Star-formation Properties of z ~ 1 Galaxy Clusters and Groups from Horizon Run 5

TL;DR

This study uses Horizon Run 5 simulations to analyze star formation in z ~ 0.87 galaxy clusters and groups, revealing that halo mass and environment influence the fraction of quiescent galaxies.

Contribution

It provides new insights into how halo mass and environmental factors affect star formation quenching in high-redshift galaxy clusters and groups.

Findings

Higher mass clusters have higher quiescent galaxy fractions.

Environmental properties mildly influence quiescent galaxy fractions.

Evolutionary history impacts star formation status of clusters.

Abstract

Quiescent galaxies are predominantly observed in local galaxy clusters. However, the fraction of quiescent galaxies in high-redshift clusters significantly varies among different clusters. In this study, we present the results of an analysis of the star formation (SF) properties of $z \sim 0.87$ clusters and groups from a cosmological hydrodynamical simulation Horizon Run 5. We investigate the correlation between the quiescent galaxy fraction (QF) of these model clusters/groups and their various internal or external properties. We find that halo mass is one of the most important characteristics as higher mass clusters and groups have higher QFs. We also find that other properties such as stellar-mass ratio and Friends-of-Friends fraction, which measures the proportion of the area around a cluster occupied by dense structures, may mildly affect the QFs of clusters and groups. This may indicate that the evolutionary history as well as the large-scale environment of clusters and groups also play a certain role in determining the SF status of high-redshift galaxy clusters and groups.