Star formation around the mid-infrared bubble CN 148
  We present a multi-wavelength study to analyse the star formation process
associated with the mid-infrared bubble CN 148 (H II region G10.3-0.1), which
harbors an O5V-O6V star. The arc-shaped distribution of molecular CO(2-1)
emission, the cold dust emission, and the polycyclic aromatic hydrocarbon
features trace a photodissociation region (PDR) around the H II region. We have
identified 371 young stellar objects (YSOs) in the selected region and,
interestingly, their spatial distribution correlates well with the PDR. 41% of
these YSOs are present in 13 clusters, each having visual extinction larger
than 16 mag. The clusters at the edges of the bubble (both northeast and
southwest) are found to be relatively younger than the clusters located further
away from the bubble. We also find that four 6.7 GHz methanol masers, two
Extended Green Objects, an ultra-compact H II region, and a massive protostar
candidate (as previously reported) are spatially positioned at the edges of the
bubble. The existence of an apparent age gradient in YSO clusters and different
early evolutionary stages of massive star formation around the bubble suggest
their origin to be influenced by an H II region expanding into the surrounding
interstellar medium. The data sets are suggestive of triggered star formation.
