Combining Semi-Analytic Models of Galaxy Formation with Simulations of Galaxy Clusters: the Need for AGN Heating

TL;DR

This paper combines semi-analytic galaxy formation models with hydrodynamical simulations of galaxy clusters to show that active galactic nuclei must significantly heat the intracluster medium to match observed entropy levels.

Contribution

It introduces a novel simulation approach integrating galaxy feedback from semi-analytic models with hydrodynamical cluster simulations, emphasizing the importance of AGN heating.

Findings

AGN inject large energy fractions into cluster media.

High entropy levels in clusters require sustained AGN feedback.

Simulation results support previous 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. (2008), who arrived at the same conclusion on the basis of purely semi-analytic reasoning.