The Dynamics of Dense Cores in the Perseus Molecular Cloud II: the Relationship between Dense Cores and the Cloud

Abstract

We utilize the extensive datasets available for the Perseus molecular cloud to analyze the relationship between the kinematics of small-scale dense cores and the larger structures in which they are embedded. The kinematic measures presented here can be used in conjunction with those discussed in our previous work as strong observational constraints that numerical simulations (or analytic models) of star formation should match. We find that dense cores have small motions with respect to the (^{13}CO) gas, about one third of the (^{13}CO) velocity dispersion along the same line of sight. Within each extinction region, the core- to-core velocity dispersion is about half of the total ((^{13}CO)) velocity dispersion seen in the region. Large-scale velocity gradients account for roughly half of the total velocity dispersion in each region, similar to what is predicted from large-scale turbulent modes following a power spectrum of (P(k) \alpha \ k^{−4}).