Статья

SN 2019yvq Does Not Conform to SN Ia Explosion Models

M. A. TuckerInstitute for Astronomy, University of Hawai’i at Manoa, 2680 Woodlawn Drive, Hawai’i, HI 96822, USA; [email protected]C. AshallInstitute for Astronomy, University of Hawai’i at Manoa, 2680 Woodlawn Drive, Hawai’i, HI 96822, USA; [email protected]B. J. ShappeeInstitute for Astronomy, University of Hawai’i at Manoa, 2680 Woodlawn Drive, Hawai’i, HI 96822, USA; [email protected]Patrick J. VallelyDepartment of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210, USAC. S. KochanekCenter for Cosmology and AstroParticle Physics, The Ohio State University, 191 W. Woodruff Avenue, Columbus, OH 43210, USAM. E. HuberInstitute for Astronomy, University of Hawai’i at Manoa, 2680 Woodlawn Drive, Hawai’i, HI 96822, USA; [email protected]Gagandeep S. AnandInstitute for Astronomy, University of Hawai’i at Manoa, 2680 Woodlawn Drive, Hawai’i, HI 96822, USA; [email protected]J. V. KeaneInstitute for Astronomy, University of Hawai’i at Manoa, 2680 Woodlawn Drive, Hawai’i, HI 96822, USA; [email protected]E. Y. HsiaoDepartment of Physics, Florida State University, Tallahassee, FL 32306, USAT. W. S. HoloienThe Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101, USA

2021en

ABI

Аннотация

Abstract We present new photometric and spectroscopic observations of SN 2019yvq, a Type Ia supernova (SN Ia) exhibiting several peculiar properties including an excess of UV/optical flux within days of explosion, a high Si ii velocity, and a low peak luminosity. Photometry near the time of first light places new constraints on the rapid rise of the UV/optical flux excess. A near-infrared spectrum at +173 days after maximum light places strict limits on the presence of H or He emission, effectively excluding the presence of a nearby nondegenerate star at the time of explosion. New optical spectra, acquired at +128 and +150 days after maximum light, confirm the presence of [Ca ii ] λ 7300 and persistent Ca ii NIR triplet emission as SN 2019yvq transitions into the nebular phase. The lack of [O i ] <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>λ</mml:mi> <mml:mn>6300</mml:mn> </mml:math> emission disfavors the violent merger of two C/O white dwarfs (WDs) but the merger of a C/O WD with a He WD cannot be excluded. We compare our findings with several models in the literature postulated to explain the early flux excess including double-detonation explosions, 56 Ni mixing into the outer ejecta during ignition, and interaction with H- and He-deficient circumstellar material. Each model may be able to explain both the early flux excess and the nebular [Ca ii ] emission, but none of the models can reconcile the high photospheric velocities with the low peak luminosity without introducing new discrepancies.

Перевод пока недоступен

Идентификаторы

DOI: 10.3847/1538-4357/abf93b

Цитирования и источники

Цитирований: 2Использованных источников: 0

Показатели — AkademScholar