Studies of star formation in isolated small dark clouds – I. A catalogue of southern Bok globules: optical and IRAS properties

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Abstract
A comprehensive list of small southern molecular clouds (globules) has been established from the survey of southern dark clouds of Hartley et al. Only the most opaque globules, and those with diameters less than 10 arcmin, were included in the list. These are found to form an entirely complementary sample to that of Clemens & Barvainis in the northern sky. In this and the following paper, a detailed study of the clouds is undertaken through an examination of their optical and IRAS properties, and radio observations of ammonia. The aim of the study is to determine their physical characteristics, their role in the formation of low-mass stars, and the physical mechanism that either triggers the star formation process or stabilizes the globules against collapse. The globules are predominantly elliptical. There is some evidence that the apparent galactic latitude distribution of our globules (as well as that of the Clemens & Barvainis sample) is more highly concentrated towards the galactic plane than that of the large molecular cloud complexes identified through CO surveys. This suggests that there are very few high-latitude globules, or that selection effects play a major role in defining the apparent distribution. Of the 169 globules studied, 76 are found to have IRAS sources lying towards them (totalling 83 sources). The IRAS sample is dominated by cooler sources than is the sample found to be associated with molecular cloud cores by Beichman et al., and predominantly exhibits the colours of embedded sources.

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