Accreting white dwarf models for the type I supernovae. IV The optical spectrum of a carbon-deflagration supernova

Abstract

Theoretical optical spectra for a carbon-deflagration model of a Type I supernova are computed and compared to spectra of supernova 1981b in NGC 4536 observed at the time of maximum light and 17 days later. If the radial stratification of the composition in the outer layers of the supernova model is assumed to be removed by mixing, the theoretical and observed spectra are in good agreement; the discrepancies could be due to the approximations in the synthetic-spectrum calculations. Spectra for the carbon deflagration model in its unmixed form appear to be inconsistent with observation.