Intra-cluster Globular Clusters in a Simulated Galaxy Cluster

TL;DR

This study uses cosmological simulations to analyze the evolution and distribution of intra-cluster globular clusters, revealing a dominance of blue clusters and their extended spatial distribution, consistent with observations.

Contribution

It introduces a simulation-based method to track globular cluster populations and their intra-cluster component over cosmic time, highlighting the dominance of blue clusters in the intra-cluster space.

Findings

Approximately 60% of globular clusters are removed from their original halos by redshift 0.

Intra-cluster globular clusters are predominantly blue, increasing from 60% at redshift 0 to 83% at redshift 2.

Blue intra-cluster globular clusters are more spatially extended than red ones.

Abstract

Using a cosmological dark matter simulation of a galaxy-cluster halo, we follow the temporal evolution of its globular cluster population. To mimic the red and blue globular cluster populations, we select at high redshift $(z\sim 1)$ two sets of particles from individual galactic halos constrained by the fact that, at redshift $z=0$, they have density profiles similar to observed ones. At redshift $z=0$, approximately 60\% of our selected globular clusters were removed from their original halos building up the intra-cluster globular cluster population, while the remaining 40\% are still gravitationally bound to their original galactic halos. Since the blue population is more extended than the red one, the intra-cluster globular cluster population is dominated by blue globular clusters, with a relative fraction that grows from 60\% at redshift $z=0$ up to 83\% for redshift $z\sim 2$. In agreement with observational results for the Virgo galaxy cluster, the blue intra-cluster globular cluster population is more spatially extended than the red one, pointing to a tidally disrupted origin.