Star Formation Around Supergiant Shells in the LMC

TL;DR

This study investigates star formation around supergiant shells in the Large Magellanic Cloud, revealing that most current star formation occurs in unstable regions and is often triggered by shell expansion.

Contribution

It provides new evidence that triggered star formation is common around supergiant shells in the LMC, combining multi-wavelength data analysis.

Findings

Majority of current star formation occurs in gravitationally unstable regions.

Triggered star formation is prevalent at various scales.

Star formation correlates with shell expansion and gas distribution.

Abstract

We examine the recent star formation associated with four supergiant shells (SGSs) in the Large Magellanic Cloud (LMC): LMC 1, 4, 5, and 6, which have been shown to have simple expanding-shell structures. H II regions and OB associations are used to infer star formation in the last few Myr, while massive young stellar objects (YSOs) reveal the current ongoing star formation. Distributions of ionized, H I, and molecular components of the interstellar gas are compared with the sites of recent and current star formation to determine whether triggering has taken place. We find that a great majority of the current star formation has occurred in gravitationally unstable regions, and that evidence of triggered star formation is prevalent at both large and local scales.