Super-Eddington wind scenario for the progenitors of type Ia supernovae: binary population synthesis calculations

¹ Yunnan Observatories, Chinese Academy of Sciences, 650026 Kunming, PR China
e-mail: wangbo@ynao.ac.cn
² Key Laboratory for the Structure and Evolution of Celestial Objects, Chinese Academy of Sciences, 650026 Kunming, PR China
³ Argelander-Institut für Astronomie, Auf dem Hügel 71, 53121 Bonn, Germany

Received: 7 November 2014
Accepted: 23 February 2015

Abstract

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 ~0.009−0.315 × 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.