Dust Temperature Profiles in Dense Cores Associated With Massive Star-Forming Regions

Abstract

Using the APEX-12m telescope, continuum maps at 350~$\mu$m of eight gas-dust clouds from the southern hemisphere are obtained. Clouds are associated with the regions of massive star and star cluster formation and have dense cores. Core sizes estimated at the half maximum level are $\sim 0.1-0.2$~pc, core masses and mean gas densities lie in the ranges: $\sim 20-1000M_{\odot }$ and $\sim (0.3-7.3)\times 10^6$~cm${}^{-3}$, respectively. Comparison of the 350~$\mu$m data with the data of observations at 1.2~mm has been performed. From the ratios of intensities at two wavelengths convolved to the same angular resolution, spatial distributions of dust temperatures averaged over the line of sight are calculated. Dust temperature maps for most objects correlate with spatial distributions of intensities at 350~$\mu$m. A decrease in dust temperature with a distance from the center is detected in the cores. Dust temperature profiles in most cases are close to linear ones. Using a simple spherically-symmetric cloud model it is shown that temperature profiles similar to the observed ones can be obtained in a model with internal source by varying density profile parameters and setting $\beta$, a power-law index of the dust emissivity dependence on frequency, constant. It is shown that the dust temperatures estimates strongly depend on the accepted value of $\beta$. It is considered how possible variations of $\beta$ in a cloud can affect the results obtained.

27 pages, 4 figures

References in corpus (14)

• Multi-temperature mapping of dust structures throughout the Galactic Plane using the PPMAP tool with Herschel Hi-GAL data
• Shattering and coagulation of dust grains in interstellar turbulence
• Low dust emissivities and radial variations in the envelopes of Class 0 protostars: a signature of early grain growth?
• The almost ubiquitous association of 6.7 GHz methanol masers with dust
• Online Database of Class I Methanol Masers
• Chemical differentiation in regions of high-mass star formation I. CS, dust and N2H^+ in southern sources
• Dust opacity variations in the pre-stellar core L1544
• Physical Properties of the star-forming clusters in NGC 6334
• 84-GHz methanol masers, their relationship to 36-GHz methanol masers and their molecular environments
• Deep near-infrared adaptive optics observations of a young embedded cluster at the edge of the RCW 41 HII region
• Understanding the links among magnetic fields, filament, the bipolar bubble, and star formation in RCW57A using NIR polarimetry
• AzTEC Survey of the Central Molecular Zone: Increasing Spectral Index of Dust with Density
• Characterization of dense Planck clumps observed with Herschel and SCUBA-2
• IRAS 09002-4732: A Laboratory for the Formation of Rich Stellar Clusters

Cited by in corpus (1)

• Physical Properties and Kinematics of Dense Cores Associated with Regions of Massive Star Formation from the Southern Sky