Characterization of the gas density fluctuations in the X-COP cluster sample

Clusters of galaxies accrete gas, galaxies, and substructures from their larger surroundings. This accretion process induces many shocks at all scales that heat the gas and generate perturbations, from which we expect the emergence of turbulent processes that will contribute to the thermalization of the whole intracluster medium (ICM). The characterization of these turbulent processes provides information on the history of the dynamic assembly of these massive halos. It can be done indirectly by studying the fluctuations of surface brightness at X-ray wavelengths. We have focused our work on a pilot sample of nearby clusters, the X-COP sample, to develop an analysis method that accounts for the stochastic nature of the process through the computation of a comprehensive error budget, under the assumption that density fluctuations originate from turbulent motions. We present the results of our analysis and the constraints we obtained for the parameters characterizing the turbulent cascade. We compare our results to other probes of the dynamical scales of galaxy clusters. Finally, we put the statistical analysis on the X-COP sample in perspective of larger and widely distributed samples such has CHEX-MATE.