BOK Globules and Small Molecular Clouds: Deep IRAS Photometry and 12CO Spectroscopy

The entire sample of small molecular clouds cataloged by Clemens and Barvainis (1988) has been probed using deep, coadded IRAS survey data analysis and (C-12)O spectroscopy. The far-IR colors are similar to those found for other amorphous Galactic constituents. The mean 12.25 micron color was 0.01, the mean 25/60 micron color was 0.68, and the mean 60/100 micron color was 0.70. The bulk of the dust mass was colder than 30 K. A very strong anticorrelation was found between dust optical depth and 60/100 micron color temperature. The mean far-IR luminosity of the sample is about 6.4 solar luminosities, the mean cloud mass is about 11 solar, the radius is around 0.35 pc, and the density is around 1000 H2/cu cm. Upper and lower limits for the number of these clouds in the Galaxy are 160,000 and 650,000. A total Galactic mass in Bok globules of about 3.5 million solar and a total luminosity of about two million solar is found.