A very low central oxygen mass in the peculiar type Ia SN 2010lp: further diversity at the low-luminosity end of SNe Ia. Issue 4 (16th February 2022)

• Record Type: Journal Article
• Authors: Mazzali, P A; Benetti, S; Stritzinger, M; Ashall, C
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 511:Issue 4(2022)
• Page Start: 5560
• Page End: 5569
• Publication Date: 2022-02-16
• Subjects: radiative transfer -- techniques: spectroscopic -- supernovae: general -- supernovae: individual (SN 2010lp); Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stac409
• Languages: English
• ISSNs: 0035-8711

Abstract

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.