Molecular gas and triggered star formation surrounding Wolf-Rayet stars

TL;DR

This study investigates how Wolf-Rayet stars influence their surrounding molecular environment, revealing expanding shells, anti-correlations with stellar wind velocities, and evidence of triggered star formation in molecular shells.

Contribution

It provides new observational evidence linking Wolf-Rayet stellar winds to molecular shell expansion and triggered star formation, highlighting environmental impact.

Findings

Expanding molecular shells detected around Wolf-Rayet stars.

Molecular core properties anti-correlate with stellar wind velocities.

Enhanced young stellar object density in molecular shells indicating triggered star formation.

Abstract

The environments surrounding nine Wolf-Rayet stars were studied in molecular emission. Expanding shells were detected surrounding these WR stars (see left panels of Figure 1). The average masses and radii of the molecular cores surrounding these WR stars anti-correlate with the WR stellar wind velocities (middle panels of Figure 1), indicating the WR stars has great impact on their environments. The number density of Young Stellar Objects (YSOs) is enhanced in the molecular shells at $\sim$5 arcmin from the central WR star (lower-right panel of Figure 1). Through detailed studies of the molecular shells and YSOs, we find strong evidences of triggered star formation in the fragmented molecular shells (\cite[Liu et al. 2010]{liu_etal12}