Galaxies and diffuse gas in protoclusters in cosmological hydrodynamical simulations

The study of protoclusters at cosmic noon is crucial for understanding how the environment and transformational processes, which peak in activity around this epoch, influence the evolution of cluster galaxies and the formation of the IntraCluster Medium (ICM). From an observational perspective, the combination of heterogeneous methods for searching for protoclusters in the high-z Universe and the limited statistics of current protocluster galaxy samples complicates our understanding of galaxy evolution in these extreme environments. In this context, theoretical models can significantly enhance our understanding of early cluster galaxy evolution. In particular, cosmological hydrodynamical simulations enable self-consistent modeling of gas dynamics and astrophysical processes within a cosmological framework.In this talk, I will present predictions from the latest version of the DIANOGA cosmological hydrodynamical simulations of galaxy clusters, focusing on the properties of galaxy populations at $z \sim 2$, across the transition from sparse protocluster structures to virialized clusters. I will explore how properties such as the star-forming main sequence, the galaxy stellar mass function, gas reservoirs, and the fraction of quenched galaxies depend on both local and global environments. To do this, I will also compare the DIANOGA protoclusters with the simulation of an average volume of the Universe, representative of the "field," which was simulated with the same galaxy formation model and resolution as the DIANOGA protoclusters. I will show how the overdense environment leaves a distinctive signature on the galaxy population in the extreme environments of cluster progenitors already at $z \sim 2$. Additionally, I will present the comparison of thermodynamic properties of the diffuse gas in massive halos with available observations at $z \sim 2$.