Stirred, not Clumped: Evolution of Temperature Profiles in the Outskirts
  of Galaxy Clusters
  Recent statistical X-ray measurements of the intracluster medium (ICM)
indicate that gas temperature profiles in the outskirts of galaxy clusters
deviate from self-similar evolution. Using a mass-limited sample of galaxy
clusters from cosmological hydrodynamical simulations, we show that the
departure from self-similarity can be explained by non-thermal gas motions
driven by mergers and accretion. Contrary to previous claims, gaseous
substructures only play a minor role in the temperature evolution in cluster
outskirts. A careful choice of halo overdensity definition in self-similar
scaling mitigates these departures. Our work highlights the importance of
non-thermal gas motions in ICM evolution and the use of galaxy clusters as
cosmological probes.
