A very low central oxygen mass in the peculiar type Ia SN 2010lp: further diversity at the low-luminosity end of SNe Ia
Abstract
A nebular spectrum of the peculiar, low-luminosity type Ia supernova 2010lp is modelled in order to estimate the composition of the inner ejecta and to illuminate the nature of this event. Despite having a normally declining light curve, SN 2010lp was similar spectroscopically to SN 1991bg at early times. However, it showed a very unusual double-peaked [O I] $\lambda \lambda \, 6300,6363$ emission at late times (Taubenberger et al.). Modelling of the nebular spectrum suggests that a very small amount of oxygen (~0.05 M⊙), expanding at very low speed (≲ 2000 km s-1) is sufficient to reproduce the observed emission. The rest of the nebula is not too dissimilar from SN 1991bg, except that SN 2010lp is slightly more luminous. The double-peaked [O I] emission suggests that SN 2010lp may be consistent with the merger or collision of two low-mass white dwarfs. The low end of the SN Ia luminosity sequence is clearly populated by diverse events, where different channels may contribute.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- April 2022
- DOI:
- 10.1093/mnras/stac409
- arXiv:
- arXiv:2202.04636
- Bibcode:
- 2022MNRAS.511.5560M
- Keywords:
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- radiative transfer;
- techniques: spectroscopic;
- supernovae: general;
- supernovae: individual (SN 2010lp);
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- Accepted for publication in MNRAS