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

TL;DR

This paper reviews recent hydrodynamical simulation studies on turbulence generation in the cosmic large-scale structure, focusing on the roles of mergers and shocks in different gas phases.

Contribution

It introduces a subgrid scale model for unresolved turbulence and compares turbulence production in the WHIM and ICM phases.

Findings

Turbulence production varies significantly between WHIM and ICM.

Major and minor mergers, along with shocks, are key stirring mechanisms.

Simulations reveal different turbulence characteristics in distinct cosmic gas phases.

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.