Radio transients from accretion-induced collapse of white dwarfs

TL;DR

This paper explores the radio emission and potential fast radio burst signals from accretion-induced collapse of white dwarfs, linking electromagnetic and gravitational wave observations to identify these events.

Contribution

It presents a detailed analysis of radio transients from AIC, including conditions for radio burst production and implications for future radio and gravitational wave surveys.

Findings

AIC can produce detectable radio synchrotron emission.

Supramassive neutron stars from AIC may emit fast radio bursts.

Radio transients from AIC could be correlated with gravitational wave signals.

Abstract

We investigate observational properties of accretion-induced collapse (AIC) of white dwarfs in radio frequencies. If AIC is triggered by accretion from a companion star, a dense circumstellar medium can be formed around the progenitor system. Then, the ejecta from AIC collide to the dense circumstellar medium, making a strong shock. The strong shock can produce synchrotron emission which can be observed in radio frequencies. Even if AIC occurs as a result of white dwarf mergers, we argue that AIC may cause fast radio bursts if a certain condition is satisfied. If AIC forms neutron stars which are so massive that rotation is required to support themselves (i.e., supramassive neutron stars), the supramassive neutron stars may immediately lose their rotational energy by the r-mode instability and collapse to black holes. If the collapsing supramassive neutron stars are strongly magnetized, they may emit fast radio bursts as previously suggested. The AIC radio transients from the single-degenerate systems may be detected in the future radio transient surveys like Very Large Array Sky Survey or the Square Kilometer Array transient survey. Because AIC is suggested to be a gravitational wave source, gravitational waves from AIC may be accompanied by radio-bright transients which can be used to confirm the AIC origin of observed gravitational waves.