The Atacama Cosmology Telescope: stellar mass growth in massive galaxy clusters from DR5 over the past 7 billion years

We probe the stellar mass growth in a sample of 568 Sunyaev–Zel’dovich (SZ) selected galaxy clusters with masses greater than (Formula presented) and redshifts in the range (Formula presented), drawn from the fifth data release of the Atacama Cosmology Telescope (ACT DR5). By utilizing deep photometry from the tenth data release of the Dark Energy Camera Legacy Survey (DECaLS DR10), we construct redshift- and cluster mass-binned composite cluster stellar mass functions (SMFs), down to (Formula presented). This work presents the first analysis of the cluster SMF for this cluster sample at this epoch. We find that the characteristic stellar mass ((Formula presented) ) of the cluster SMF evolves marginally from (Formula presented), with most of the measurable growth occurring at (Formula presented). This suggests that most of the massive galaxy population in clusters ((Formula presented) ) is largely established by (Formula presented), with subsequent evolution driven by late-time assembly processes. The low-mass slope ((Formula presented) ) of the composite cluster SMF is flat at high-z ((Formula presented) ) but steepens at (Formula presented), suggesting an abundance of massive galaxies in high-z clusters compared to low-z clusters. We measure the evolution of cluster stellar mass fractions contained within galaxies with (Formula presented) between (Formula presented), and find evidence of significant growth, by a factor of 2.5, after accounting for the growth in cluster halo mass over this epoch.

Duke Scholars

Author Eve M Vavagiakis Physics