Formation and Evolution of
Galaxy Clusters Across Cosmic Time

Brightest cluster galaxies (BCGs) are a peculiar family of objects: being the most luminous (and most massive) galaxies in the Universe, they are often located at the bottom of the gravitational potential of galaxy clusters. Because of their privileged position, their properties are severely influenced by, and in turn heavily affect, the extreme environmental conditions of galaxy cluster centers, making them attractive targets to benchmark models of galaxy formation. Using the DIANOGA hydrodynamical zoom-in cosmological simulation set of galaxy clusters, we analyze the dynamics traced by the stars belonging to the BCG and their surrounding diffuse component, forming the intracluster light (ICL), and compare them to the dynamics traced by dark matter and galaxies identified in the simulations. We compute scaling relations between velocity dispersion of the BCGs and clusters with the corresponding BCG stellar masses and total collapsed cluster mass, to find in general a good agreement with the most recent observational results. We find these relations to not significantly change up to redshift z=1, in line with a relatively slow accretion of the BCG stellar mass at late times. We weigh the impact on the observed velocity dispersion when dynamically excluding the ICL, with the use of machine learning techniques. We also examine the main features of the velocity dispersion profiles, as traced by stars, dark matter, and galaxies. Our results confirm that simulations can correctly describe the dynamics of BCGs and their surrounding stellar envelope, as determined by the past star-formation and assembly histories of the most massive galaxies of the Universe.