Speaker
Suhail Dhawan
Description
Fast-declining Type Ia supernovae (SN Ia) separate into
two
categories based on their bolometric and near-infrared
(NIR)
properties. The peak bolometric luminosity
(Lmax), the phase of the first maximum
relative
to the optical, the NIR peak luminosity and the occurrence
of a second maximum in the NIR distinguish a group of
very
faint SN Ia. Fast-declining supernovae show a large range
of
peak bolometric luminosities (Lmax differing
by
up to a factor of ~8). All fast-declining SN Ia with
Lmax<0.3⋅ 10^43 ergs^−1 are
spectroscopically
classified as 91bg-like and show only a single NIR peak.
SNe
with Lmax>0.5⋅
10^43 ergs^−1 appear to smoothly connect
to normal SN Ia. The total ejecta mass (M_ej)
values for SNe with enough late time data are ≲1 M⊙,
indicating a sub-Chandrasekhar mass progenitor for these
SNe.
