My talk:
X-ray measurements of gas bulk motions in galaxy clusters
X-ray studies of velocity structures of the intracluster medium is one of the primary goals for future X-ray missions. High resolution spectroscopy will provide measurements of energy distributions not only in thermal but also in kinematic forms. These provide understanding of cluster formation and reductions of systematic uncertainties in cluster total masses for precise cosmology. Using Suzaku we have detected a motion of a sub component with a velocity of about 1500 km/s for the first time by X-ray of a X-ray bright merging cluster, Abell2256 (Tamura et al. 2011). We also detected a hint of bulk motion in the Perseus cluster core (Tamura et al. 2013). In addition we attempted to measure 'X-ray gas redshift' of clusters. We found that gas are moving in pair with galaxies at least in X-ray bright central regions. In addition to these new Suzaku results, future studies of gas bulk motion along with turbulent motions by X-ray micro calorimeter onboard ASTRO-H will be discussed.
