# Prospects for detection of detached double white dwarf binaries with Gaia, LSST and LISA

## TL;DR

This paper assesses the detection prospects of detached double white dwarf binaries using Gaia, LSST, and LISA, highlighting their potential to significantly expand known samples and enable multi-messenger astronomy.

## Contribution

It provides the first comprehensive analysis of detection capabilities of Gaia, LSST, and LISA for ultra-compact DWDs, emphasizing their combined potential.

## Key findings

- Gaia could detect hundreds of DWDs in optical data.
- LSST could identify around a thousand DWDs.
- LISA may detect approximately 25,000 DWD systems.

## Abstract

Double white dwarf (DWD) binaries are expected to be very common in the Milky Way, but their intrinsic faintness challenges the detection of these systems. Currently, only a few tens of detached DWDs are know. Such systems offer the best chance of extracting the physical properties that would allow us to address a wealth of outstanding questions ranging from the nature of white dwarfs, over stellar and binary evolution to mapping the Galaxy. In this paper we explore the prospects for detections of ultra-compact (with binary separations of a few solar radii or less) detached DWDs in: 1) optical radiation with Gaia and the LSST and 2) gravitational wave radiation with LISA. We show that Gaia, LSST and LISA have the potential to detect respectively around a few hundreds, a thousand, and 25 thousand DWD systems. Moreover, Gaia and LSST data will extend by respectively a factor of two and seven the guaranteed sample of binaries detected in electromagnetic and gravitational wave radiation, opening the era of multi-messenger astronomy for these sources.