Star Formation in Disk Galaxies. III. Does stellar feedback result in cloud death?

TL;DR

This study investigates how stellar feedback influences the lifecycle of giant molecular clouds in disk galaxies, finding that thermal feedback suppresses star formation but does not lead to cloud destruction, highlighting the dominance of gravitational effects.

Contribution

It provides a comparative analysis of GMC evolution under different feedback mechanisms, emphasizing the limited role of thermal feedback in cloud destruction.

Findings

Thermal feedback suppresses star formation without destroying GMCs.

Clouds survive stellar feedback, maintaining properties similar to no-feedback scenarios.

Gravitational interactions and disk shear are more influential than thermal feedback in GMC evolution.

Abstract

Stellar feedback, star formation and gravitational interactions are major controlling forces in the evolution of Giant Molecular Clouds (GMCs). To explore their relative roles, we examine the properties and evolution of GMCs forming in an isolated galactic disk simulation that includes both localised thermal feedback and photoelectric heating. The results are compared with the three previous simulations in this series which consists of a model with no star formation, star formation but no form of feedback and star formation with photoelectric heating in a set with steadily increasing physical effects. We find that the addition of localised thermal feedback greatly suppresses star formation but does not destroy the surrounding GMC, giving cloud properties closely resembling the run in which no stellar physics is included. The outflows from the feedback reduce the mass of the cloud but do not destroy it, allowing the cloud to survive its stellar children. This suggests that weak thermal feedback such as the lower bound expected for supernova may play a relatively minor role in the galactic structure of quiescent Milky Way-type galaxies, compared to gravitational interactions and disk shear.