The GALEX-Gaia-EDR3 Catalogue of Single and Binary White Dwarfs

Abstract: We present a catalogue of white dwarf candidates constructed from the GALEX and Gaia EDR3 catalogues. The catalogue contains 332,111 candidate binary white dwarf systems and 111,996 candidate single white dwarfs. Where available, the catalogue is augmented with photometry from Pan-STARRS DR1, SDSS DR12 and classifications from StarHorse. We fit photometric data with modeled white dwarf cooling sequences to derive mass, age and effective temperature of the white dwarf as well as mass estimates for the companion. We test our classifications against StarHorse, the Gentile-Fusillo Gaia EDR3 catalogue, and white-dwarf-main-sequence binaries identified in SDSS DR12. This catalogue provides a unique probe of the binarity of white dwarfs as well as the abundance of white-dwarf giant binaries and large mass-ratio stellar binaries which are difficult to probe otherwise.