# Cosmic evolution of supermassive black holes: A view into the next two decades

## TL;DR

This paper reviews the progress in understanding supermassive black hole evolution over the past two decades and discusses future prospects with upcoming observatories to explore SMBH formation, growth, and their role in galaxy evolution.

## Contribution

It highlights the advancements made by X-ray surveys and outlines the key scientific questions and observational goals for the next two decades in SMBH research.

## Key findings

- Significant progress in SMBH and galaxy connection understanding.
- Future observatories will probe SMBH infancy at high redshifts.
- Anticipated insights into obscured and low-luminosity AGNs.

## Abstract

The discoveries made over the past 20 years by Chandra and XMM-Newton surveys in conjunction with multiwavelength imaging and spectroscopic data available in the same fields have significantly changed the view of the supermassive black hole (SMBH) and galaxy connection. These discoveries have opened up several exciting questions that are beyond the capabilities of current X-ray telescopes and will need to be addressed by observatories in the next two decades. As new observatories peer into the early Universe, we will begin to understand the physics and demographics of SMBH infancy (at $z>6$) and investigate the influence of their accretion on the formation of the first galaxies ($\S$ 2.1). We will also be able to understand the accretion and evolution over the cosmic history (at $z\sim$1-6) of the full population of black holes in galaxies, including low accretion rate, heavily obscured AGNs at luminosities beyond the reach of current X-ray surveys ($\S$2.2 and $\S$2.3), enabling us to resolve the connection between SMBH growth and their environment.