The physical structure of the dark cloud B5.

A consistent physical of the dark cloud B5 was derived, on the basis of recent line observations of the 1-0 and 2-1 lines of CO-12, CO-13, and C-18(0). In constructing the model, half of each observational scan was scaled against the mean radius of the cloud. Fits to mean data were derived on the basis of regression analysis. It is found that the simulated cloud appeared to maintain a hydrostatic equilibrium, due to cosmic ray heating. In the region near the edge of the cloud, temperature was found to increase strongly, and the chemical abundances decreased by nearly three orders of magnitude. The implied field strength of the simulated cloud was consistent with the observational data. The disadvantages of velocity gradient models for detailed dark cloud analysis are discussed, in comparison with the present modelling technique. The numerical results are given in a series of tables.