The power of adaptive optics: A close look at a molecular cloud in NGC 2023

Observations of the reflection nebula NGC 2023, a region of recent star formation, have revealed small-scale structure in the associated molecular cloud, close to the exciting star, at a spatial resolution of 50 to 75 au. These results have been obtained using adaptive optics on the ESO 3.6-m telescope at La Silla, observing in the H-2 upsilon = 1-0 S(1) near-IR emission line at 2.121 mu m. Our observations are among the first to involve the use of adaptive optics combined with spectral line resolution. The observed fragment of molecular cloud, a remnant of the material from which the B-star in NGC 2023 formed, contains a number of features whose H-2 emission brightness contrast to the surrounding material is an order of magnitude. These structures are interpreted in terms of clumps of gas exhibiting a density contrast of at least an order of magnitude. We discuss the possibility that turbulence plays a role in the creation of the observed structures.