Hot Gas in Clusters, Groups and Galaxies: From SMBH Outbursts to Cosmology

Abstract

This review focuses on recent results related to the energy feedback from the central SMBH into the surrounding cool gas and on the constraints that X‐ray observations of clusters place on cosmological parameters. X‐ray observations show that outbursts from SMBHs are common, even at the present epoch. Measurements of the cavities and shocks produced by these outbursts in the hot gas in clusters, groups and galaxies determine the outburst energy, age, duration and recurrence frequency. The energy from outbursts can balance that lost through radiative cooling and can reduce star formation and galaxy growth. On a global scale, cluster studies provide complementary constraints on cosmological parameters, and currently constrain the Dark Energy equation of state to the same or better levels as other methods.