Massive black holes and their galaxies

TL;DR

This chapter reviews the detection, properties, and coevolution of supermassive black holes and their host galaxies across cosmic history, integrating observations and simulations.

Contribution

It synthesizes current knowledge on black hole detection, population, and coevolution, highlighting recent observational and simulation-based insights.

Findings

Black holes are present in nearly all local galaxies.

Black hole properties correlate tightly with host galaxy features.

Evidence suggests coevolution from early cosmic times to the present.

Abstract

Almost every galaxy in the local Universe is observed to have a massive black hole in the centre. The properties of these black holes are observed to tightly correlate with those of their host galaxy which has been interpreted as coevolution regulated by black hole feedback. This coevolution spans most of cosmic history, as the first active black holes, so-called active galactic nuclei, are already observed as early as $z\sim10$. In this chapter, we lay out how we can find supermassive black holes, review what we know about the population of black holes and their host galaxies from observations, and summarise what we have learned about their coevolution across cosmic time from both observations and simulations.