Development of Turbulence in Post-shock Regions

TL;DR

This study uses high-resolution simulations to explore how shocks influence turbulence development in the interstellar medium, revealing energy amplification, anisotropy, and enhanced dissipation in post-shock regions.

Contribution

It provides new insights into turbulence evolution caused by shocks in supersonic, isothermal conditions, with detailed simulation results applicable to astrophysical environments.

Findings

Shocks amplify turbulent energy in post-shock regions.

Shocks induce anisotropic turbulence and vorticity orientation.

Turbulent energy and dissipation are heightened near shock fronts.

Abstract

Supersonic isothermal turbulence is ubiquitous in the interstellar medium. This work presents high-resolution AREPO hydrodynamical simulations of isolated shocks moving through supersonic turbulence to study the development and evolution of turbulence in the pre- and post-shock regions. We find that shocks can amplify turbulent energy in the post-shock region while inducing a preferential orientation for the vorticity. This results in the creation of anisotropic turbulence in the post-shock region. Turbulent energy and dissipation are also strongly enhanced near the shock front. By applying typical scalings from the cold neutral medium to simulations, we find that shocks moving into turbulence on the scale of superbubbles can generate compressive flows on the order of $10^{3} M_{\odot}$/Myr. Our results also show good agreement with related studies on turbulent fluctuations generated by shocks in pure fluid mechanics.