Ionization front-driven turbulence in the clumpy interstellar medium

TL;DR

This study uses 3D simulations to show how ionization fronts from massive stars induce turbulence and dissolve dense interstellar clumps, highlighting a rapid turbulence generation mechanism near such stars.

Contribution

It introduces a detailed simulation of ionization front interactions with dense clumps, revealing a new mechanism for turbulence generation in the interstellar medium.

Findings

Ionization fronts create turbulence in dense clumps.

Clumps are fully dissolved by the process.

Mechanism is efficient near massive stars.

Abstract

We present 3D radiation-gasdynamical simulations of an ionization front running into a dense clump. In our setup, a B0 star irradiates an overdensity which is at a distance of 10 pc and modelled as a supercritical 100 M_sol Bonnor-Ebert sphere. The radiation from the star heats up the gas and creates a shock front that expands into the interstellar medium. The shock compresses the clump material while the ionizing radiation heats it up. The outcome of this "cloud-crushing" process is a fully turbulent gas in the wake of the clump. In the end, the clump entirely dissolves. We propose that this mechanism is very efficient in creating short-living supersonic turbulence in the vicinity of massive stars.