Open AccessCircumstellar interaction of the type Ia supernova 2002ic
Author(s) -
Chugai N. N.,
Chevalier R. A.,
Lundqvist P.
Publication year - 2004
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2004.08347.x
Subject(s) - physics , ejecta , astrophysics , supernova , light curve , circumstellar envelope , flux (metallurgy) , stars , materials science , metallurgy
We propose a model to account for the bolometric light curve, the quasi‐continuum and the Ca ii emission features of the peculiar type Ia supernova (SN) 2002ic, which exploded in a dense circumstellar envelope. The model suggests that the SN Ia had the maximum possible kinetic energy and that the ejecta expand in an approximately spherically symmetric (possibly clumpy) circumstellar environment. The Ca ii and the quasi‐continuum are emitted by shocked SN ejecta that underwent deformation and fragmentation in the intershock layer. Modelling of the Ca ii triplet implies that the contribution of the O i 8446‐Å line is about 25 per cent of the 8500‐Å feature on day 234, which permits us to recover the flux in the Ca ii 8579‐Å triplet from the flux of 8500‐Å blend reported by Deng et al. We use the Ca ii doublet and triplet fluxes on day 234 to derive the electron temperature (≈ 4400 K) in the Ca ii line‐emitting zone and the ratio of the total area of dense fragments to the area of the shell, S / S 0 ∼ 10 2 . We argue that Ca ii bands and the quasi‐continuum originate from different zones of the shocked ejecta that reflect the abundance stratification of the supernova.