| The circumgalactic medium (CGM) plays a pivotal role in the formation and evolution of galaxies from the highest redshifts to the present epoch. The CGM serves as a reservoir of gas fueling star formation, is located at the intersection of cosmic inflows and outflows, and mediates the dynamical processes responsible for the growth of galaxies. While UV observations have made significant progress in exploring the warm phases of the CGM, for galaxies of Milky Way mass and greater, the bulk of baryons reside in the CGM as diffuse, hot, X-ray-emitting gas, detectable via X-ray observatories. Therefore, to draw a complete picture of the CGM, and hence the physical processes involved in the evolution of galaxies, it is key to probe the hot, X-ray-emitting gas. The X-ray phases not only harbor a substantial fraction of baryons but also retain the imprint of physical processes such as energetic feedback from supernovae and supermassive black holes. In this presentation, I will discuss our current understanding of the hot X-ray-emitting CGM and will briefly present future prospects. |
