D. Field

Observations of vibrationally excited H2 in NGC2023 through high resolution imaging of the S(1) line emission at 2.121 μm

We have used the Canada‐France‐Hawaii Telescope to obtain an image of vibrationally excited H2 at 2.121 μm in NGC2023, at a spatial resolution of ∼1‘. The image has structures in the form of filaments of bright emission, showing clear spatial correlations and anti‐correlations with extended red emission (ERE). Our results have implications for the mechanism of the formation of ERE. Interpreting our observations in terms of the standard UV mechanism for the excitation of H2, we deduce that the surface of the emitting zone is characterized by undularions, whose morphology traces that of the emission.

OH Masers in Outflow Regions

We combine a sophisticated model of maser propagation with a simple model of an accelerating molecular outflow and show that the observation of different OH maser frequencies is consistent with emission from different parts of the outflow.