STRUCTURE, CHEMISTRY, AND CLUMPING IN THE NGC-2071 (NORTH) MOLECULAR CLOUD

We have carried out a study of the NGC 2071 (North) molecular cloud in the 3 mm wavelength transitions of CO, (CO)-C-13, (CO)-O-18, CS, and HCO+ using the FCRAO 14 m telescope. We find that the distribution of CS and (CO)-O-18, two tracers that are widely used to trace dense gas in molecular clouds, are very different, and that they both differ appreciably from the previously published distribution of NH3. The (CO)-O-18, CS, and NH3 are all highly clumped; using the standard value for the fractional abundance of (CO)-O-18, we find that the four prominent clumps seen in this species are unbound. The explanation of the structure and chemical differentiation in this region may lie in the presence of an outflow which we find to be centered on the 26-40 L. source IRAS 05451 + 0037. The single significant peak of the CS emission coincides with the infrared source, one of the four ammonia peaks occurs there, while none of the other tracers has a significant maximum at this position. We suggest that the molecular abundances in this relatively large region have been significantly affected by the outflow and presence of the young stellar object. This effect, which may be relatively common, indicates that the apparent morphology of molecular clouds with recent star formation may be highly dependent on the molecular tracer used as a result of variations in the fractional abundances of different species.