Density Profiles in Molecular Cloud Cores Associated with High-Mass Star-Forming Regions

Abstract

Radial density profiles for the sample of dense cores associated with high-mass star-forming regions from southern hemisphere have been derived using the data of observations in continuum at 250 GHz. Radial density profiles for the inner regions of 16 cores (at distances $\la 0.2-0.8$ pc from the center) are close on average to the $\rho \propto r^{-\alpha }$ dependence, where $\alpha =1.6\pm 0.3$. In the outer regions density drops steeper. An analysis with various hydrostatic models showed that the modified Bonnor-Ebert model, which describes turbulent sphere confined by external pressure, is preferable compared with the logotrope and polytrope models practically in all cases. With a help of the Bonnor-Ebert model, estimates of central density in a core, non-thermal velocity dispersion and core size are obtained. The comparison of central densities with the densities derived earlier from the CS modeling reveals differences in several cases. The reasons of such differences are probably connected with the presence of density inhomogenities on the scales smaller than the telescope beam. In most cases non-thermal velocity dispersions are in agreement with the values obtained from molecular line observations.

12 pages, 3 figures, 4 tables

References in corpus (5)

• Theory of Star Formation
• Near Infrared Imaging Survey of Bok Globules: Density Structure
• Centrally Condensed Collapse of Starless Cores
• Chemical differentiation in regions of high-mass star formation I. CS, dust and N2H^+ in southern sources
• A Search for Small-Scale Clumpiness in Dense Cores of Molecular Clouds

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