Evolution of interstellar molecular clouds: an integrated hydrodynamic study of a collapsing cloud

Theoretical models of interstellar clouds are ideally developed along the following lines. Starting from the basic physical processes, the equations of motion are formulated and solved - thereby yielding the internal structure of the cloud as a function of time, and the fluxes for the emitted radiations are calculated and compared with observations. The comparison is then used to test the model and to deduce information about current physical conditions and the cloud's past history. A report is presented on an integrated hydrodynamic model for interstellar clouds, by which is meant a model which treats all essential aspects of the physical structure in some detail. The essential components of an interstellar cloud model are: (1) dynamics; (2) energy transfer; (3) chemistry; and (4) radiation transfer. (author)