AMMONIA AND (CO)-O-18 IN GLOBULES

A complete and unbiased survey of 237 dust glob, ules from the catalog of Clemens & Barvainis (1988) has been made in the (1,1) and (2,2) in version lines of ammonia. Whereas NH3(1,1) emission is found in 74 sou rces, the NH3(2,2) line is detected only in 17 sources. Complete ammon ia maps of 15 globules show angular sizes of between 45 '' and 85 ''. The FWHP angular sizes of these clouds based on the (CO)-O-18(1-0) emi ssion are between 2 and 9 arcminutes. Accurate determinations of the k inetic temperatures show that the temperatures of all the globules in the study are between 8.5 and 11.5 K. From NH3 excitation temperatures of between 4.5 to 8 K we determine H-2 densities with typical values around (2-4). 10(4) cm(-3). Presumably, the more extended (CO)-O-18 em ission arises from lower density gas. The masses of the mapped globule s range up to 100 solar masses with typical values between 2 and 45 so lar masses. Considerations of stability from a comparison of turbulent , thermal and gravitational energies show that all the globules are cl ose to equilibrium.