The single-degenerate model for the progenitors of accretion-induced collapse events

TL;DR

This paper systematically studies the single-degenerate progenitor models for accretion-induced collapse, including various binary channels, and estimates their rates and delay times, highlighting the significance of the ONe WD+He star channel.

Contribution

It provides a comprehensive analysis of the SD model for AIC, incorporating multiple channels and detailed binary evolution calculations.

Findings

AIC rates in the galaxy are approximately 0.3-0.9 x 10^{-3} per year.

Delay times for AIC events are greater than 30 million years.

The ONe WD+He star channel is the dominant progenitor pathway.

Abstract

It has been suggested that the accretion-induced collapse (AIC) of an oxygen-neon white dwarf (ONe WD) to a neutron star is a theoretically predicted outcome in stellar evolution, likely relating to the formation of some neutron star systems. However, the progenitor models of AIC events are still not well studied, and recent studies indicated that CO WD+He star systems may also contribute to the formation of neutron star systems through AIC process when off-centre carbon ignition happens on the surface of the CO WD. In this work, I studied the single-degenerate (SD) model of AIC events in a systematic way, including the contribution of the CO WD+He star channel and the ONe WD+MS/RG/He star channels. Firstly, I gave the initial parameter space of these SD channels for producing AIC events in the orbital period--secondary mass plane based on detailed binary evolution computations. Then, according to a binary population synthesis approach, I gave the rates and delay times of AIC events for these SD channels based on their initial parameter space. I found that the rates of AIC events in our galaxy are in the range of $\sim0.3-0.9\times10^{-3}$\,yr$^{-1}$,and that their delay times are $>$30\,Myr. I also found that the ONe WD+He star channel is the main way to produce AIC events, and that the CO WD+He star channel cannot be ignored when studying the progenitors of AIC events.