On Silicon Group Elements Ejected By Supernovae Type IA

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dc.contributor.author De, Soma
dc.contributor.author Timmes, F. X.
dc.contributor.author Brown, Edward M.
dc.contributor.author Calder, Alan C.
dc.contributor.author Townsley, Dean M.
dc.contributor.author Athanassiadou, Themis
dc.contributor.author Chamulak, David A.
dc.contributor.author Hawley, Wendy
dc.contributor.author Jack, Dennis
dc.date.accessioned 2018-08-23T19:58:10Z
dc.date.available 2018-08-23T19:58:10Z
dc.date.issued 2014-06-01
dc.identifier.citation De, Soma., et al. (2014): On Silicon Group Elements Ejected by Supernovae Type Ia. The Astrophysical Journal, 787(2). en_US
dc.identifier.uri http://ir.ua.edu/handle/123456789/3761
dc.description.abstract There is evidence that the peak brightness of a Type Ia supernova is affected by the electron fraction Ye at the time of the explosion. The electron fraction is set by the aboriginal composition of the white dwarf and the reactions that occur during the pre-explosive convective burning. To date, determining the makeup of the white dwarf progenitor has relied on indirect proxies, such as the average metallicity of the host stellar population. In this paper, we present analytical calculations supporting the idea that the electron fraction of the progenitor systematically influences the nucleosynthesis of silicon group ejecta in Type Ia supernovae. In particular, we suggest the abundances generated in quasi-nuclear statistical equilibrium are preserved during the subsequent freeze-out. This allows potential recovery of Ye at explosion from the abundances recovered from an observed spectra. We show that measurement of 28Si, 32S, 40Ca, and 54Fe abundances can be used to construct Ye in the silicon-rich regions of the supernovae. If these four abundances are determined exactly, they are sufficient to recover Ye to 6%. This is because these isotopes dominate the composition of silicon-rich material and iron-rich material in quasi-nuclear statistical equilibrium. Analytical analysis shows the 28Si abundance is insensitive to Ye, the 32S abundance has a nearly linear trend with Ye, and the 40Ca abundance has a nearly quadratic trend with Ye. We verify these trends with post-processing of one-dimensional models and show that these trends are reflected in the model’s synthetic spectra. en_US
dc.format.mimetype application/pdf en_US
dc.subject nuclear reactions, nucleosynthesis, abundances en_US
dc.subject supernovae: general en_US
dc.subject white dwarfs en_US
dc.title On Silicon Group Elements Ejected By Supernovae Type IA en_US
dc.type text en_US

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