Turbulent Flow and Stirring Mechanisms in the Cosmological Large-scale Structure

Abstract

Halo mergers and shock waves play a crucial role in the process of hierarchical clustering. Hydrodynamical simulations are the principal investigation tool in this field for theoreticians, and predict that a by-product of cluster formation and virialisation is the injection of turbulence in the cosmic flow. Here I will summarise results from a series of recent works focused on the main stirring mechanisms acting on baryons: minor and major cluster mergers, and curved shocks. Unresolved turbulence has been treated with the implementation of a subgrid scale model. Recent simulations show that the production of turbulence differs significantly for the warm-hot intergalactic medium (WHIM) and the intra-cluster medium (ICM), because of different stirring mechanisms acting in the two gas phases.