Galaxy groups and clusters are important systems for cosmology and galaxy evolution. The COSMOS survey has offered a unique data set to study the evolution of galaxy groups and clusters as well as their constituent galaxies.
In the latest contribution to this project, Dr. Gozaliasl and his collaborators provide a catalog of X-ray selected groups and clusters based on XMM and deep Chandra observations which offer an unprecedented spatial resolution in X-ray.
The brightest and most massive galaxies in the universe, the Brightest Cluster Galaxies (BCGs), tell a unique story of galaxy evolution. Today, BCGs are quiescent ellipticals hosted in relaxed galaxy clusters, with pasts fraught with mergers and high star formation rates (SFRs).
In a recent publication, Cooke et al. investigate how this active past may depend on local environment by estimating star formation in BCG progenitors in the COSMOS field out to a redshift of z ~ 3 (more than 11 billion years in the past).