Evolution of Supermassive Black Holes from Cosmological Simulations

TL;DR

This paper uses cosmological simulations to study the growth and evolution of supermassive black holes, successfully reproducing many observed properties but failing to produce the most massive black holes at high redshift.

Contribution

It presents a detailed simulation model of black hole growth from seeds, matching several observed correlations and evolution patterns, with insights into their formation history.

Findings

Simulations reproduce the black hole mass function at z=0.

Black hole growth mainly via accretion and mergers.

Fail to produce black holes above 10^9 solar masses at z~6.

Abstract

The correlations between the mass of supermassive black holes and properties of their host galaxies are investigated through cosmological simulations. Black holes grow from seeds of 100 solar masses inserted into density peaks present in the redshift range 12-15. Seeds grow essentially by accreting matter from a nuclear disk and also by coalescences resulting from merger episodes. At z=0, our simulations reproduce the black hole mass function and the correlations of the black hole mass both with stellar velocity dispersion and host dark halo mass. Moreover, the evolution of the black hole mass density derived from the present simulations agrees with that derived from the bolometric luminosity function of quasars, indicating that the average accretion history of seeds is adequately reproduced . However, our simulations are unable to form black holes with masses above $10^9 M_{\odot}$ at $z\sim 6$, whose existence is inferred from the bright quasars detected by the Sloan survey in this redshift range.