The effect of photoionising feedback on star formation in isolated and colliding clouds

TL;DR

This study examines how cloud collisions and photoionising feedback influence star formation, revealing that collisions significantly boost star formation efficiency and feedback effects vary depending on collision dynamics.

Contribution

It provides new insights into the combined effects of cloud collisions and photoionising feedback on star formation efficiency and stellar mass distribution.

Findings

Cloud collisions increase star formation efficiency by a factor of 10.

Feedback can both promote and hinder star formation depending on the environment.

Collisions steepen the stellar mass function's high-mass end.

Abstract

We investigate star formation occurring in idealised giant molecular clouds, comparing structures that evolve in isolation versus those undergoing a collision. Two different collision speeds are investigated and the impact of photoionising radiation from the stars is determined. We find that a colliding system leads to more massive star formation both with and without the addition of feedback, raising overall star formation efficiencies (SFE) by a factor of 10 and steepening the high-mass end of the stellar mass function. This rise in SFE is due to increased turbulent compression during the cloud collision. While feedback can both promote and hinder star formation in the isolated system, it increases the SFE by approximately 1.5 times in the colliding case when the thermal speed of the resulting HII regions matches the shock propagation speed in the collision.