Explosive Nucleosynthesis in Sub-Chandrasekhar mass Type Ia Supernovae: Dependence on Model Parameters

Shing-Chi Leung, Ken'ichi Nomoto

Published 2019-01-28Version 1

Recent observations of Type Ia supernovae (SNe Ia) have shown diversified properties of the explosion strength, light curves and chemical composition. To investigate possible origins of such diversities in SNe Ia, we have presented multi-dimensional hydrodynamical study of explosions and associated nucleosynthesis in the near Chandrasekhar mass carbon-oxygen (CO) white dwarfs (WDs) for wide parameters (Leung and Nomoto ApJ 861, 143, 2018). In the present paper, we extend our wide parameter survey of models to the explosions of sub-Chandrasekhar mass CO WDs. We take the double detonation model for the explosion mechanism. The model parameters of the survey include metallicity of $Z = 0 - 5$ $Z_\odot$, the mass of the CO WD progenitor of $M = 0.90 - 1.20$ $M_\odot$, the He envelope mass of $M_{\rm He} = 0.05 - 0.20$ $M_\odot$. We also study how the initial He detonation configuration affects the triggering of the C detonation. For these parameters, we first derive the minimum He envelope mass necessary to trigger the C detonation. We then examine how the explosion dynamics and associated nucleosynthesis depend on these parameters, and compare our results with the previous representative models. We compare our nucleosynthesis yields with the unusual abundance patterns of Fe-peak elements and isotopes observed in SNe Ia 2011fe, 2012cg, 2014J, and SN Ia remnant 3C 397 to provide constraints on their progenitors and environments. We provide the nucleosynthesis yields table of the sub-Chandrasekhar mass explosions, to discuss their roles in the galactic chemical evolution and archaeology.