NGC 7538 IRS1: Interaction of a polarized dust spiral and a molecular
  outflow
  We present dust polarization and CO molecular line images of NGC 7538 IRS1.
We combined data from the SMA, CARMA and JCMT telescopes to make images with
2.5 arcsec resolution at 230 and 345 GHz. The images show a remarkable spiral
pattern in both the dust polarization and molecular outflow. These data
dramatically illustrate the interplay between a high infall rate onto IRS1 and
a powerful outflow disrupting the dense, clumpy medium surrounding the star.
The images of the dust polarization and the CO outflow presented here provide
observational evidence for the exchange of energy and angular momentum between
the infall and the outflow. The spiral dust pattern, which rotates through over
180 degrees from IRS1, may be a clumpy filament wound up by conservation of
angular momentum in the infalling material. The redshifted CO emission ridge
traces the dust spiral closely through the MM dust cores, several of which may
contain protostars. We propose that the CO maps the boundary layer where the
outflow is ablating gas from the dense gas in the spiral.
