By Veronica Biffi

In this study, we investigate the possibility to reconstruct the velocity field of the intracluster medium in galaxy clusters undergoing major mergers. In these systems, large gas velocities are typically developed, which can be measured from the shift and broadening of heavy ion emission lines in X-ray spectra. To this scope, we employ hydrodynamical simulations of a major cluster-cluster merger and generate synthetic X-ray calorimeter observations with spectral resolution on the order of a few eV, like those achievable with Athena/X-IFU. We show how the high spectral resolution and a large collecting area of the Athena/X-IFU are crucial to successfully measure multiple ICM velocity components even in faint peripherical regions, that are consistent with the intrinsic simulation values.