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The Hitomi X-ray satellite has provided the first direct measurements of theplasma velocity dispersion in a galaxy cluster. It finds a relatively"quiescent" gas with a line-of-sight velocity dispersion ~ 160 km/s, at 30 kpcto 60 kpc from the cluster center. This is surprising given the presence ofjets and X-ray cavities that indicates on-going activity and feedback from theactive galactic nucleus (AGN) at the cluster center. Using a set of mock Hitomiobservations generated from a suite of state-of-the-art cosmological clustersimulations, and an isolated but higher resolution simulation of gas physics inthe cluster core, including the effects of cooling and AGN feedback, we examinethe likelihood of Hitomi detecting a cluster with the observed velocities. Aslong as the Perseus has not experienced a major merger in the last fewgigayears, and AGN feedback is operating in a "gentle" mode, we reproduce thelevel of gas motions observed by Hitomi. The frequent mechanical AGN feedbackgenerates net line-of-sight velocity dispersions ~100-200 km/s, bracketing thevalues measured in the Perseus core. The large-scale velocity shear observedacross the core, on the other hand, is generated mainly by cosmic accretionsuch as mergers. We discuss the implications of these results for AGN feedbackphysics and cluster cosmology and progress that needs to be made in bothsimulations and observations, including a Hitomi re-flight andcalorimeter-based instruments with higher spatial resolution.

Physical Origins of Gas Motions in Galaxy Cluster Cores: Interpreting Hitomi Observations of the Perseus Cluster