Measuring mass transfer of AM CVn binaries with a space-based gravitational wave detector

TL;DR

This paper demonstrates that future space-based gravitational wave detectors can accurately measure the mass transfer rates of AM CVn binaries, significantly advancing understanding of their formation mechanisms beyond electromagnetic methods.

Contribution

It introduces a Fisher analysis method using a post-Keplerian waveform model to estimate mass transfer rates from gravitational wave signals, focusing on Gaia DR2 sources.

Findings

Gravitational wave detection can measure mass transfer rates with high accuracy.

GW measurements improve accuracy over electromagnetic methods by over two orders of magnitude.

Results support GW detection as a powerful tool for studying AM CVn binary formation.

Abstract

The formation mechanism of AM CVn binary has not been well understood yet. Accurate measurements of the mass transfer rate can help to determine the formation mechanism. But unfortunately such observation by electromagnetic means is quite challenging. One possible formation channel of AM CVn binary is a semi-detached white dwarf binary. Such system emits strong gravitational wave radiation which could be measured by the future space-based detectors. We can simultaneously extract the mass transfer rate and the orbital period from the gravitational wave signal. We employ a post-Keplerian waveform model of gravitational wave and carry out a Fisher analysis to estimate the measurement accuracy of mass transfer rate through gravitational wave detection. Special attention is paid to the observed sources in Gaia Data Release 2. We found that we can accurately measure the mass transfer rate for those systems. Comparing to electromagnetic observations, gravitational wave detection improves the accuracy more than two orders of magnitude. Our results imply that the gravitational wave detection will help much in understanding the formation mechanism of AM CVn binaries.