2010ApJ...710.1310M

Although the nature of the progenitor of Type Ia supernovae (SNe Ia) is still unclear, the single-degenerate (SD) channel for the progenitor is currently accepted, in which a carbon-oxygen white dwarf (CO WD) accretes hydrogen-rich material from its companion, increases its mass to the Chandrasekhar mass limit, and then explodes as an SN Ia. The companion may be a main sequence or a slightly evolved star (WD + MS), or a red giant star (WD + RG). Incorporating the effect of mass stripping and accretion-disk instability on the evolution of the WD binary, we carried out binary stellar evolution calculations for more than 1600 close WD binaries. As a result, the initial parameter spaces for SNe Ia are presented in an orbital period-secondary mass (log P_i, M ⁱ₂) plane. We confirmed that in a WD + MS system, the initial companion leading to SNe Ia may have mass from 1 M_☉ to 5 M_☉. The initial WD mass for SNe Ia from WD + MS channel is as low as 0.565 M_☉, while the lowest WD mass from the WD + RG channel is 1.0 M_☉. Adopting the above results, we studied the birth rate of SNe Ia via a binary population synthesis approach. We found that the Galactic SNe Ia birth rate from SD model is (2.55-2.9)x10^–3/yr (including WD + He star channel), which is slightly smaller than that from observation. If a single starburst is assumed, the distribution of the delay time of SNe Ia from the SD model may be a weak bimodality, where WD + He channel contributes to SNe Ia with delay time shorter than 10⁸ yr and WD + RG channel to those with age longer than 6 Gyr.