Статья

iPTF15eqv: Multiwavelength Exposé of a Peculiar Calcium-rich Transient

D. MilisavljevicHarvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138, USAD. PatnaudeHarvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138, USAJ. C. RaymondHarvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138, USAMaria R. DroutThe Observatories of the Carnegie Institution for Science, 813 Santa Barbara St., Pasadena, CA 91101, USAR. MarguttiCenter for Cosmology and Particle Physics, New York University, New York, NY 10003, USAA. KambleHarvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138, USARyan ChornockAstrophysical Institute, Department of Physics and Astronomy, 251B Clippinger Lab, Ohio University, Athens, OH 45701, USAJames GuillochonHarvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138, USANathan E. SandersHarvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138, USAJ. ParrentHarvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138, USALorenzo LovisariHarvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138, USAI. V. ChilingarianHarvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138, USAPeter ChallisHarvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138, USARobert P. KirshnerHarvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138, USAMatthew T. PennyDepartment of Astronomy, Ohio State University, 140 West 18th Ave., Columbus, OH 43210, USAKoichi ItagakiJ. J. EldridgeDepartment of Physics, University of Auckland, Private Bag 92019, Auckland, New ZealandTakashi J. MoriyaDivision of Theoretical Astronomy, National Astronomical Observatory of Japan, National Institutes of Natural Sciences, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan

2017en

ABI

Аннотация

Abstract The progenitor systems of the class of “Ca-rich transients” is a key open issue in time domain astrophysics. These intriguing objects exhibit unusually strong calcium line emissions months after explosion, fall within an intermediate luminosity range, are often found at large projected distances from their host galaxies, and may play a vital role in enriching galaxies and the intergalactic medium. Here we present multiwavelength observations of iPTF15eqv in NGC 3430, which exhibits a unique combination of properties that bridge those observed in Ca-rich transients and SNe Ib/c. iPTF15eqv has among the highest [Ca ii ]/[O i ] emission line ratios observed to date, yet is more luminous and decays more slowly than other Ca-rich transients. Optical and near-infrared photometry and spectroscopy reveal signatures consistent with the supernova explosion of a star that was stripped of its H-rich envelope via binary interaction. Distinct chemical abundances and ejecta kinematics suggest that the core collapse occurred through electron-capture processes. Deep limits on possible radio emission made with the Jansky Very Large Array imply a clean environment ( n ≲ 0.1 cm −3 ) within a radius of cm. Chandra X-ray Observatory observations rule out alternative scenarios involving the tidal disruption of a white dwarf (WD) by a black hole, for masses >100 M ⊙ . Our results challenge the notion that spectroscopically classified Ca-rich transients only originate from WD progenitor systems, complicate the view that they are all associated with large ejection velocities, and indicate that their chemical abundances may vary widely between events.

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Идентификаторы

DOI: 10.3847/1538-4357/aa7d9f

Цитирования и источники

Цитирований: 2Использованных источников: 0

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