Binary population synthesis for the core-degenerate scenario of type Ia supernova progenitors

The core-degenerate（CD） scenario has been suggested to be a possible progenitor model of type Ia supernovae（SNe Ia）,in which a carbon-oxygen white dwarf merges with the hot CO core of a massive asymptotic giant branch star during their common-envelope phase.However,the SN Ia birthrates for this scenario are still uncertain.We conducted a detailed investigation into the CD scenario and then gave the birthrates for this scenario using a detailed Monte Carlo binary population synthesis approach.We found that the delay times of SNe Ia from this scenario are;0 Myr-1400 Myr,which means that the CD scenario contributes to young SN la populations.The Galactic SN la birthrates for this scenario are in the range of;.4×10;yr;- 3.7 × 10;yr;,which roughly accounts for;%-10%of all SNe Ia.This indicates that,under the assumptions made here,the CD scenario only contributes a small portion of all SNe Ia,which is not consistent with the results of Ilkov & Soker.