The interaction of hydrodynamic shocks with self-gravitating clouds

TL;DR

This paper presents 3D simulations of how hydrodynamic shocks interact with self-gravitating clouds, revealing conditions that lead to gravitational collapse relevant to star formation regions.

Contribution

It provides new insights into the shock strength thresholds necessary to induce collapse in Bonnor-Ebert spheres using adaptive mesh refinement simulations.

Findings

Shock strength can trigger gravitational collapse in self-gravitating clouds.

Collapse depends on the shock's Mach number and cloud properties.

A simple estimate for critical shock strength is derived.

Abstract

We describe the results of 3D simulations of the interaction of hydrodynamic shocks with Bonnor-Ebert spheres performed with an Adaptive Mesh Refinement code. The calculations are isothermal and the clouds are embedded in a medium in which the sound speed is either four or ten times that in the cloud. The strengths of the shocks are such that they induce gravitational collapse in some cases and not in others and we derive a simple estimate for the shock strength required for this to occur. These results are relevant to dense cores and Bok globules in star forming regions subjected to shocks produced by stellar feedback.