# X-ray Emissions from Accreting White Dwarfs: a Review

## TL;DR

This review summarizes current knowledge on X-ray emissions from accreting white dwarf binaries, covering observational techniques, types of emissions, and their contribution to galactic X-ray background, highlighting open questions and future directions.

## Contribution

It provides a comprehensive overview of X-ray emissions from various accreting white dwarf systems, integrating past and current observatories, data analysis methods, and discussing their galactic significance.

## Key findings

- X-ray emissions vary among different types of white dwarf binaries.
- Magnetic and non-magnetic CVs exhibit distinct X-ray characteristics.
- These binaries significantly contribute to the Galaxy's X-ray background.

## Abstract

Interacting binaries in which a white dwarf accretes material from a companion - cataclysmic variables (CVs) in which the mass donor is a Roche-lobe filling star on or near the main sequence, and symbiotic stars in which the mass donor is a late type giant - are relatively commonplace. They display a wide range of behaviors in the optical, X-rays, and other wavelengths, which still often baffle observers and theorists alike. Here I review the existing body of research on X-ray emissions from these objects for the benefits of both experts and newcomers to the field. I provide introductions to the past and current X-ray observatories, the types of known X-ray emissions from these objects, and the data analysis techniques relevant to this field. I then summarize of our knowledge regarding the X-ray emissions from magnetic CVs, non-magnetic CVs and symbiotic stars, and novae in eruption. I also discuss space density and the X-ray luminosity functions of these binaries and their contribution to the integrated X-ray emission from the Galaxy. I then discuss open questions and future prospects.