On The Road To More Realistic Galaxy Cluster Simulations: The Effects of Radiative Cooling and Thermal Feedback Prescriptions on the Observational Properties of Simulated Galaxy Clusters

TL;DR

This paper explores how different radiative cooling and feedback models in galaxy cluster simulations affect observable properties, aiming to produce more realistic cluster populations and address discrepancies with actual observations.

Contribution

It introduces metallicity-dependent cooling and feedback adjustments in simulations, improving the realism of simulated galaxy cluster properties compared to previous models.

Findings

Metallicity-dependent cooling prevents early overcooling.

Adjusting feedback impacts X-ray observable properties.

Simulations still show discrepancies with real clusters.

Abstract

Flux limited X-ray surveys of galaxy clusters show that clusters come in two roughly equally proportioned varieties: "cool core" clusters (CCs) and non-"cool core" clusters (NCCs). In previous work, we have demonstrated using cosmological $N$-body + Eulerian hydrodynamic simulations that NCCs are often consistent with early major mergers events that destroy embryonic CCs. In this paper we extend those results and conduct a series of simulationsusing different methods of gas cooling, and of energy and metal feedback from supernovae, where we attempt to produce a population of clusters with realistic central cooling times, entropies, and temperatures. We find that the use of metallicity-dependent gas cooling is essential to prevent early overcooling,and that adjusting the amount of energy and metal feedback can have a significant impact on observable X-ray quantities of the gas. We are able to produce clusters with more realistic central observable quantities than have previously been attained. However, there are still significant discrepancies between the simulated clusters and observations, which indicates that a different approach to simulating galaxies in clusters is needed. We conclude by looking towards a promising subgrid method of modeling galaxy feedback in clusters which may help to ameliorate the discrepancies between simulations and observations.