Modeling the Outskirts of Galaxy Clusters with Cosmological Simulations
  We present cosmological simulations of galaxy clusters, with focus on the
cluster outskirts. We show that large-scale cosmic accretion and mergers
produce significant internal gas motions and inhomogeneous gas distribution
("clumpiness") in the intracluster medium (ICM) and introduce biases in
measurements of the ICM profiles and the cluster mass. We also show that
non-thermal pressure provided by the gas motions is one of the dominant sources
of theoretical uncertainties in cosmic microwave background secondary
anisotropies. We briefly discuss implications for cluster cosmology and future
prospects for understanding the physics of cluster outskirts using computer
simulations and multi-wavelength cluster surveys.
