doi.eso.org

• Mroczkowski, Tony [European Southern Observatory (ESO)]
• Stroe, Andra [Center for Astrophysics | Harvard & Smithsonian, Cambridge, Massachusetts, USA]
• Chasiotis-Klingner, Stella-Maria [European Southern Observatory (ESO)]

Galaxy clusters are both important cosmological probes and the large-scale environments influencing galaxy evolution. Processes such as ram pressure stripping, active galactic nucleus feedback and mergers, both on smaller galaxy-galaxy scales and larger cluster-cluster or cluster-subcluster scales play a major role in temporarily boosting and eventually throttling star formation in massive galaxies. The early assembly of galaxy clusters in particular remains a crucial phase for investigation. But it is a difficult one to probe, owing to their redshifts and the messy astrophysical processes involved in so-called “protoclusters”, defined as as-yet unvirialised massive assemblies of galaxies, gas, and large dark matter overdensities that will one day form into bona fide galaxy clusters. This second workshop in the Galaxy Cluster Formation series, GCF2021, followed many advances in the field of study covering merging clusters, high-z protoclusters, and cluster assembly since the first workshop, held in 2017, GCF2017.