Ricerc@Sapienza

The hot intra-cluster medium (ICM hereafter) in clusters of galaxies is primarily supported by thermal pressure.
Nevertheless, hydrodynamical simulations have shown that a non-negligible contribution to the total pressure may come from non-thermal ordered motions, e.g. radial infall or coherent rotation and streams. Therefore, a correct evaluation of the ICM pressure is fundamental to obtain accurate estimates of cluster masses,
which are in turn very important for the constraining of cosmological parameters. The aim of this project is to continue the investigation of the detectability of rotational motions of the ICM through observational probes at different wavelengths, namely in the microwave region through the kinetic Sunyaev--Zel'dovich (kSZ) effect, and in the X-ray and optical bands through spectroscopic measurements from the gas and the galaxy members, respectively. In a recent work, we produced maps of the temperature distortion produced by the kSZ for the six most relaxed object in a sample of massive clusters from MUSIC simulations (Sembolini et al., 2013) that also show peculiar rotational properties, and we recovered the rotational properties within two standard deviations at most, from the fit to a suitable theoretical model. We treated both a simplified case -- accounting only for rotation -- and a complete one characterized by the adding of the cluster bulk motion. Motivated by these promising results, we are currently working on a refinement of this analysis, by properly accounting for observational effects affecting measurements on real clusters, and through complementary observational approaches towards the same synthetic data set.