Abstract:
We investigate the in
fl
uence of Wolf
–
Rayet
(
W-R
)
stars on their surrounding star-forming molecular clouds. We
study
fi
ve regions containing W-R stars in the inner Galactic plane
(
l
∼
[
14
°
–
52
°
]
)
, using multiwavelength data
from near-infrared to radio wavelengths. Analysis of
13
CO line data reveals that these W-R stars have developed
gas-de
fi
cient cavities in addition to molecular shells with expansion velocities of a few kilometers per second. The
pressure owing to stellar winds primarily drives these expanding shells and sweeps up the surrounding matter to
distances of a few parsecs. The column densities of shells are enhanced by a minimum of 14% for one region to a
maximum of 88% for another region with respect to the column densities within their central cavities. No active
star formation
—
including molecular condensations, protostars, or ionized gas
—
is found inside the cavities,
whereas such features are observed around the molecular shells. Although the expansion of ionized gas is
considered an effective mechanism to trigger star formation, the dynamical ages of the H
II
regions in our sample
are generally not suf
fi
ciently long to do so ef
fi
ciently. Overall, our results hint at the possible importance of
negative W-R wind-driven feedback on the gas-de
fi
cient cavities, where star formation is quenched as a
consequence. In addition, the presence of active star formation around the molecular shells indicates that W-R stars
may also assist in accumulating molecular gas, and that they could initiate star formation around those shells
