Investigation of Molecular Cloud Structure around Infrared Bubbles:
  CARMA Observations of N14, N22, and N74
  We present CARMA observations in 3.3 mm continuum and several molecular lines
of the surroundings of N14, N22, and N74, three infrared bubbles from the
GLIMPSE catalog. We have discovered 28 compact continuum sources and confirmed
their associations with the bubbles using velocity information from HCO+ and
HCN. We have also mapped small-scale structures of N2H+ emission in the
vicinity of the bubbles. By combining our data with survey data from GLIMPSE,
MIPSGAL, BGPS, and MAGPIS, we establish about half of our continuum sources as
star-forming cores. We also use survey data with the velocity information from
our molecular line observations to describe the morphology of the bubbles and
the nature of the fragmentation. We conclude from the properties of the
continuum sources that N74 likely is at the near kinematic distance, which was
previously unconfirmed. We also present tentative evidence of molecular clouds
being more fragmented on bubble rims compared to dark clouds, suggesting that
triggered star formation may occur, though our findings do not conform to a
classic collect-and-collapse model.
