On the accretion history of galaxy clusters: temporal and spatial
  distribution
  We analyse the results of an Eulerian AMR cosmological simulation in order to
quantify the mass growth of galaxy clusters, exploring the differences between
dark matter and baryons. We have determined the mass assembly histories (MAHs)
of each of the mass components and computed several proxies for the
instantaneous mass accretion rate (MAR). The mass growth of both components is
clearly 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
$1 \leq r/R_{200m} \leq 1.5$ to correlate strongly with $\Gamma_{200m}$ in
massive clusters which undergo major mergers through their MAH. From the study
of the dark matter velocity profiles, we find a strong anticorrelation between
the MAR proxies $\Gamma_{200m}$ and $\alpha_{200m}$. Last, we present a novel
approach to study the angularly-resolved distribution of gas accretion flows in
simulations, which allows 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. We have preliminarily applied the method to the best
numerically-resolved cluster in our simulation. Amongst the most remarkable
results, we find that the gas infalling through the cosmic filaments has
systematically lower entropy compared to the isotropic component, but we do not
find a clear distinction in temperature.
