Hot Gas in the Local Group and Low-Redshift Intergalactic Medium

Abstract

There is increasing observational evidence that hot, highly ionized interstellar and intergalactic gas plays a significant role in the evolution of galaxies in the local universe. The primary spectral diagnostics of the warm-hot interstellar/intergalactic medium are ultraviolet and X-ray absorption lines of O VI and O VII. In this paper, I summarize some of the recent highlights of spectroscopic studies of hot gas in the Local Group and low-redshift universe. These highlights include investigations of the baryonic content of low-z O VI absorbers,evidence for a hot Galactic corona or Local Group medium, and the discovery of a highly ionized high velocity cloud system around the Milky Way.