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

TL;DR

This study derives radial density profiles of dense cores in high-mass star-forming regions using 250 GHz continuum data, finding that the modified Bonnor-Ebert model best describes their structure and providing estimates of core properties.

Contribution

It demonstrates that the modified Bonnor-Ebert model effectively describes the density structure of dense cores in high-mass star-forming regions, with detailed analysis of core parameters.

Findings

Inner density profiles follow a power-law with index ~1.6

Modified Bonnor-Ebert model fits the data best in most cases

Non-thermal velocity dispersions are consistent with molecular line observations

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.