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C.C. Kaleida (The University of Georgia and The National Radio Astronomy Observatory), J.G. Mangum (The National Radio Astronomy Observatory)
The DR 21 (OH) region is an area of dense molecular gas, which appears to contain a cluster of newly forming stars. DR 21 (OH) lies approximately 2.6 pc to the north of the DR 21 HII region, the strongest and best studied 5 GHz source in the Cygnus X molecular cloud complex (Mangum, Wootten, & Mundy 1992; Downes & Rinehart 1966; Harris 1973). Measurements of the H2CO, CS, and CO emission toward the DR 21 (OH) molecular cloud were made by Mangum using the VLA, the OVRO Millimeter Array, and the Caltech Submillimeter Observatory. CS and H2CO molecular emission from this region was examined to determine kinetic temperature and spatial density structure, while CS and CO emission was utilized to probe the outflow properties of the young stellar objects. For the DR 21 (OH) main region a third line component has been discerned in addition to the two previously detected line components, dubbed MM1 and MM2 (Mangum, Wootten, & Mundy 1992). This third component constitutes a newly resolved broad wing component indicating an outflow. Careful inspection of the CO and CS emission reveals what appears to be a bipolar outflow that is most likely associated with the MM1 source. Calibrated values for the radiative temperature of each emission line were input into a Large Velocity Gradient (LVG) model, which models the source radiative transfer mechanisms to estimate spatial density, kinetic temperature, and molecular abundance. The densities determined from LVG modeling of the wing component were used along with spectral observations of its spatial extent to determine the flux density of the outflow. Information gained from the analysis of the kinetic temperature, spatial density, and outflow structure has been used to derive the history of the star formation process in this region.
Financial support provided by the NSF REU Program.
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Bulletin of the American Astronomical Society, 35#5
© 2003. The American Astronomical Soceity.