name": "Ilaria",
"orcid": "0000-0002-4770-5388",
"clpid": "Caiazzo-Ilaria"
},
{
"family_name": "Vanderbosch",
"given_name": "Zachary P.",
"orcid": "0000-0002-0853-3464",
"clpid": "Vanderbosch-Zachary-P"
},
{
"family_name": "Roestel",
"given_name": "Jan van",
"orcid": "0000-0002-2626-2872"
},
{
"family_name": "Das",
"given_name": "Kaustav K.",
"orcid": "0000-0001-8372-997X",
"clpid": "Das-Kaustav-K"
},
{
"family_name": "Qin",
"given_name": "Yu-Jing",
"orcid": "0000-0003-3658-6026",
"clpid": "Qin-Yu-Jing"
},
{
"family_name": "Kasliwal",
"given_name": "Mansi M.",
"orcid": "0000-0002-5619-4938",
"clpid": "Kasliwal-M-M"
},
{
"family_name": "Wold",
"given_name": "Avery",
"orcid": "0000-0002-9998-6732",
"clpid": "Wold-Avery"
},
{
"family_name": "Groom",
"given_name": "Steven L.",
"orcid": "0000-0001-5668-3507",
"clpid": "Groom-Steven-L"
},
{
"family_name": "Reiley",
"given_name": "Daniel",
"clpid": "Reiley-Daniel"
},
{
"family_name": "Riddle",
"given_name": "Reed",
"orcid": "0000-0002-0387-370X",
"clpid": "Riddle-Reed"
}
],
"abstract": "We present volume-limited samples of cataclysmic variables (CVs) and AM CVn binaries jointly selected from SRG/eROSITA eRASS1 and Gaia DR3 using an X-ray + optical color–color diagram (the “X-ray Main Sequence”). This tool identifies all CV subtypes, including magnetic and low-accretion rate systems, in contrast to most previous surveys. We find 23 CVs, 3 of which are AM CVns, out to 150 pc in the Western Galactic Hemisphere. Our 150 pc sample is spectroscopically verified and complete down to LX = 1.3 × 1029 erg s−1 in the 0.2–2.3 keV band, and we also present CV candidates out to 300 pc and 1000 pc. We discovered two previously unknown systems in our 150 pc sample: the third nearest AM CVn and a magnetic period bouncer. We find the mean LX of CVs to be \u3008LX\u3009 ≈ 4.6 × 1030 erg s−1, in contrast to previous surveys which yielded \u3008LX\u3009 ∼ 1031−1032 erg s−1. We construct X-ray luminosity functions that, for the first time, flatten out at LX ∼ 1030 erg s−1. We infer average number, mass, and luminosity densities of ρN,CV = (3.7 ± 0.7) × 10−6pc−3, ρM = (5.0 ± 1.0) ×10−\u2075 M \u2299−1, and ρLX = (2.3 ± 0.4) × 10²\u2076 erg s−1M\u2299−1, respectively, in the solar neighborhood. Our uniform selection method also allows us to place meaningful estimates on the space density of AM CVns, ρN,AM CVn = (5.5 ± 3.7) × 10−7 pc−3. Magnetic CVs and period bouncers make up 35% and 25% of our sample, respectively. This work, through a novel discovery technique, shows that the observed number densities of CVs and AM CVns, as well as the fraction of period bouncers, are still in tension with population synthesis estimates.
",
"doi": "10.1088/1538-3873/ada185",
"issn": "0004-6280",
"publisher": "IOP Publishing",
"publication": "Publications of the Astronomical Society of the Pacific",
"publication_date": "2025-01",
"series_number": "1",
"volume": "137",
"issue": "1",
"pages": "014201"
},
{
"id": "authors:701th-2p095",
"collection": "authors",
"collection_id": "701th-2p095",
"cite_using_url": "https://authors.library.caltech.edu/records/701th-2p095",
"type": "article",
"title": "Haro 5-2: A New Pre-main-sequence Quadruple Stellar System",
"author": [
{
"family_name": "Reipurth",
"given_name": "Bo",
"orcid": "0000-0001-8174-1932"
},
{
"family_name": "Brice\u00f1o",
"given_name": "C.",
"orcid": "0000-0001-7124-4094"
},
{
"family_name": "Geballe",
"given_name": "T. R.",
"orcid": "0000-0003-2824-3875"
},
{
"family_name": "Baranec",
"given_name": "C.",
"orcid": "0000-0002-1917-9157"
},
{
"family_name": "Mikkola",
"given_name": "S.",
"orcid": "0000-0003-1448-8767"
},
{
"family_name": "Cody",
"given_name": "A. M.",
"orcid": "0000-0002-3656-6706"
},
{
"family_name": "Connelley",
"given_name": "M. S.",
"orcid": "0000-0002-8293-1428"
},
{
"family_name": "Flores",
"given_name": "C.",
"orcid": "0000-0002-8591-472X"
},
{
"family_name": "Skiff",
"given_name": "B. A.",
"orcid": "0000-0001-5306-6220"
},
{
"family_name": "Armstrong",
"given_name": "J. D."
},
{
"family_name": "Law",
"given_name": "N. M.",
"orcid": "0000-0001-9380-6457"
},
{
"family_name": "Riddle",
"given_name": "R.",
"orcid": "0000-0002-0387-370X",
"clpid": "Riddle-Reed"
}
],
"abstract": "We have discovered that the Hα emission-line star Haro 5-2, located in the 3–6 Myr old Ori OB1b association, is a young quadruple system. The system has a 2+2 configuration, with an outer separation of 2.″6 and with resolved subarcsecond inner binary components. The brightest component, Aa, dominates the A-binary; it is a weak-line T Tauri star with spectral type M2.5±1. The two stars of the B component are equally bright at J, but the Bb star is much redder. Optical spectroscopy of the combined B pair indicates a rich emission-line spectrum with a M3±1 spectral type. The spectrum is highly variable and switches back and forth between a classical and a weak-line T Tauri star. In the near-IR, the spectrum shows Paschen β and Brackett γ in emission, indicative of active accretion. A significant mid-IR excess reveals the presence of circumstellar or circumbinary material in the system. Most multiple systems are likely formed during the protostellar phase, involving flybys of neighboring stars followed by an inspiraling phase driven by accretion from circumbinary material and leading to compact subsystems. However, Haro 5-2 stands out among young 2+2 quadruples, as the two inner binaries are unusually wide relative to the separation of the A and B pair, allowing future studies of the individual components. Assuming the components are coeval, the system could potentially allow stringent tests of pre-main-sequence evolutionary models.
",
"doi": "10.3847/1538-3881/ad5956",
"issn": "0004-6256",
"publisher": "American Astronomical Society",
"publication": "Astronomical Journal",
"publication_date": "2024-10-01",
"series_number": "4",
"volume": "168",
"issue": "4",
"pages": "143"
},
{
"id": "authors:tfkwb-wk493",
"collection": "authors",
"collection_id": "tfkwb-wk493",
"cite_using_url": "https://authors.library.caltech.edu/records/tfkwb-wk493",
"type": "article",
"title": "Searching for new cataclysmic variables in the Chandra Source Catalog",
"author": [
{
"family_name": "Galiullin",
"given_name": "Ilkham",
"orcid": "0000-0001-5778-2355"
},
{
"family_name": "Rodriguez",
"given_name": "Antonio C.",
"orcid": "0000-0003-4189-9668",
"clpid": "Rodriguez-Antonio-C"
},
{
"family_name": "El-Badry",
"given_name": "Kareem",
"orcid": "0000-0002-6871-1752",
"clpid": "El-Badry-Kareem"
},
{
"family_name": "Szkody",
"given_name": "Paula",
"orcid": "0000-0003-4373-7777"
},
{
"family_name": "Anand",
"given_name": "Abhijeet",
"orcid": "0000-0003-2923-1585"
},
{
"family_name": "van Roestel",
"given_name": "Jan",
"orcid": "0000-0002-2626-2872"
},
{
"family_name": "Sibgatullin",
"given_name": "Askar",
"orcid": "0009-0007-8224-316X"
},
{
"family_name": "Dodon",
"given_name": "Vladislav",
"orcid": "0009-0003-7483-0090"
},
{
"family_name": "Tyrin",
"given_name": "Nikita",
"orcid": "0009-0003-4206-6008"
},
{
"family_name": "Caiazzo",
"given_name": "Ilaria",
"orcid": "0000-0002-4770-5388",
"clpid": "Caiazzo-Ilaria"
},
{
"family_name": "Graham",
"given_name": "Matthew J.",
"orcid": "0000-0002-3168-0139",
"clpid": "Graham-M-J"
},
{
"family_name": "Laher",
"given_name": "Russ R.",
"orcid": "0000-0003-2451-5482",
"clpid": "Laher-R-R"
},
{
"family_name": "Kulkarni",
"given_name": "Shrinivas R.",
"orcid": "0000-0001-5390-8563",
"clpid": "Kulkarni-S-R"
},
{
"family_name": "Prince",
"given_name": "Thomas A.",
"orcid": "0000-0002-8850-3627",
"clpid": "Prince-T-A"
},
{
"family_name": "Riddle",
"given_name": "Reed",
"orcid": "0000-0002-0387-370X",
"clpid": "Riddle-Reed"
},
{
"family_name": "Vanderbosch",
"given_name": "Zachary P.",
"orcid": "0000-0002-0853-3464",
"clpid": "Vanderbosch-Zachary-P"
},
{
"family_name": "Wold",
"given_name": "Avery",
"orcid": "0000-0002-9998-6732",
"clpid": "Wold-Avery"
}
],
"abstract": "Aims. Cataclysmic variables (CVs) are compact binary systems in which a white dwarf accretes matter from a Roche-lobe-filling companion star. For this study we searched for new CVs in the Milky Way in the Chandra Source Catalog v2.0, cross-matched with Gaia Data Release 3 (DR3).
\nMethods. We identified new CV candidates by combining X-ray and optical data in a color-color diagram called the X-ray main sequence. We used two different cuts in this diagram to compile pure and optically variable samples of CV candidates. We undertook optical spectroscopic follow-up observations with the Keck and Palomar Observatories to confirm the nature of these sources.
\nResults. We assembled a sample of 25 887 Galactic X-ray sources and found 14 new CV candidates. Seven objects show X-ray and/or optical variability. All sources show X-ray luminosity in the 1029\u2005−\u20051032 erg s−1 range, and their X-ray spectra can be approximated by a power-law model with photon indices in the Γ\u2004∼\u20041\u2005−\u20053 range or an optically thin thermal emission model in the kT\u2004∼\u20041\u2005−\u200570 keV range. We spectroscopically confirmed four CVs, discovering two new polars, one low accretion rate polar and a WZ Sge-like low accretion rate CV. X-ray and optical properties of the other nine objects suggest that they are also CVs (likely magnetic or dwarf novae), and one other object could be an eclipsing binary, but revealing their true nature requires further observations.
\nConclusions. These results show that a joint X-ray and optical analysis can be a powerful tool for finding new CVs in large X-ray and optical catalogs. X-ray observations such as those by Chandra are particularly efficient at discovering magnetic and low accretion rate CVs, which could be missed by purely optical surveys.
",
"doi": "10.1051/0004-6361/202450734",
"issn": "0004-6361",
"publisher": "EDP Sciences",
"publication": "Astronomy & Astrophysics",
"publication_date": "2024-10",
"volume": "690",
"pages": "A374"
},
{
"id": "authors:nh5rv-h8f89",
"collection": "authors",
"collection_id": "nh5rv-h8f89",
"cite_using_url": "https://authors.library.caltech.edu/records/nh5rv-h8f89",
"type": "article",
"title": "The Zwicky Transient Facility Bright Transient Survey. III. BTSbot: Automated Identification and Follow-up of Bright Transients with Deep Learning",
"author": [
{
"family_name": "Rehemtulla",
"given_name": "Nabeel",
"orcid": "0000-0002-5683-2389"
},
{
"family_name": "Miller",
"given_name": "Adam A.",
"orcid": "0000-0001-9515-478X"
},
{
"family_name": "Jegou Du Laz",
"given_name": "Theophile",
"orcid": "0009-0003-6181-4526",
"clpid": "Jegou-Du-Laz-Theophile"
},
{
"family_name": "Coughlin",
"given_name": "Michael W.",
"orcid": "0000-0002-8262-2924"
},
{
"family_name": "Fremling",
"given_name": "Christoffer",
"orcid": "0000-0002-4223-103X",
"clpid": "Fremling-Christoffer"
},
{
"family_name": "Perley",
"given_name": "Daniel A.",
"orcid": "0000-0001-8472-1996"
},
{
"family_name": "Qin",
"given_name": "Yu-Jing",
"orcid": "0000-0003-3658-6026",
"clpid": "Qin-Yu-Jing"
},
{
"family_name": "Sollerman",
"given_name": "Jesper",
"orcid": "0000-0003-1546-6615"
},
{
"family_name": "Mahabal",
"given_name": "Ashish A.",
"orcid": "0000-0003-2242-0244",
"clpid": "Mahabal-A-A"
},
{
"family_name": "Laher",
"given_name": "Russ R.",
"orcid": "0000-0003-2451-5482",
"clpid": "Laher-R-R"
},
{
"family_name": "Riddle",
"given_name": "Reed",
"orcid": "0000-0002-0387-370X",
"clpid": "Riddle-Reed"
},
{
"family_name": "Rusholme",
"given_name": "Ben",
"orcid": "0000-0001-7648-4142",
"clpid": "Rusholme-Benjamin"
},
{
"family_name": "Kulkarni",
"given_name": "Shrinivas R.",
"orcid": "0000-0001-5390-8563",
"clpid": "Kulkarni-S-R"
}
],
"abstract": "\n
The Bright Transient Survey (BTS) aims to obtain a classification spectrum for all bright (mpeak ≤ 18.5 mag) extragalactic transients found in the Zwicky Transient Facility (ZTF) public survey. BTS critically relies on visual inspection (“scanning”) to select targets for spectroscopic follow-up, which, while effective, has required a significant time investment over the past ∼5 yr of ZTF operations. We present BTSbot, a multimodal convolutional neural network, which provides a bright transient score to individual ZTF detections using their image data and 25 extracted features. BTSbot is able to eliminate the need for daily human scanning by automatically identifying and requesting spectroscopic follow-up observations of new bright transient candidates. BTSbot recovers all bright transients in our test split and performs on par with scanners in terms of identification speed (on average, ∼1 hr quicker than scanners). We also find that BTSbot is not significantly impacted by any data shift by comparing performance across a concealed test split and a sample of very recent BTS candidates. BTSbot has been integrated into Fritz and Kowalski, ZTF’s first-party marshal and alert broker, and now sends automatic spectroscopic follow-up requests for the new transients it identifies. Between 2023 December and 2024 May, BTSbot selected 609 sources in real time, 96% of which were real extragalactic transients. With BTSbot and other automation tools, the BTS workflow has produced the first fully automatic end-to-end discovery and classification of a transient, representing a significant reduction in the human time needed to scan.
\n
Cataclysmic variables (CVs) that have evolved past the period minimum during their lifetimes are predicted to be systems with a brown dwarf donor. While population synthesis models predict that around 40–70 per cent of the Galactic CVs are post-period minimum systems referred to as ‘period bouncers’, only a few dozen confirmed systems are known. We report the study and characterization of a new eclipsing CV, SRGeJ041130.3+685350 (SRGeJ0411), discovered from a joint SRG/eROSITA and ZTF programme. The optical spectrum of SRGeJ0411 shows prominent hydrogen and helium emission lines, typical for CVs. We obtained optical high-speed photometry to confirm the eclipse of SRGeJ0411 and determine the orbital period to be Porb ≈ 97.530 min. The spectral energy distribution suggests that the donor has an effective temperature of \u2272 1800 K. We constrain the donor mass with the period–density relationship for Roche lobe-filling stars and find that Mdonor \u2272 0.04 M\u2299. The binary parameters are consistent with evolutionary models for post-period minimum CVs, suggesting that SRGeJ0411 is a new period bouncer. The optical emission lines of SRGeJ0411 are single-peaked despite the system being eclipsing, which is typically only seen due to stream-fed accretion in polars. X-ray spectroscopy hints that the white dwarf in SRGeJ0411 could be magnetic, but verifying the magnetic nature of SRGeJ0411 requires further investigation. The lack of optical outbursts has made SRGeJ0411 elusive in previous surveys, and joint X-ray and optical surveys highlight the potential for discovering similar systems in the near future.
",
"doi": "10.1093/mnras/stae012",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2024-02",
"series_number": "1",
"volume": "528",
"issue": "1",
"pages": "676-692"
},
{
"id": "authors:ajkck-grb73",
"collection": "authors",
"collection_id": "ajkck-grb73",
"cite_using_url": "https://authors.library.caltech.edu/records/ajkck-grb73",
"type": "article",
"title": "Probing the Low-mass End of Core-collapse Supernovae Using a Sample of Strongly-stripped Calcium-rich Type IIb Supernovae from the Zwicky Transient Facility",
"author": [
{
"family_name": "Das",
"given_name": "Kaustav K.",
"orcid": "0000-0001-8372-997X",
"clpid": "Das-Kaustav-K"
},
{
"family_name": "Kasliwal",
"given_name": "Mansi M.",
"orcid": "0000-0002-5619-4938",
"clpid": "Kasliwal-M-M"
},
{
"family_name": "Fremling",
"given_name": "Christoffer",
"orcid": "0000-0002-4223-103X",
"clpid": "Fremling-Christoffer"
},
{
"family_name": "Yang",
"given_name": "Sheng",
"orcid": "0000-0003-1546-6615",
"clpid": "Yang-Sheng"
},
{
"family_name": "Schulze",
"given_name": "Steve",
"orcid": "0000-0001-6797-1889",
"clpid": "Schulze-Steve"
},
{
"family_name": "Sit",
"given_name": "Tawny",
"orcid": "0000-0001-8208-9755",
"clpid": "Sit-Tawny"
},
{
"family_name": "De",
"given_name": "Kishalay",
"orcid": "0000-0002-8989-0542",
"clpid": "De-Kishalay"
},
{
"family_name": "Tzanidakis",
"given_name": "Anastasios",
"orcid": "0000-0003-0484-3331",
"clpid": "Tzanidakis-Anastasios"
},
{
"family_name": "Perley",
"given_name": "Daniel A.",
"orcid": "0000-0001-8472-1996",
"clpid": "Perley-Daniel-A"
},
{
"family_name": "Anand",
"given_name": "Shreya",
"orcid": "0000-0003-3768-7515",
"clpid": "Anand-Shreya"
},
{
"family_name": "Andreoni",
"given_name": "Igor",
"orcid": "0000-0002-8977-1498",
"clpid": "Andreoni-Igor"
},
{
"family_name": "Barbarino",
"given_name": "C.",
"orcid": "0000-0002-3821-6144",
"clpid": "Barbarino-Cristina"
},
{
"family_name": "Brudge",
"given_name": "K.",
"clpid": "Brudge-K"
},
{
"family_name": "Drake",
"given_name": "Andrew",
"orcid": "0000-0003-0228-6594",
"clpid": "Drake-Andrew-J"
},
{
"family_name": "Gal-Yam",
"given_name": "Avishay",
"orcid": "0000-0002-3653-5598",
"clpid": "Gal-Yam-Avishay"
},
{
"family_name": "Laher",
"given_name": "Russ R.",
"orcid": "0000-0003-2451-5482",
"clpid": "Laher-R-R"
},
{
"family_name": "Karambelkar",
"given_name": "Viraj",
"orcid": "0000-0003-2758-159X",
"clpid": "Karambelkar-Viraj"
},
{
"family_name": "Kulkarni",
"given_name": "S. R.",
"orcid": "0000-0001-5390-8563",
"clpid": "Kulkarni-S-R"
},
{
"family_name": "Masci",
"given_name": "Frank J.",
"orcid": "0000-0002-8532-9395",
"clpid": "Masci-Frank-J"
},
{
"family_name": "Medford",
"given_name": "Michael S.",
"orcid": "0000-0002-7226-0659",
"clpid": "Medford-Michael-S"
},
{
"family_name": "Polin",
"given_name": "Abigail",
"orcid": "0000-0002-1633-6495",
"clpid": "Polin-Abigail"
},
{
"family_name": "Reedy",
"given_name": "Harrison",
"clpid": "Reedy-Harrison"
},
{
"family_name": "Riddle",
"given_name": "Reed",
"orcid": "0000-0002-0387-370X",
"clpid": "Riddle-Reed"
},
{
"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": "Yan",
"given_name": "Lin",
"orcid": "0000-0003-1710-9339",
"clpid": "Yan-Lin"
},
{
"family_name": "Yang",
"given_name": "Yi",
"orcid": "0000-0002-6535-8500",
"clpid": "Yang-Yi"
},
{
"family_name": "Yao",
"given_name": "Yuhan",
"orcid": "0000-0001-6747-8509",
"clpid": "Yao-Yuhan"
}
],
"abstract": "The fate of stars in the zero-age main-sequence (ZAMS) range \u22488\u201312 M_\u2299 is unclear. They could evolve to form white dwarfs or explode as electron-capture supernovae (SNe) or iron core-collapse SNe (CCSNe). Even though the initial mass function indicates that this mass range should account for over 40% of all CCSN progenitors, few have been observationally confirmed, likely due to the faintness and rapid evolution of some of these transients. In this paper, we present a sample of nine Ca-rich/O-poor Type IIb SNe detected by the Zwicky Transient Facility with progenitors likely in this mass range. These sources have a [Ca ii] \u03bb \u03bb7291, 7324/[O i] \u03bb \u03bb6300, 6364 flux ratio of \u22732 in their nebular spectra. Comparing the measured [O i] luminosity (\u227210\u00b3\u2079 erg s\u207b\u00b9) and derived oxygen mass (\u22480.01 M_\u2299) with theoretical models, we infer that the progenitor ZAMS mass for these explosions is less than 12 M _\u2299. The ejecta properties (M_(ej) \u2272 1 M_\u2299 and E_(kin) \u223c 10\u2075\u2070 erg) are also consistent. The low ejecta mass of these sources indicates a class of strongly-stripped SNe that is a transition between the regular stripped-envelope SNe and ultra-stripped SNe. The progenitor could be stripped by a main-sequence companion and result in the formation of a neutron star\u2212main sequence binary. Such binaries have been suggested to be progenitors of neutron star\u2212white dwarf systems that could merge within a Hubble time and be detectable with LISA.
",
"doi": "10.3847/1538-4357/acfeeb",
"issn": "0004-637X",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal",
"publication_date": "2023-12-10",
"series_number": "1",
"volume": "959",
"issue": "1",
"pages": "12"
},
{
"id": "authors:c7fsp-s7g30",
"collection": "authors",
"collection_id": "c7fsp-s7g30",
"cite_using_url": "https://authors.library.caltech.edu/records/c7fsp-s7g30",
"type": "article",
"title": "Minutes-duration optical flares with supernova luminosities",
"author": [
{
"family_name": "Ho",
"given_name": "Anna Y. Q.",
"orcid": "0000-0002-9017-3567",
"clpid": "Ho-Anna-Y-Q"
},
{
"family_name": "Perley",
"given_name": "Daniel A.",
"orcid": "0000-0001-8472-1996"
},
{
"family_name": "Chen",
"given_name": "Ping",
"orcid": "0000-0003-0853-6427"
},
{
"family_name": "Schulze",
"given_name": "Steve",
"orcid": "0000-0001-6797-1889"
},
{
"family_name": "Dhillon",
"given_name": "Vik",
"orcid": "0000-0003-4236-9642"
},
{
"family_name": "Kumar",
"given_name": "Harsh",
"orcid": "0000-0003-0871-4641"
},
{
"family_name": "Suresh",
"given_name": "Aswin",
"orcid": "0009-0005-8230-030X"
},
{
"family_name": "Swain",
"given_name": "Vishwajeet",
"orcid": "0000-0002-7942-8477"
},
{
"family_name": "Bremer",
"given_name": "Michael",
"orcid": "0000-0001-7511-3745"
},
{
"family_name": "Smartt",
"given_name": "Stephen J.",
"orcid": "0000-0002-8229-1731"
},
{
"family_name": "Anderson",
"given_name": "Joseph P.",
"orcid": "0000-0003-0227-3451"
},
{
"family_name": "Anupama",
"given_name": "G. C.",
"orcid": "0000-0003-3533-7183"
},
{
"family_name": "Awiphan",
"given_name": "Supachai",
"orcid": "0000-0003-3251-3583"
},
{
"family_name": "Barway",
"given_name": "Sudhanshu",
"orcid": "0000-0002-3927-5402"
},
{
"family_name": "Bellm",
"given_name": "Eric C.",
"orcid": "0000-0001-8018-5348"
},
{
"family_name": "Ben-Ami",
"given_name": "Sagi",
"orcid": "0000-0001-6760-3074"
},
{
"family_name": "Bhalerao",
"given_name": "Varun",
"orcid": "0000-0002-6112-7609"
},
{
"family_name": "de Boer",
"given_name": "Thomas",
"orcid": "0000-0001-5486-2747"
},
{
"family_name": "Brink",
"given_name": "Thomas G.",
"orcid": "0000-0001-5955-2502"
},
{
"family_name": "Burruss",
"given_name": "Rick",
"clpid": "Burruss-Rick-S"
},
{
"family_name": "Chandra",
"given_name": "Poonam",
"orcid": "0000-0002-0844-6563"
},
{
"family_name": "Chen",
"given_name": "Ting-Wan",
"orcid": "0000-0002-1066-6098"
},
{
"family_name": "Chen",
"given_name": "Wen-Ping",
"orcid": "0000-0003-0262-272X"
},
{
"family_name": "Cooke",
"given_name": "Jeff",
"orcid": "0000-0001-5703-2108"
},
{
"family_name": "Coughlin",
"given_name": "Michael W.",
"orcid": "0000-0002-8262-2924"
},
{
"family_name": "Das",
"given_name": "Kaustav K.",
"clpid": "Das-Kaustav-K"
},
{
"family_name": "Drake",
"given_name": "Andrew J.",
"orcid": "0000-0003-0228-6594",
"clpid": "Drake-Andrew-J"
},
{
"family_name": "Filippenko",
"given_name": "Alexei V.",
"orcid": "0000-0003-3460-0103"
},
{
"family_name": "Freeburn",
"given_name": "James",
"orcid": "0009-0006-7990-0547"
},
{
"family_name": "Fremling",
"given_name": "Christoffer",
"orcid": "0000-0002-4223-103X",
"clpid": "Fremling-Christoffer"
},
{
"family_name": "Fulton",
"given_name": "Michael D.",
"orcid": "0000-0003-1916-0664"
},
{
"family_name": "Gal-Yam",
"given_name": "Avishay",
"orcid": "0000-0002-3653-5598"
},
{
"family_name": "Galbany",
"given_name": "Llu\u00eds",
"orcid": "0000-0002-1296-6887"
},
{
"family_name": "Gao",
"given_name": "Hua",
"orcid": "0000-0003-1015-5367"
},
{
"family_name": "Graham",
"given_name": "Matthew J.",
"orcid": "0000-0002-3168-0139",
"clpid": "Graham-M-J"
},
{
"family_name": "Gromadzki",
"given_name": "Mariusz",
"orcid": "0000-0002-1650-1518"
},
{
"family_name": "Guti\u00e9rrez",
"given_name": "Claudia P.",
"orcid": "0000-0003-2375-2064"
},
{
"family_name": "Hinds",
"given_name": "K.-Ryan",
"orcid": "0000-0002-0129-806X"
},
{
"family_name": "Inserra",
"given_name": "Cosimo",
"orcid": "0000-0002-3968-4409"
},
{
"family_name": "AJ",
"given_name": "Nayana",
"orcid": "0000-0002-8070-5400"
},
{
"family_name": "Karambelkar",
"given_name": "Viraj",
"orcid": "0000-0003-2758-159X",
"clpid": "Karambelkar-Viraj"
},
{
"family_name": "Kasliwal",
"given_name": "Mansi M.",
"orcid": "0000-0002-5619-4938",
"clpid": "Kasliwal-M-M"
},
{
"family_name": "Kulkarni",
"given_name": "Shri",
"orcid": "0000-0001-5390-8563",
"clpid": "Kulkarni-S-R"
},
{
"family_name": "M\u00fcller-Bravo",
"given_name": "Tom\u00e1s E.",
"orcid": "0000-0003-3939-7167"
},
{
"family_name": "Magnier",
"given_name": "Eugene A.",
"orcid": "0000-0002-7965-2815"
},
{
"family_name": "Mahabal",
"given_name": "Ashish A.",
"orcid": "0000-0003-2242-0244",
"clpid": "Mahabal-A-A"
},
{
"family_name": "Moore",
"given_name": "Thomas",
"orcid": "0000-0001-8385-3727"
},
{
"family_name": "Ngeow",
"given_name": "Chow-Choong",
"orcid": "0000-0001-8771-7554"
},
{
"family_name": "Nicholl",
"given_name": "Matt",
"orcid": "0000-0002-2555-3192"
},
{
"family_name": "Ofek",
"given_name": "Eran O.",
"orcid": "0000-0002-6786-8774"
},
{
"family_name": "Omand",
"given_name": "Conor M. B.",
"orcid": "0000-0002-9646-8710"
},
{
"family_name": "Onori",
"given_name": "Francesca",
"orcid": "0000-0001-6286-1744"
},
{
"family_name": "Pan",
"given_name": "Yen-Chen",
"orcid": "0000-0001-8415-6720"
},
{
"family_name": "Pessi",
"given_name": "Priscila J.",
"orcid": "0000-0002-8041-8559"
},
{
"family_name": "Petitpas",
"given_name": "Glen"
},
{
"family_name": "Polishook",
"given_name": "David",
"orcid": "0000-0002-6977-3146"
},
{
"family_name": "Poshyachinda",
"given_name": "Saran"
},
{
"family_name": "Pursiainen",
"given_name": "Miika",
"orcid": "0000-0003-4663-4300"
},
{
"family_name": "Riddle",
"given_name": "Reed",
"orcid": "0000-0002-0387-370X",
"clpid": "Riddle-Reed"
},
{
"family_name": "Rodriguez",
"given_name": "Antonio C.",
"orcid": "0000-0003-4189-9668",
"clpid": "Rodriguez-Antonio-C"
},
{
"family_name": "Rusholme",
"given_name": "Ben",
"orcid": "0000-0001-7648-4142",
"clpid": "Rusholme-Benjamin-A"
},
{
"family_name": "Segre",
"given_name": "Enrico",
"orcid": "0000-0002-0913-3083"
},
{
"family_name": "Sharma",
"given_name": "Yashvi",
"orcid": "0000-0003-4531-1745",
"clpid": "Sharma-Yashvi"
},
{
"family_name": "Smith",
"given_name": "Ken W.",
"orcid": "0000-0001-9535-3199"
},
{
"family_name": "Sollerman",
"given_name": "Jesper",
"orcid": "0000-0003-1546-6615"
},
{
"family_name": "Srivastav",
"given_name": "Shubham",
"orcid": "0000-0003-4524-6883"
},
{
"family_name": "Strotjohann",
"given_name": "Nora Linn",
"orcid": "0000-0002-4667-6730"
},
{
"family_name": "Suhr",
"given_name": "Mark"
},
{
"family_name": "Svinkin",
"given_name": "Dmitry",
"orcid": "0000-0002-2208-2196"
},
{
"family_name": "Wang",
"given_name": "Yanan",
"orcid": "0000-0003-3207-5237"
},
{
"family_name": "Wiseman",
"given_name": "Philip",
"orcid": "0000-0002-3073-1512"
},
{
"family_name": "Wold",
"given_name": "Avery",
"orcid": "0000-0002-9998-6732",
"clpid": "Wold-Avery"
},
{
"family_name": "Yang",
"given_name": "Sheng",
"orcid": "0000-0002-2898-6532"
},
{
"family_name": "Yang",
"given_name": "Yi",
"orcid": "0000-0002-6535-8500"
},
{
"family_name": "Yao",
"given_name": "Yuhan",
"orcid": "0000-0001-6747-8509",
"clpid": "Yao-Yuhan"
},
{
"family_name": "Young",
"given_name": "David R.",
"orcid": "0000-0002-1229-2499"
},
{
"family_name": "Zheng",
"given_name": "WeiKang",
"orcid": "0000-0002-2636-6508"
}
],
"abstract": "In recent years, certain luminous extragalactic optical transients have been observed to last only a few days1. Their short observed duration implies a different powering mechanism from the most common luminous extragalactic transients (supernovae), whose timescale is weeks2. Some short-duration transients, most notably AT2018cow (ref.\u20093), show blue optical colours and bright radio and X-ray emission4. Several AT2018cow-like transients have shown hints of a long-lived embedded energy source5, such as X-ray variability6,7, prolonged ultraviolet emission8, a tentative X-ray quasiperiodic oscillation9,10 and large energies coupled to fast (but subrelativistic) radio-emitting ejecta11,12. Here we report observations of minutes-duration optical flares in the aftermath of an AT2018cow-like transient, AT2022tsd (the 'Tasmanian Devil'). The flares occur over a period of months, are highly energetic and are probably nonthermal, implying that they arise from a near-relativistic outflow or jet. Our observations confirm that, in some AT2018cow-like transients, the embedded energy source is a compact object, either a magnetar or an accreting black hole.
",
"doi": "10.1038/s41586-023-06673-6",
"issn": "0028-0836",
"publisher": "Nature Publishing Group",
"publication": "Nature",
"publication_date": "2023-11-30",
"series_number": "7879",
"volume": "623",
"issue": "7879",
"pages": "927-931"
},
{
"id": "authors:hbgpj-4f191",
"collection": "authors",
"collection_id": "hbgpj-4f191",
"cite_using_url": "https://authors.library.caltech.edu/records/hbgpj-4f191",
"type": "article",
"title": "Tidal Disruption Event Demographics with the Zwicky Transient Facility: Volumetric Rates, Luminosity Function, and Implications for the Local Black Hole Mass Function",
"author": [
{
"family_name": "Yao",
"given_name": "Yuhan",
"orcid": "0000-0001-6747-8509",
"clpid": "Yao-Yuhan"
},
{
"family_name": "Ravi",
"given_name": "Vikram",
"orcid": "0000-0002-7252-5485",
"clpid": "Ravi-Vikram"
},
{
"family_name": "Gezari",
"given_name": "Suvi",
"orcid": "0000-0003-3703-5154"
},
{
"family_name": "van Velzen",
"given_name": "Sjoert",
"orcid": "0000-0002-3859-8074"
},
{
"family_name": "Lu",
"given_name": "Wenbin",
"orcid": "0000-0002-1568-7461"
},
{
"family_name": "Schulze",
"given_name": "Steve",
"orcid": "0000-0001-6797-1889"
},
{
"family_name": "Somalwar",
"given_name": "Jean J.",
"orcid": "0000-0001-8426-5732",
"clpid": "Somalwar-Jean-J"
},
{
"family_name": "Kulkarni",
"given_name": "S. R.",
"orcid": "0000-0001-5390-8563",
"clpid": "Kulkarni-S-R"
},
{
"family_name": "Hammerstein",
"given_name": "Erica",
"orcid": "0000-0002-5698-8703"
},
{
"family_name": "Nicholl",
"given_name": "Matt",
"orcid": "0000-0002-2555-3192"
},
{
"family_name": "Graham",
"given_name": "Matthew J.",
"orcid": "0000-0002-3168-0139",
"clpid": "Graham-M-J"
},
{
"family_name": "Perley",
"given_name": "Daniel A.",
"orcid": "0000-0001-8472-1996"
},
{
"family_name": "Cenko",
"given_name": "S. Bradley",
"orcid": "0000-0003-1673-970X"
},
{
"family_name": "Stein",
"given_name": "Robert",
"orcid": "0000-0003-2434-0387",
"clpid": "Stein-Robert"
},
{
"family_name": "Ricarte",
"given_name": "Angelo",
"orcid": "0000-0001-5287-0452"
},
{
"family_name": "Chadayammuri",
"given_name": "Urmila"
},
{
"family_name": "Quataert",
"given_name": "Eliot",
"orcid": "0000-0001-9185-5044"
},
{
"family_name": "Bellm",
"given_name": "Eric C.",
"orcid": "0000-0001-8018-5348"
},
{
"family_name": "Bloom",
"given_name": "Joshua S.",
"orcid": "0000-0002-7777-216X"
},
{
"family_name": "Dekany",
"given_name": "Richard",
"orcid": "0000-0002-5884-7867",
"clpid": "Dekany-Richard"
},
{
"family_name": "Drake",
"given_name": "Andrew J.",
"orcid": "0000-0003-0228-6594",
"clpid": "Drake-Andrew-J"
},
{
"family_name": "Groom",
"given_name": "Steven L.",
"orcid": "0000-0001-5668-3507",
"clpid": "Groom-Steven-L"
},
{
"family_name": "Mahabal",
"given_name": "Ashish A.",
"orcid": "0000-0003-2242-0244",
"clpid": "Mahabal-A-A"
},
{
"family_name": "Prince",
"given_name": "Thomas A.",
"orcid": "0000-0002-8850-3627",
"clpid": "Prince-T-A"
},
{
"family_name": "Riddle",
"given_name": "Reed",
"orcid": "0000-0002-0387-370X",
"clpid": "Riddle-Reed"
},
{
"family_name": "Rusholme",
"given_name": "Ben",
"orcid": "0000-0001-7648-4142",
"clpid": "Rusholme-Ben"
},
{
"family_name": "Sharma",
"given_name": "Yashvi",
"orcid": "0000-0003-4531-1745",
"clpid": "Sharma-Yashvi"
},
{
"family_name": "Sollerman",
"given_name": "Jesper",
"orcid": "0000-0003-1546-6615"
},
{
"family_name": "Yan",
"given_name": "Lin",
"orcid": "0000-0003-1710-9339",
"clpid": "Yan-Lin"
}
],
"abstract": "We conduct a systematic tidal disruption event (TDE) demographics analysis using the largest sample of optically selected TDEs. A flux-limited, spectroscopically complete sample of 33 TDEs is constructed using the Zwicky Transient Facility over 3 yr (from 2018 October to 2021 September). We infer the black hole (BH) mass (MBH) with host galaxy scaling relations, showing that the sample MBH ranges from 105.1M\u2299 to 108.2M\u2299. We developed a survey efficiency corrected maximum volume method to infer the rates. The rest-frame g-band luminosity function can be well described by a broken power law of \u03d5(Lg)∝[(Lg/Lbk)0.3+(Lg/Lbk)2.6]−1, with Lbk = 1043.1 erg s−1. In the BH mass regime of 105.3 \u2272 (MBH/M\u2299) \u2272 107.3, the TDE mass function follows \u03d5(MBH)∝MBH−0.25, which favors a flat local BH mass function (dnBH/dlogMBH≈constant). We confirm the significant rate suppression at the high-mass end (MBH \u2273 107.5M\u2299), which is consistent with theoretical predictions considering direct capture of hydrogen-burning stars by the event horizon. At a host galaxy mass of Mgal ∼ 1010M\u2299, the average optical TDE rate is ≈3.2 × 10−5 galaxy−1 yr−1. We constrain the optical TDE rate to be [3.7, 7.4, and 1.6] × 10−5 galaxy−1 yr−1 in galaxies with red, green, and blue colors.
",
"doi": "10.3847/2041-8213/acf216",
"issn": "2041-8205",
"publisher": "American Astronomical Society",
"publication": "Astrophysical Journal Letters",
"publication_date": "2023-09-20",
"series_number": "1",
"volume": "955",
"issue": "1",
"pages": "L6"
},
{
"id": "authors:amr3w-ssw15",
"collection": "authors",
"collection_id": "amr3w-ssw15",
"cite_using_url": "https://authors.library.caltech.edu/records/amr3w-ssw15",
"type": "article",
"title": "Orbital Decay in an Accreting and Eclipsing 13.7 Minute Orbital Period Binary with a Luminous Donor",
"author": [
{
"family_name": "Burdge",
"given_name": "Kevin B.",
"orcid": "0000-0002-7226-836X"
},
{
"family_name": "El-Badry",
"given_name": "Kareem",
"orcid": "0000-0002-6871-1752",
"clpid": "El-Badry-Kareem"
},
{
"family_name": "Rappaport",
"given_name": "Saul",
"orcid": "0000-0003-3182-5569"
},
{
"family_name": "Sunny Wong",
"given_name": "Tin Long",
"orcid": "0000-0001-9195-7390"
},
{
"family_name": "Bauer",
"given_name": "Evan B.",
"orcid": "0000-0002-4791-6724"
},
{
"family_name": "Bildsten",
"given_name": "Lars",
"orcid": "0000-0001-8038-6836"
},
{
"family_name": "Caiazzo",
"given_name": "Ilaria",
"orcid": "0000-0002-4770-5388",
"clpid": "Caiazzo-Ilaria"
},
{
"family_name": "Chakrabarty",
"given_name": "Deepto",
"orcid": "0000-0001-8804-8946"
},
{
"family_name": "Chickles",
"given_name": "Emma",
"orcid": "0000-0003-4780-4105"
},
{
"family_name": "Graham",
"given_name": "Matthew J.",
"orcid": "0000-0002-3168-0139",
"clpid": "Graham-M-J"
},
{
"family_name": "Kara",
"given_name": "Erin",
"orcid": "0000-0003-0172-0854"
},
{
"family_name": "Kulkarni",
"given_name": "S. R.",
"orcid": "0000-0001-5390-8563",
"clpid": "Kulkarni-S-R"
},
{
"family_name": "Marsh",
"given_name": "Thomas R.",
"orcid": "0000-0002-2498-7589"
},
{
"family_name": "Nynka",
"given_name": "Melania",
"orcid": "0000-0002-3310-1946"
},
{
"family_name": "Prince",
"given_name": "Thomas A.",
"orcid": "0000-0002-8850-3627",
"clpid": "Prince-T-A"
},
{
"family_name": "Simcoe",
"given_name": "Robert A.",
"orcid": "0000-0003-3769-9559"
},
{
"family_name": "van Roestel",
"given_name": "Jan",
"orcid": "0000-0002-2626-2872",
"clpid": "van-Roestel-Jan"
},
{
"family_name": "Vanderbosch",
"given_name": "Zach",
"orcid": "0000-0002-0853-3464",
"clpid": "Vanderbosch-Zach"
},
{
"family_name": "Bellm",
"given_name": "Eric C.",
"orcid": "0000-0001-8018-5348"
},
{
"family_name": "Dekany",
"given_name": "Richard G.",
"orcid": "0000-0002-5884-7867",
"clpid": "Dekany-Richard"
},
{
"family_name": "Drake",
"given_name": "Andrew J.",
"orcid": "0000-0003-0228-6594",
"clpid": "Drake-Andrew-J"
},
{
"family_name": "Helou",
"given_name": "George",
"orcid": "0000-0003-3367-3415",
"clpid": "Helou-G"
},
{
"family_name": "Masci",
"given_name": "Frank J.",
"orcid": "0000-0002-8532-9395",
"clpid": "Masci-Frank"
},
{
"family_name": "Milburn",
"given_name": "Jennifer",
"clpid": "Milburn-Jennifer"
},
{
"family_name": "Riddle",
"given_name": "Reed",
"orcid": "0000-0002-0387-370X",
"clpid": "Riddle-Reed"
},
{
"family_name": "Rusholme",
"given_name": "Ben",
"orcid": "0000-0001-7648-4142",
"clpid": "Rusholme-Benjamin"
},
{
"family_name": "Smith",
"given_name": "Roger",
"orcid": "0000-0001-7062-9726",
"clpid": "Smith-R-M"
}
],
"abstract": "\n
We report the discovery of ZTF J0127+5258, a compact mass-transferring binary with an orbital period of 13.7 minutes. The system contains a white dwarf accretor, which likely originated as a post–common envelope carbon–oxygen (CO) white dwarf, and a warm donor (Teff,donor = 16,400 ± 1000 K). The donor probably formed during a common envelope phase between the CO white dwarf and an evolving giant that left behind a helium star or white dwarf in a close orbit with the CO white dwarf. We measure gravitational wave–driven orbital inspiral with ∼51σ significance, which yields a joint constraint on the component masses and mass transfer rate. While the accretion disk in the system is dominated by ionized helium emission, the donor exhibits a mixture of hydrogen and helium absorption lines. Phase-resolved spectroscopy yields a donor radial velocity semiamplitude of 771 ± 27 km s−1, and high-speed photometry reveals that the system is eclipsing. We detect a Chandra X-ray counterpart with LX ∼ 3 × 1031 erg s−1. Depending on the mass transfer rate, the system will likely either evolve into a stably mass-transferring helium cataclysmic variable, merge to become an R CrB star, or explode as a Type Ia supernova in the next million years. We predict that the Laser Space Interferometer Antenna (LISA) will detect the source with a signal-to-noise ratio of 24 ± 6 after 4 yr of observations. The system is the first LISA-loud mass-transferring binary with an intrinsically luminous donor, a class of sources that provide the opportunity to leverage the synergy between optical and infrared time domain surveys, X-ray facilities, and gravitational-wave observatories to probe general relativity, accretion physics, and binary evolution.
\n
\n
SkyPortal is an open-source software package designed to discover interesting transients efficiently, manage follow-up, perform characterization, and visualize the results. By enabling fast access to archival and catalog data, crossmatching heterogeneous data streams, and the triggering and monitoring of on-demand observations for further characterization, a SkyPortal-based platform has been operating at scale for >2 yr for the Zwicky Transient Facility Phase II community, with hundreds of users, containing tens of millions of time-domain sources, interacting with dozens of telescopes, and enabling community reporting. While SkyPortal emphasizes rich user experiences across common front-end workflows, recognizing that scientific inquiry is increasingly performed programmatically, SkyPortal also surfaces an extensive and well-documented application programming interface system. From back-end and front-end software to data science analysis tools and visualization frameworks, the SkyPortal design emphasizes the reuse and leveraging of best-in-class approaches, with a strong extensibility ethos. For instance, SkyPortal now leverages ChatGPT large language models to generate and surface source-level human-readable summaries automatically. With the imminent restart of the next generation of gravitational-wave detectors, SkyPortal now also includes dedicated multimessenger features addressing the requirements of rapid multimessenger follow-up: multitelescope management, team/group organizing interfaces, and crossmatching of multimessenger data streams with time-domain optical surveys, with interfaces sufficiently intuitive for newcomers to the field. This paper focuses on the detailed implementations, capabilities, and early science results that establish SkyPortal as a community software package ready to take on the data science challenges and opportunities presented by this next chapter in the multimessenger era.
\n
We present a sample of 14 hydrogen-rich superluminous supernovae (SLSNe II) from the Zwicky Transient Facility (ZTF) between 2018 and 2020. We include all classified SLSNe with peaks M_g < −20 mag with observed broad but not narrow Balmer emission, corresponding to roughly 20 per cent of all hydrogen-rich SLSNe in ZTF phase I. We examine the light curves and spectra of SLSNe II and attempt to constrain their power source using light-curve models. The brightest events are photometrically and spectroscopically similar to the prototypical SN 2008es, while others are found spectroscopically more reminiscent of non-superluminous SNe II, especially SNe II-L. \u2075\u2076Ni decay as the primary power source is ruled out. Light-curve models generally cannot distinguish between circumstellar interaction (CSI) and a magnetar central engine, but an excess of ultraviolet (UV) emission signifying CSI is seen in most of the SNe with UV data, at a wide range of photometric properties. Simultaneously, the broad H α profiles of the brightest SLSNe II can be explained through electron scattering in a symmetric circumstellar medium (CSM). In other SLSNe II without narrow lines, the CSM may be confined and wholly overrun by the ejecta. CSI, possibly involving mass lost in recent eruptions, is implied to be the dominant power source in most SLSNe II, and the diversity in properties is likely the result of different mass loss histories. Based on their radiated energy, an additional power source may be required for the brightest SLSNe II, however – possibly a central engine combined with CSI.
",
"doi": "10.1093/mnras/stac2218",
"issn": "0035-8711",
"publisher": "Royal Astronomical Society",
"publication": "Monthly Notices of the Royal Astronomical Society",
"publication_date": "2022-10",
"series_number": "1",
"volume": "516",
"issue": "1",
"pages": "1193-1218"
}
]