We discuss application of population synthesis for binary stars to progenitors of SN Ia. We show that the only candidate systems able to support the rate of SNe Ia $\sim 10^{ -3} yr^{ -1}$ both in old and young populations are merging white dwarfs. In young populations ($\sim 1$ Gyr) edge-lit detonations in semidetached systems with nondegenerate helium star donors are also able to support a similar rate. The estimated current Galactic rate of SN Ia with single-degenerate progenitors is $\sim 10^{ -4} yr^{ -1}$.
Categories: astro-ph