Dense cores in dark clouds. II - NH3 observations and star formation

All strong, 'dense core' sources and (2, 2)-line observations are mapped in the present results of a survey of about 100 visually opaque regions in nearby dark clouds in the 1.3-cm (J, K) = (1, 1) line of NH3. Line shapes are compared with cloud motion models, and source density, size, and temperature are compared with equilibrium and stability requirements. These are found to indicate that most dense cores are in the early stages of collapse, or in near-critical equilibrium. If the latter possibility is the case, support is probably furnished by a combination of thermal and subsonic turbulent motions. Positions of the 10 known dense cores in Taurus-Auriga are correlated with emission-line star group positions. The results obtained cumulatively suggest that most of the dense cores described will form low mass stars in the next one million years.