The Impact of Metallicity on the Rate of Type Ia Supernovae
Abstract
The metallicity of a star strongly affects 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 ~8 M_☉ leave behind white dwarfs and that some sub-population of these lead to Type Ia supernovae (SNe Ia). However, it is often tacitly assumed that metallicity has no effect on the rate of SNe Ia. We propose that a consequence of the effects of metallicity is to significantly increase the SN Ia rate in lower-metallicity galaxies, in contrast to previous expectations. This is because lower-metallicity stars leave behind higher-mass white dwarfs, which should be easier to bring to explosion. We first model SN Ia rates in relation to galaxy masses and ages alone, finding that the elevation in the rate of SNe Ia in lower-mass galaxies measured by Lick Observatory SN Search is readily explained. However, we then see that models incorporating this effect of metallicity agree just as well. Using the same parameters to estimate the cosmic SN Ia rate, we again find good agreement with data up to z ≈ 2. We suggest that this degeneracy warrants more detailed examination of host galaxy metallicities. We discuss additional implications, including for hosts of high-z SNe Ia, the SN Ia delay time distribution, super-Chandrasekhar SNe, and cosmology.
Additional Information
© 2013 American Astronomical Society. Received 2012 August 3; accepted 2013 April 30; published 2013 May 28. We thank John Beacom, Jonathan Bird, Shunsaku Horiuchi, Rubab Khan, Marc Pinsonneault, and Hasan Yuksel for helpful discussions, Weidong Li for providing us with the data in Figure 1, and the referee for helpful comments. M.D.K. acknowledges support provided by NASA through the Einstein Fellowship Program, grant PF0-110074. K.Z.S., C.S.K. and T.A.T. are supported in part by NSF grant AST-0908816. J.L.P. acknowledges support from NASA through Hubble Fellowship grant HF-51261.01-A awarded by the STScI, which is operated by AURA, Inc. for NASA, under contract NAS 5-26555. T.A.T. is supported in part by an Alfred P. Sloan Foundation Fellowship.Attached Files
Published - 0004-637X_770_2_88.pdf
Submitted - 1106.3115v2.pdf
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Additional details
- Eprint ID
- 39541
- Resolver ID
- CaltechAUTHORS:20130723-150039543
- PF0-110074
- NASA Einstein Fellowship
- AST-0908816
- NSF
- HF-51261.01-A
- NASA Hubble Fellowship
- NAS 5-26555
- NASA
- Alfred P. Sloan Foundation
- Created
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2013-07-23Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field