ON MEASURING the METALLICITY of A TYPE IA SUPERNOVA'S PROGENITOR

Broxton J. Miles, Daniel R Van Rossum, Dean M. Townsley, Francis Timmes, Aaron P. Jackson, Alan C. Calder, Edward F. Brown

Research output: Contribution to journalArticle

13 Scopus citations

Abstract

In Type Ia Supernovae (SNe Ia) the relative abundances of chemical elements are affected by the neutron excess in the composition of the progenitor white dwarf. Since these products leave signatures in the spectra near maximum light, spectral features may be used to constrain the composition of the progenitor. We calculate the nucleosynthetic yields for three SN Ia simulations, assuming single degenerate, Chandrasekhar-mass progenitors, for a wide range of progenitor metallicities, and calculate synthetic light curves and spectra to explore correlations between progenitor metallicity and the strength of spectral features. We use two two-dimensional simulations of the deflagration-detonation-transition scenario with different 56Ni yields and the W7 simulation to control for differences between explosion models and total yields. While the overall yields of intermediate-mass elements (16 < A 40) differ between the three cases, trends in the yields are similar. With increasing metallicity, 28Si yields remain nearly constant, 40Ca yields decline, and Ti and 54Fe yields increase. In the synthetic spectra, we identify two features at 30 days post-explosion that appear to deepen with progenitor metallicity: a Ti feature around 4200 and an Fe feature around 5200. In all three simulations, their pseudo equivalent widths show a systematic trend with progenitor metallicity. This suggests that these two features may allow for differentiation among progenitor metallicities of observed SNe Ia and potentially help to reduce the intrinsic Hubble scatter.

Original languageEnglish (US)
Article number59
JournalAstrophysical Journal
Volume824
Issue number1
DOIs
StatePublished - Jun 10 2016

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Keywords

  • nuclear reactions, nucleosynthesis, abundances
  • radiative transfer
  • stars: abundances
  • supernovae: general

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Miles, B. J., Rossum, D. R. V., Townsley, D. M., Timmes, F., Jackson, A. P., Calder, A. C., & Brown, E. F. (2016). ON MEASURING the METALLICITY of A TYPE IA SUPERNOVA'S PROGENITOR. Astrophysical Journal, 824(1), [59]. https://doi.org/10.3847/0004-637X/824/1/59