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

Abstract

On the basis of high-resolution two-dimensional hydrodynamic simulations, we show that the bulk gas motions in a cluster of galaxies, which are naturally expected during the process of the hierarchical structure formation of the universe, have a serious impact on the core. We found that the bulk gas motions represented by acoustic-gravity waves create local but strong turbulence, which reproduces the complicated X-ray structures recently observed in cluster cores. Moreover, if the wave amplitude is large enough, they can suppress the radiative cooling of the cores. Contrary to the previous studies, the heating is operated by the turbulence, not weak shocks. The turbulence could be detected in near-future space X-ray missions such as Astro-E2.