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abstract: 'The metallicity of a star strongly effects both its evolution and the properties of the stellar remnant that results from its demise. It is generally accepted that stars with initial masses below $\sim 8\,M_\odot$ leave behind white dwarfs and that some sub-population of these lead to Type Ia supernovae. However, it is often tacitly assumed that metallicity has no effect on the rate of SNe Ia. We propose that a natural consequence of the effects of metallicity is to significantly increase the SN Ia rate in lower-metallicity galaxies. This is because lower-metallicity stars leave behind higher-mass white dwarfs, which should generally be easier to bring to an explosion. Using a simple model to relate the SN rate to galaxy age and metallicity, we find that the elevation in the rate of SNe Ia in lower-mass galaxies measured by LOSS is readily explained. We also find that models using the same parameters agree well with cosmic SN Ia rates up to $z\approx2$. We discuss additional implications of metallicity, including for inferences of the SN Ia delay time distribution and super-Chandrasekhar SNe.'
author:
- 'Matthew D. Kistler, K. Z. Stanek, Christopher S. Kochanek, Jos[é]{} L. Prieto, and Todd A. Thompson'
