Seeking for the leading actor on the cosmic stage: Galaxies versus supermassive black holes

Abstract

A major development in extragalactic astrophysics in recent years has been the realization that active galactic nuclei (AGN), which signpost accretion events onto supermassive black holes (SMBHs) [1, 2], may play a fundamental role in the formation and evolution of galaxies. Understanding the physics that drive the growth of SMBH across cosmic time is therefore important for having a complete picture of galaxy formation. The two processes of galaxy and BH evolution can no longer be regarded as separate, as was the case until about 10 years ago, but need to be studied in conjunction.