Ashby, MLNBergin, EAPlume, RCarpenter, JMNeufeld, DAChin, GErickson, NRGoldsmith, PFHarwit, MHowe, JEKleiner, SCKoch, DGPatten, BMSchieder, RSnell, Ronald L.Stauffer, JRTolls, VWang, ZWinnewisser, GZhang, YFMelnick, GJ2024-04-262024-04-262000-01-01https://doi.org/10.1086/312842https://hdl.handle.net/20.500.14394/3297<p>The published version is located at <a href="http://iopscience.iop.org/1538-4357/539/2/L115">http://iopscience.iop.org/1538-4357/539/2/L115</a></p>We present spectral line profiles for the 557 GHz 110 → 101 ground-state rotational transition of ortho-H216O for 18 Galactic star formation regions observed by the Submillimeter Wave Astronomy Satellite. Water is unambiguously detected in every source. The line profiles exhibit a wide variety 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 by variations in the relative strengths of the bulk flow and small-scale turbulent motions within the clouds. Bulk flow (infall, outflow) must be present in some cloud cores, and in certain cases this bulk flow dominates the turbulent motions.ISM : cloudsISM : moleculesradio lines : ISMstars : formationAstrophysics and Astronomyarticle