Environmental dependence of X-ray and optical properties of galaxy clusters

TL;DR

This study investigates how the large-scale environment influences galaxy cluster properties, revealing that clusters in overdense regions tend to be richer, more massive, and exhibit higher X-ray luminosities and temperatures, affecting cosmological analyses.

Contribution

It introduces a comprehensive analysis of environmental effects on cluster properties using observational and simulation data, highlighting biases in cosmological parameter estimation.

Findings

Richer and more massive clusters are more common in overdense regions.

Clusters in overdense regions have higher X-ray luminosities and temperatures.

Environmental biases can impact cluster-based cosmological constraints.

Abstract

Galaxy clusters are widely used to constrain cosmological parameters through their properties, such as masses, luminosity and temperature distributions. One should take into account all kind of biases that could affect these analyses in order to obtain reliable constraints. In this work, we study the difference in the properties of clusters residing in different large scale environments, defined by their position within or outside of voids, and the density of their surrounding space. We use both observational and simulation cluster and void catalogues, i.e. XCS and redMaPPer clusters, BOSS voids, and Magneticum simulations. We devise two different environmental proxies for the clusters and study their redshift, richness, mass, X-ray luminosity and temperature distributions as well as some properties of their galaxy populations. We use the Kolmogorov-Smirnov two-sample test to discover that richer and more massive clusters are more prevalent in overdense regions and outside of voids. We also find that clusters of matched richness and mass in overdense regions and outside voids tend to have higher X-ray luminosities and temperatures. These differences could have important implications for precision cosmology with clusters of galaxies, since cluster mass calibrations can vary with environment.