Maqola

SN 2019ein: a Type Ia supernova likely originated from a sub-Chandrasekhar-mass explosion

Gaobo XiPhysics Department and Tsinghua Center for Astrophysics, Tsinghua University , Beijing 100084, ChinaXiaofeng WangBeijing Planetarium, Beijing Academy of Science and Technology , Beijing 100044, ChinaWenxiong LiThe School of Physics and Astronomy, Tel Aviv University , Tel Aviv 69978, IsraelJun MoPhysics Department and Tsinghua Center for Astrophysics, Tsinghua University , Beijing 100084, ChinaJujia ZhangCenter for Astronomical Mega-Science, Chinese Academy of Sciences , 20A Datun Road, Chaoyang District, Beijing 100012, ChinaJialian LiuPhysics Department and Tsinghua Center for Astrophysics, Tsinghua University , Beijing 100084, ChinaZhihao ChenPhysics Department and Tsinghua Center for Astrophysics, Tsinghua University , Beijing 100084, ChinaA. V. FilippenkoDepartment of Astronomy, University of California , Berkeley, CA 94720-3411, USAWeiKang ZhengDepartment of Astronomy, University of California , Berkeley, CA 94720-3411, USAThomas G. BrinkDepartment of Astronomy, University of California , Berkeley, CA 94720-3411, USAXinghan ZhangPhysics Department and Tsinghua Center for Astrophysics, Tsinghua University , Beijing 100084, ChinaHanna SaiPhysics Department and Tsinghua Center for Astrophysics, Tsinghua University , Beijing 100084, ChinaSh. A. EhgamberdievDepartment of Astronomy and Astrophysics, Physics Faculty, National University of Uzbekistan , Tashkent 100174, UzbekistanD. O. MirzaqulovUlugh Beg Astronomical Institute, Uzbekistan Academy of Sciences , Tashkent 100052, UzbekistanJicheng ZhangCenter for Astronomical Mega-Science, Chinese Academy of Sciences , 20A Datun Road, Chaoyang District, Beijing 100012, China

Monthly Notices of the Royal Astronomical Societyjournal2022en

ABI

Annotatsiya

ABSTRACT We present extensive optical photometric and spectroscopic observations for the nearby Type Ia supernova (SN Ia) 2019ein, spanning the phases from ∼3 to ∼330 d after the explosion. This SN Ia is characterized by extremely fast expansion at early times, with initial velocities of Si ii and Ca ii being above ∼25 000–30 000 km s−1. After experiencing an unusually rapid velocity decay, the ejecta velocity dropped to ∼13 000 km s−1 around maximum light. Photometrically, SN 2019ein has a moderate post-peak decline rate (Δm15(B) = 1.35 ± 0.01 mag), while being fainter than normal SNe Ia by about 40 per cent (with $M^{\rm max}_{B} \approx -18.71 \pm 0.15$ mag). The nickel mass synthesized in the explosion is estimated to be 0.27–0.31 M⊙ from the bolometric light curve. Given such a low nickel mass and a relatively high photospheric velocity, we propose that SN 2019ein likely had a sub-Chandrasekhar-mass white dwarf (WD) progenitor, MWD ≲ 1.22 M⊙. In this case, the explosion could have been triggered by a double-detonation mechanism, for which 1D and 2D models with WD mass MWD ≈ 1 M⊙ and a helium shell of 0.01 M⊙ can reasonably produce the observed bolometric light curve and spectra. The predicted asymmetry as a result of double detonation is also favoured by the redshifted Fe ii and Ni ii lines observed in the nebular-phase spectrum. Possible diversity in origin of high velocity SNe Ia is also discussed.

Mavzular

Gamma-ray bursts and supernovae Astrophysical Phenomena and Observations Neutrino Physics Research

Identifikatorlar

DOI: 10.1093/mnras/stac2848

Iqtiboslar va manbalar

1 ta iqtibos 152 ta foydalanilgan manba

Koʻrsatkichlar — AkademScholar · Tez orada