Combining Semi-analytic Models with Simulations of Galaxy Clusters: the Need for Heating from Active Galactic Nuclei

TL;DR

This paper combines semi-analytic galaxy formation models with hydrodynamical simulations of galaxy clusters to show that active galactic nuclei must provide significant heating to explain observed high entropy levels.

Contribution

It introduces a novel simulation approach integrating realistic galaxy feedback sources, demonstrating the necessity of AGN heating in cluster evolution.

Findings

AGN inject large energy fractions into intracluster media

High entropy levels in clusters require sustained AGN activity

Simulation results support semi-analytic conclusions

Abstract

We present hydrodynamical N-body simulations of clusters of galaxies with feedback taken from semi-analytic models of galaxy formation. The advantage of this technique is that the source of feedback in our simulations is a population of galaxies that closely resembles that found in the real universe. We demonstrate that, to achieve the high entropy levels found in clusters, active galactic nuclei must inject a large fraction of their energy into the intergalactic/intracluster media throughout the growth period of the central black hole. These simulations reinforce the argument of Bower et al., who arrived at the same conclusion on the basis of purely semi-analytic reasoning.