Type Ia supernova ejecta-donor interaction: explosion model comparison

Abstract

In the single-degenerate scenario of Type Ia supernovae (SNe Ia), the interaction between high-speed ejected material and the donor star in a binary system is expected to lead to mass being stripped from the donor. A series of multi-dimensional hydrodynamical simulations of ejecta-donor interaction have been performed in previous studies most of which adopt either a simplified analytical model or the W7 model to represent a normal SN Ia explosion. Whether different explosion mechanisms can significantly affect the results of ejecta-donor interaction is still unclear. In this work, we simulate hydrodynamical ejecta interactions with a main-sequence (MS) donor star in two dimensions for two near-Chandrasekhar-mass explosion models of SNe Ia, the W7 and N100 models. We find that about 0.30 and 0.37 Msun of hydrogen-rich material are stripped from a 2.5 Msun donor star in a 2 day orbit by the SN Ia explosion in simulations with the W7 deflagration and N100 delayed-detonation explosion model, respectively. The donor star receives a kick of about 74 and 86 km/s, respectively, in each case. The modal velocity, about 500 km/s, of stripped hydrogen-rich material in the N100 model is faster than the W7 model, with modal velocity of about 350km/s, by a factor 1.4. Based on our results, we conclude that the choice of near-Chandrasekhar-mass explosion model for normal SNe Ia seems to not significantly alter the ejecta-donor interaction for a given main-sequence donor model, at least in 2D.