Progenitors of the Accretion-Induced Collapse of White Dwarfs

Abstract

Recent calculations of accretion-induced collapse of an oxygen-neon-magnesium white dwarf into a neutron star [Piro & Thompson 2014] allow for a potentially detectable transient electromagnetic signal. Motivated by these results, I present theoretical rates and physical properties of binary stars that can produce accretion-induced collapse. The rates are presented for various types of host galaxies (e.g. old ellipticals versus spirals) and are differentiated by the donor star type (e.g. large giant star versus compact helium-rich donor). Results presented in this thesis may help to guide near-future electromagnetic transient search campaigns to find likely candidates for accretion-induced collapse events. My predictions are based on binary evolution calculations that include the most recent updates on mass accretion and secular mass growth of white dwarfs. I find that the most likely systems that undergo accretion-induced collapse consist of an ONeMg white dwarf with a Hertzsprung gap star or a red giant companion. Typical rates are of the order ~1-5 x 10^-5 1/yr and ~10^-4-10^-5 1/yr in large spiral galaxies and old ellipticals, respectively. The brightest electromagnetic signals are predicted for evolved giant type donors for which I find rates of the order ~2.5 x 10^-5 1/yr (large spirals) and ~1.3 x 10^-5 1/yr (old ellipticals).