Searching for new cataclysmic variables in different X-ray and optical catalogs

Abstract

Cataclysmic variables (CVs) are binary systems in which a white dwarf accretes matter from a Roche-lobe-filling companion star. Numerous CVs can be seen in optical light curves as periodic sources. Moreover, accretion can result in outbursts, which are visible in their optical light curves, especially in non-magnetic CVs. I review a modern multiwavelength approach to classifying new CVs among stellar objects based on an X-ray main sequence, a phase space of X-ray-to-optical flux ratio, and a Gaia optical (BP–RP) color. Using this method, it is possible to identify a dozen new CV candidates in a cross-match of different X-ray catalogs, Gaia proper motion data, and the optical Zwicky Transient Facility database. I discuss the recently discovered new magnetic and non-magnetic CVs, including an eclipsing AM CVn and the period-bouncer CV. These results show that a multiwavelength approach can be a powerful tool for searching for accreting binary systems in X-ray and optical catalogs.