THE RELATIONSHIP OF DENSE GAS TO STAR-FORMATION IN THE MONOCEROS OB1 DARK CLOUD

We have conducted a CS survey of the 10 outflows and 30 IRAS sources i dentified by Margulis, Lada, & Snell (1988) and Margulis, Lada, and Yo ung (1989), in the Mon OB1 dark cloud to study the relationship betwee n outflows, young stellar objects, and dense cores in this cloud. We d etected the CS J = 2 --> 1 transition in the vicinity of 20 of the 30 IRAS sources, six of which are associated with the six most massive ou tflows in this cloud. We did not detect CS emission toward the four re maining outflows; three of these outflows are not associated with IRAS sources. The brightest CS J = 2 --> 1 emission is concentrated in two spatially extended regions encompassing five of the 10 outflows and e ight of the IRAS sources. Within the extended regions, CS line widths are similar to 30% broader near outflow lobes than on the line of sigh t toward IRAS sources. There is a strong correlation of CS antenna tem perature with IRAS source luminosity and a weaker correlation of CS li ne width with IRAS source luminosity for IRAS sources associated with outflows in Mon OB1. There is no apparent correlation of either CS ant enna temperature or line width with IRAS source luminosity for IRAS so urces not associated with outflows (quiescent sources). We have detect ed the CS J = 5 --> 4 transition in the vicinity of four outflow sourc es in this cloud and around none of the quiescent IRAS sources. The CS J = 5 --> 4 emission is extended around the two most massive outflows in the cloud and has been mapped in these regions. CS J = 7 --> 6 emi ssion has been detected and mapped about the brightest outflow source in this cloud (Alien's star; Alien 1972). The J = 7 --> 6 emission pea ks at the position of the IRAS source. The morphology of the J = 7 --> 6 emission differs from that of the J = 5 --> 4 emission.