The Mass-Size Relation from Clouds to Cores. II. Solar Neighborhood Clouds
Abstract
We measure the mass and size of cloud fragments in several molecular clouds continuously over a wide range of spatial scales (0.05 < r / pc < 3). Based on the recently developed "dendrogram-technique", this characterizes dense cores as well as the enveloping clouds. "Larson's 3rd Law" of constant column density, m(r) = C*r^2, is not well suited to describe the derived mass-size data. Solar neighborhood clouds not forming massive stars (< 10 M_sun; Pipe Nebula, Taurus, Perseus, and Ophiuchus) obey m(r) < 870 M_sun (r / pc)^1.33 . In contrast to this, clouds forming massive stars (Orion A, G10.150.34, G11.110.12) 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 = C*r^1.27 (where the exponent is highly uncertain in any given cloud, but is certainly smaller than 1.5).
Keywords
Cite
@article{arxiv.1004.1170,
title = {The Mass-Size Relation from Clouds to Cores. II. Solar Neighborhood Clouds},
author = {Jens Kauffmann and Thushara Pillai and Rahul Shetty and Philip C. Myers and Alyssa A. Goodman},
journal= {arXiv preprint arXiv:1004.1170},
year = {2015}
}
Comments
accepted to the Astrophysical Journal