Monday

The outskirts of galaxy clusters are dynamically active regions, where the infall of baryons and dark matter feeds the cluster and gives rise to complex hydrodynamic phenomena which will be potentially observed with forthcoming observational facilities in radio and X-ray bands. We have used Eulerian AMR cosmological simulations to quantify the mass growth of galaxy clusters, exploring the differences between dark matter and baryons, determining the mass assembly histories (MAHs) of each of the mass components and computing several proxies for the instantaneous mass accretion rate (MAR). The mass growth of both components is dominated by the contribution of major mergers, but high MARs can also occur during smooth accretion periods. We explored the correlations between MARs, merger events, and clusters' environments, finding the mean densities in 1 ≤ r/R200m ≤ 1.5 to correlate strongly with Γ200m in massive clusters that undergo major mergers through their MAH. Last, we present a novel approach to study the angularly resolved distribution of gas accretion flows in simulations, which allows us to extract and interpret the main contributions to the accretion picture and to assess systematic differences between the thermodynamical properties of each of these contributions using multipolar analysis. Amongst the most remarkable results, we find that the gas infalling through cosmic filaments has systematically lower entropy compared to the isotropic component, but we do not find a clear distinction in their temperature.