Kauffmann, JensPillai, ThusharaShetty, RahulMyers, Philip C.Goodman, Alyssa2010-06-172010Kauffmann, Jens, Thushara Pillai, Rahul Shetty, Philip C. Myers, and Alyssa A. Goodman. 2010. The mass-size relation from clouds to cores. II. Solar neighborhood clouds. The Astrophysical Journal 716(1): 433-445.0004-637Xhttp://nrs.harvard.edu/urn-3:HUL.InstRepos:4258984We measure the mass and size of cloud fragments in several molecular clouds continuously over a wide range of spatial scales \((0.05 <\sim r/pc <\sim 3)\). Based on the recently developed "dendrogram-technique," this characterizes dense cores as well as the enveloping clouds. "Larson's Third Law" of constant column density, \(m(r) \alpha r^2\), is not well suited to describe the derived mass-size data. Solar neighborhood clouds not forming massive stars \((< \sim 10 M \odot\); Pipe Nebula, Taurus, Perseus, and Ophiuchus) obey \(m(r) \leq 870 M \odot (r/pc)^{1.33}\). In contrast to this, clouds forming massive stars (Orion A, G10.15 – 0.34, G11.11 – 0.12) do exceed the aforementioned relation. Thus, this limiting mass-size relation may approximate a threshold for the formation of massive stars. Across all clouds, cluster-forming cloud fragments are found to be—at given radius—more massive than fragments devoid of clusters. The cluster-bearing fragments are found to roughly obey a mass-size law \(m \ \alpha \ r^{1.27}\) (where the exponent is highly uncertain in any given cloud, but is certainly smaller than 1.5).en-USISM: cloudsmethods: data analysisstars: formationJournal Article2010-06-1710.1088/0004-637X/716/1/433