Supernova Feedback in Molecular Clouds: Global Evolution and Dynamics

TL;DR

This study uses magnetohydrodynamical simulations to explore how supernova feedback influences the evolution, dynamics, and star formation within molecular clouds, revealing limited cloud disruption but significant effects on star formation rates.

Contribution

It demonstrates that supernova feedback alone cannot fully disrupt molecular clouds but significantly impacts star formation efficiency and rate, especially with clustered supernovae.

Findings

Supernova feedback disperses small (~10 pc) regions within 1 Myr.

Clustered supernovae create large hot bubbles dispersing bigger cloud areas.

Star formation efficiency is reduced by a factor of 2 due to supernova feedback.

Abstract

We use magnetohydrodynamical simulations of converging warm neutral medium flows to analyse the formation and global evolution of magnetised and turbulent molecular clouds subject to supernova feedback from massive stars. We show that supernova feedback alone fails to disrupt entire, gravitationally bound, molecular clouds, but is able to disperse small--sized (~10 pc) regions on timescales of less than 1 Myr. Efficient radiative cooling of the supernova remnant as well as strong compression of the surrounding gas result in non-persistent energy and momentum input from the supernovae. However, if the time between subsequent supernovae is short and they are clustered, large hot bubbles form that disperse larger regions of the parental cloud. On longer timescales, supernova feedback increases the amount of gas with moderate temperatures (T~300-3000 K). Despite its inability to disrupt molecular clouds, supernova feedback leaves a strong imprint on the star formation process. We find an overall reduction of the star formation efficiency by a factor of 2 and of the star formation rate by roughly factors of 2-4.