Strong Turbulence in the Cool Cores of Galaxy Clusters: Can Tsunamis Solve the Cooling Flow Problem?

Based on high-resolution two-dimensional hydrodynamic simulations, we showthat the bulk gas motions in a cluster of galaxies, which are naturallyexpected during the process of hierarchical structure formation of theuniverse, have a serous impact on the core. We found that the bulk gas motionsrepresented by acoustic-gravity waves create local but strong turbulence, whichreproduces the complicated X-ray structures recently observed in cluster cores.Moreover, if the wave amplitude is large enough, they can suppress theradiative cooling of the cores. Contrary to the previous studies, the heatingis operated by the turbulence, not weak shocks. The turbulence could bedetected in near-future space X-ray missions such as ASTRO-E2.