PROTOSTELLAR CANDIDATES IN A SAMPLE OF BRIGHT FAR-INFRARED IRAS SOURCES

We have observed CO and radio continuum emission in the direction of 39 bright 100-mu-m sources from the IRAS point source catalog, in an attempt to increase our understanding of the early stages of star formation. We found that all 39 sources are associated with molecular clouds. 12CO observations reveal generally high temperatures (half the objects have T(R)* = 15-40 K), and wide wings in the profiles (up to 34 km s-1). Twenty-six of the 39 molecular clouds have the wings on the central CO profile wide enough to suggest outflow activity. Six cm continuum observations give a range of results from no detectable continuum (< 300-mu-Jy) to well-developed H II regions (extended sources having flux densities of many hundreds of mJy). The radio and infrared luminosities for the sources are used to plot a log L-log T(eff) diagram from which we deduce that, of 24 sources for which we can assign distances and 6 cm flux densities, 11 are premain sequence objects. Four others are possibly in this category. The remainder cluster around the main sequence.