Studying the emergence of the red sequence through galaxy clustering: host halo masses at z > 2

TL;DR

This study investigates galaxy clustering at high redshift using deep infrared data, revealing that passive galaxies are strongly clustered in massive halos, supporting models where halo mass influences galaxy quenching.

Contribution

First measurement of clustering for passive galaxies at z > 2, demonstrating the link between halo mass and galaxy quenching at early cosmic times.

Findings

Passive galaxies are hosted by halos > 5 x 10^12 M_sun.

Passive galaxies are more strongly clustered than star-forming ones.

Low-mass passive galaxies tend to reside in the most massive halos.

Abstract

We use the UKIDSS Ultra-Deep Survey, the deepest degree-scale near-infrared survey to date, to investigate the clustering of star-forming and passive galaxies to z ~ 3.5. Our new measurements include the first determination of the clustering for passive galaxies at z > 2, which we achieve using a cross-correlation technique. We find that passive galaxies are the most strongly clustered, typically hosted by massive dark matter halos with M_halo > 5 x 10^12 M_sun irrespective of redshift or stellar mass. Our findings are consistent with models in which a critical halo mass determines the transition from star-forming to passive galaxies. Star-forming galaxies show no strong correlation between stellar mass and halo mass, but passive galaxies show evidence for an anti-correlation; low-mass passive galaxies appear, on average, to be located in the most massive halos. These results can be understood if the termination of star formation is most efficient for galaxies of low stellar mass in very dense environments.