Models for Type I supernovae - Partially incinerated white dwarfs

Abstract

White dwarf models are calculated for the explosions and light curves of Type I supernovae using full hydrodynamics and radiative diffusion. Comparison is made to recent observations. The models are based on the instantaneous thermonuclear burning of part or all of a degenerate carbon/oxygen/helium core. The Rayleigh-Taylor instability at the points of density/composition discontinuity is explored. The effects of radioactive decay of <SUP>56</SUP>Ni and <SUP>56</SUP>Co are incorporated by means of an absorption treatment of γ-rays. It is concluded that despite the qualitative appeal of the picture in which binary mass accretion raises a carbon-oxygen white dwarf to the Chandrasekhar limit, the demand to produce supernovae of the observed characteristics is not easily reconciled quantitatively with current calculations of hydrogen accretion.