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arXiv · 1605.01723

Stirred, not Clumped: Evolution of Temperature Profiles in the Outskirts of Galaxy Clusters

Camille Avestruz·Daisuke Nagai·Erwin T. Lau
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Abstract

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.

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Camille Avestruz, Daisuke Nagai, Erwin T. Lau. 2016-05-05. Stirred, not Clumped: Evolution of Temperature Profiles in the Outskirts of Galaxy Clusters. https://doi.org/10.3847/1538-4357%2F833%2F2%2F227

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