大样本恒星演化研究组知识库

Context. The super-Eddington wind scenario has been proposed as an alternative way for producing type Ia supernovae (SNe Ia). The super-Eddington wind can naturally prevent the carbon-oxygen white dwarfs (CO WDs) with high mass-accretion rates from becoming red-giant-like stars. Furthermore, it works in low-metallicity environments, which may explain SNe Ia observed at high redshifts. 

Aims. In this article, we systematically investigated the most prominent single-degenerate WD+ MS channel based on the super-Eddington wind scenario. 

Methods. We combined the Eggleton stellar evolution code with a rapid binary population synthesis (BPS) approach to predict SN Ia birthrates for the WD+ MS channel by adopting the super-Eddington wind scenario and detailed mass-accumulation efficiencies of H-shell flashes on the WDs. 

Results. Our BPS calculations found that the estimated SN Ia birthrates for the WD+ MS channel are similar to 0.009-0.315 x 10(-3) yr(-1) if we adopt the Eddington accretion rate as the critical accretion rate. These rates are much lower than those of the observations (< 10% of the observed SN Ia birthrates). This indicates that the WD+ MS channel only contributes a small portion of all SNe Ia. The birthrates in this simulation are lower than those of previous studies, the main reason for which is that new mass-accumulation efficiencies of H-shell flashes are adopted. We also found that the critical mass-accretion rate has significant influence on the birthrates of SNe Ia. Meanwhile, the results of our BPS calculations are sensitive to the values of the common-envelope ejection efficiency.