Orateur
Description
Cosmological constraints from galaxy clusters are currently limited by the precision of mass estimation. Non-thermal pressure support is suspected to be the primary culprit in biasing mass estimations from the intracluster medium (ICM). Moreover, (quasi-)turbulent gas motions are thought to be the dominant source of non-thermal pressure, in which case high resolution X-ray spectrographs on Hitomi and upcoming missions should greatly expand our knowledge. There is also an indirect approach which observes fluctuations in the surface brightness of clusters, accessed either in X-ray or Sunyaev-Zel’dovich (SZ) images. Exploring fluctuations in SZ images is relatively novel and should still be advantageous for probing turbulence in high-redshift clusters and cluster outskirts. I will present results of SZ (observed by SPT or MUSTANG-2) and X-ray (observations with XMM-Newton) fluctuations and the inferred pressure and density fluctuations.
