On measuring the metallicity of a type ia supernova's progenitor

Journal Article · Fri Jun 10 04:00:00 EDT 2016 · Astrophysical Journal

DOI:https://doi.org/10.3847/0004-637X/824/1/59· OSTI ID:22868995

Miles, Broxton J.; Townsley, Dean M. ^[1]; Rossum, Daniel R. van ^[2]; Timmes, F. X.; Brown, Edward F. ^[3]; Jackson, Aaron P.

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1. Department of Physics and Astronomy, University of Alabama, Tuscaloosa, AL (United States)
2. Department of Astrophysics, The University of Chicago, Chicago, IL (United States)
3. The Joint Institute for Nuclear Astrophysics (United States)

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 {sup 56}Ni 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, {sup 28}Si yields remain nearly constant, {sup 40}Ca yields decline, and Ti and {sup 54}Fe 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 Å and an Fe feature around 5200 Å. 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.

• OSTI ID: 22868995
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 824; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ABUNDANCE
CALCIUM 40
COMPUTERIZED SIMULATION
CORRELATIONS
EXPLOSIONS
IRON 54
MASS
METALLICITY
NEUTRONS
NICKEL 56
NUCLEAR REACTIONS
NUCLEOSYNTHESIS
RADIANT HEAT TRANSFER
SILICON 28
SPECTRA
TWO-DIMENSIONAL CALCULATIONS
TWO-DIMENSIONAL SYSTEMS
TYPE I SUPERNOVAE
WHITE DWARF STARS