Microphysics of ICM from X-ray images: effective equation of state, turbulence, heating

The only Hitomi direct velocity measurement in the core of the Perseus cluster showed a surprising consistency with the indirect velocity measurements from the analysis of gas fluctuations imprinted in the high-resolution X-ray images provided by Chandra. This result motivates to extend the analysis of fluctuations on a sample of galaxy clusters, which I will present during the meeting. In particular, I will discuss the effective equation of state of ICM fluctuations, velocity measurements on a range of spatial scales, down to small, microphysical scales, and will address the role of gas motions in the ICM heating. I will emphasize the main assumptions of the analysis, which should be studied numerically in future