Explosive Nucleosynthesis in Near-Chandrasekhar Mass White Dwarf Models for Type Ia Supernovae: Dependence on Model Parameters [SSA]


We present two-dimensional hydrodynamics simulations of near-Chandrasekhar mass white dwarf (WD) models for Type Ia supernovae (SNe Ia) using the turbulent deflagration model with deflagration-detonation transition. By calculating 45 models, we perform a parameter survey to study the effects of the initial central density (i.e., WD mass), metallicity, flame shape and detonation transition criteria, and turbulent flame formula for a much wider parameter space than earlier studies. The final isotopic abundances of $^{11}$C to $^{91}$Tc in these simulations are obtained by post-process nucleosynthesis calculation. The survey includes SNe Ia models with the central density from $5 \times 10^8$ g cm$^{-3}$ to $5 \times 10^9$ g cm$^{-3}$ (WD masses of 1.30 – 1.38 $M_\odot$), metallicity from 0 to 5 $Z_{\odot}$, C/O mass ratio from 0.3 – 1.0 and ignition kernels including centered and off-centered ignition kernels. The yield tables of 25 isotopes from carbon to zinc for a total of 45 models are computed. Observational abundances of $^{55}$Mn, $^{56}$Fe, $^{57}$Fe and $^{58}$Ni obtained from the solar composition, well-observed SNe Ia and SN Ia remnants are used to constrain the explosion models and the supernova progenitor. The connection between the pure turbulent deflagration model and the subluminous SNe Iax is discussed. We find that dependencies of the nucleosynthesis yields on the metallicity and the central density (WD mass) are large. For comparisons with the observed abundance patterns of SNe Ia and their remnants to constrain the explosion model and also for the application to the galactic chemical evolution modeling, these dependencies on the metallicity and WD mass should be taken into account. For this purpose, we present tables of the nucleosynthesis yields of $^{12}$C to $^{70}$Zn as well as the major radioactive isotopes for 24 models.

Read this paper on arXiv…

S. Leung and K. Nomoto
Fri, 13 Oct 17

Comments: 29 pages, 29 figures. Submitted to Astrophysical Journal Supplement