X-ray Halos around Massive Galaxies: Data and Theory

TL;DR

This paper reviews current observational and theoretical knowledge of hot X-ray halos around massive galaxies, highlighting their significance in galaxy evolution and future observational prospects.

Contribution

It provides a comprehensive overview of existing data and theories on X-ray halos and discusses future observational opportunities.

Findings

X-ray halos are key signatures of galaxy evolution.

Current models successfully explain many properties of X-ray halos.

Future instruments will enhance understanding of hot gaseous halos.

Abstract

The presence of gaseous X-ray halos around massive galaxies is a basic prediction of all past and modern structure formation simulations. The importance of these X-ray halos is further emphasized by the fact that they retain signatures of the physical processes that shape the evolution of galaxies from the highest redshift to the present day. In this review, we overview our current observational and theoretical understanding of hot gaseous X-ray halos around nearby massive galaxies and we also describe the prospects of observing X-ray halos with future instruments.