Bulk motion measurements in clusters of galaxies with ATHENA-like
  missions
  The hierarchical formation of clusters of galaxies by accretion of material
releases gravitational energy which dissipates into the intracluster gas. The
process heats the material and generates gas turbulence and bulk motions and
thus kinetic pressure. Mapping the velocity fields of the moving subunits would
enable a new diagnostics tool for cluster formation studies and unbiased X-ray
mass estimates. The required spatially resolved high resolution spectroscopy is
not currently available. I demonstrate here the feasibility of detecting and
mapping the velocities of the bulk motions using the Doppler shift of the Fe
XXV K alpha line with the proposed ATHENA satellite.
