Detecting eclipsing double white dwarfs with electromagnetic and gravitational waves

TL;DR

This study predicts the detection capabilities of upcoming gravitational wave and electromagnetic observatories for double white dwarf systems, highlighting the potential for joint multi-messenger observations to enhance understanding of these sources.

Contribution

The paper introduces simulations of double white dwarf populations from different star formation histories and evaluates their detectability via multiple current and future observatories, including joint electromagnetic and gravitational wave detection.

Findings

TianQin and LISA can detect over 5,000 double white dwarfs individually.

Gaia and VRO can detect dozens to hundreds of eclipsing double white dwarfs.

Joint electromagnetic and gravitational wave observations can identify several dozen systems.

Abstract

Galactic double white dwarfs are predominant sources of gravitational waves in the millihertz frequencies accessible to space-borne gravitational wave detectors. With advances in multi-messenger astronomy, an increasing number of double white dwarf systems will be discovered through both electromagnetic and gravitational wave observations. In this paper, we simulated two populations of double white dwarfs originating from different star formation histories (hereafter referred to as Model 1 and Model 2) using the binary population synthesis method. We predicted the number of double white dwarfs in our Galaxy detectable by TianQin and Laser Interferometer Space Antenna (LISA) individually, as well as through their joint observation. In addition, we performed an analysis to evaluate the accuracy of the parameter estimation using the Fisher information matrix. Furthermore, we predicted the number of detached eclipsing double white dwarfs detectable by Gaia and the Vera C. Rubin Observatory (VRO). Our study found that over the nominal mission durations, TianQin, LISA, and their joint observation can detect at least five thousand and potentially several tens of thousands of double white dwarfs with signal-to-noise ratios greater than 7. Gaia and VRO are expected to detect at least several dozen and up to several hundred eclipsing double white dwarfs with orbital periods less than 30 hours. We also found that several dozen eclipsing double white dwarfs can be detected jointly through electromagnetic and gravitational wave observations.