Tracing the Quenching History in Galaxy Clusters in the EAGLE Simulation

One of the fundamental problems in modern astrophysics is the understanding of the role of environment in the evolution of galaxies. Many works, both theoretical and observational, have focused on these studies, suggesting possible solutions to interpret the data. Nevertheless, it is not yet clear what the main physical mechanisms that lead to the cessation of star formation, or quenching, in galaxies that reside in dense environments are. We have embarked in a new project aimed at using the state of the art EAGLE hydrodynamical simulation to trace the quenching history of galaxies in the 10 most massive clusters of this sample. In particular, our study is aimed at linking the quenching history of galaxies with the assembly history of the clusters, providing in this way a further test of the hierarchical paradigm of structure formation. By using both empirically- and theoretically- based definitions to separate star-forming and passive (quenched) galaxies, we separate our simulated sample into galaxies that were quenched in the clusters (in-situ quenched) and galaxies that were quenched before their host halo was accreted on to the clusters (pre-processed).