AN UNBIASED SURVEY FOR DENSE CORES IN THE LYNDS 1630 MOLECULAR CLOUD

We have completed an unbiased, systematic survey for dense cores within the L1630 (Orion B) molecular cloud. This survey provides the first complete census of dense (n > 10(4) cm-3) cores within a molecular cloud. To identify the dense gas, 3.6 square degrees of the L1630 cloud were surveyed in the J = 2 --> 1 transition of CS. CS emission was detected over 10% of the area surveyed, and this emission is not uniformly distributed throughout the cloud but is confined to 42 dense cores. The size, shape, velocity dispersion, and mass of these cores are examined. Comparison of the mass contained within dense cores with the total gas mass within the surveyed region, estimated from CO emission, reveals that the dense cores constitute only a small fraction (less-than-or-equal-to 19%) of the total cloud mass.