The contribution of Type IA supernovae to the galactic iron abundances

Abstract

The thermonuclear explosion of a mass-accreting white dwarf in a close binary system is thought to be at the origin of Type Ia supernovae. Standard models, which ignite carbon at densities higher than 2-4 x 10 exp 9 g/cu cm, give, however, a large production of species like Fe-54, Ni-58, and Cr-54, which has been regarded as incompatible with the solar system abundances. In this paper we analyze the weight of the constraints imposed by nucleosynthesis of the Fe-peak nuclides to the aforementioned scenario for Type Ia supernovae when the contribution of Type II and Type Ib supernovae to the galactic iron abundances is also taken into account. We find that the production of the aforementioned nuclides predicted by standard SNIa models is in fact compatible with the solar system abundances when the yields from gravitational-collapse supernovae are adjusted to reproduce the Ni abundances in low-metallicity stars.