Finding proto-clusters to trace galaxy evolution: I. The finder and its performance

TL;DR

This paper introduces a new method for identifying proto-clusters in high-redshift galaxy surveys, demonstrating high accuracy and purity in simulations, and linking galaxy evolution from early to present-day clusters.

Contribution

The paper presents a novel proto-cluster finder based on galaxy groups, with performance validated on simulations, enabling studies of galaxy and cluster evolution.

Findings

Correctly identifies over 85% of true proto-clusters.

Achieves more than 95% purity in proto-cluster detection.

Mass estimates are within 0.25 dex of true values.

Abstract

We develop a method to identify proto-clusters based on dark matter halos represented by galaxy groups selected from surveys of galaxies at high redshift. We test the performance of this method on halos in N-body simulations, and find it can correctly identify more than 85% of the true proto-clusters with $\gtrsim$ 95% purity and with mass estimates typical within 0.25 dex from their true values. We show how the information provided by the proto-clusters can be used to link galaxies in present-day clusters of galaxies with their high redshift progenitors. Our tests show that the proto-clusters identified by our method can recover reliably the progenitor stellar mass distribution of galaxies, thereby providing an avenue to investigate the formation and evolution of present-day galaxy clusters and their member galaxies.