An analysis of water line profiles in star formation regions observed by the Submillimeter Wave Astronomy Satellite

We present spectral line profiles for the 557 GHz 1(10)-->1(01) ground-stat e rotational transition of ortho-(H2O)-O-16 for 18 Galactic star formation regions observed by the Submillimeter Wave Astronomy Satellite. Water is un ambiguously detected in every source. The line profiles exhibit a wide vari ety of shapes, including single-peaked spectra and self-reversed profiles. We interpret these profiles using a Monte Carlo code to model the radiative transport. The observed variations in the line profiles can be explained b y variations in the relative strengths of the bulk flow and small-scale tur bulent motions within the clouds. Bulk flow (infall, outflow) must be prese nt in some cloud cores, and in certain cases this bulk flow dominates the t urbulent motions.