Abstract
The ejected mass distribution of Type Ia supernovae (SNe Ia) directly
probes progenitor evolutionary history and explosion mechanisms, with
implications for their use as cosmological probes. Although the
Chandrasekhar mass is a natural mass scale for the explosion of white
dwarfs as SNe Ia, models allowing SNe Ia to explode at other masses have
attracted much recent attention. Using an empirical relation between the
ejected mass and the light-curve width, we derive ejected masses
Mej and 56Ni masses MNi for a sample of
337 SNe Ia with redshifts z <0.7 used in recent cosmological
analyses. We use hierarchical Bayesian inference to reconstruct the
joint Mej-MNi distribution, accounting for
measurement errors. The inferred marginal distribution of Mej
has a long tail towards sub-Chandrasekhar masses, but cuts off sharply
above 1.4 M⊙. Our results imply that 25-50 per cent of
normal SNe Ia are inconsistent with Chandrasekhar-mass explosions, with
almost all of these being sub-Chandrasekhar mass;
super-Chandrasekhar-mass explosions make up no more than 1 per cent of
all spectroscopically normal SNe Ia. We interpret the SN Ia
width-luminosity relation as an underlying relation between
Mej and MNi, and show that the inferred relation
is not naturally explained by the predictions of any single known
explosion mechanism.
Original language | English |
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Pages (from-to) | 2535-2544 |
Number of pages | 10 |
Journal | Monthly Notices of the Royal Astronomical Society |
Volume | 445 |
Issue number | 3 |
Early online date | 20 Oct 2014 |
DOIs | |
Publication status | Published - 11 Dec 2014 |
Keywords
- methods: statistical
- supernovae: general
- white dwarfs
- dark energy