The origin of ICM enrichment in the outskirts of present-day galaxy clusters from cosmological hydrodynamical simulations

The uniformity of the intra-cluster medium (ICM) enrichment level in the outskirts of nearby galaxy clusters suggests that chemical elements were deposited and widely spread into the intergalactic medium before the cluster formation. This observational evidence is supported by numerical findings from cosmological hydrodynamical simulations, as presented in Biffi et al. (2017), including the effect of thermal feedback from active galactic nuclei. Here, we further investigate this picture, by tracing back in time the spatial origin and metallicity evolution of the gas residing at z=0 in the outskirts of simulated galaxy clusters. In these regions, we find a large distribution of iron abundanc…