Multifrequency Studies of Massive Cores with Complex Spatial and Kinematic Structures
Journal article, 2016

Five regions of massive-star formation have been observed in various molecular lines in the frequency range similar to 85-89 GHz. The studied regions comprise dense cores, which host young stellar objects. The physical parameters of the cores are estimated, including the kinetic temperatures (similar to 20-40 K), the sizes of the emitting regions (similar to 0.1-0.6 pc), and the virial masses (similar to 40-500 M-circle dot). The column densities and abundances of various molecules are calculated assuming Local Thermodynamical Equilibrium(LTE). The core in 99.982+4.17, which is associated with the weakest IRAS source, is characterized by reduced molecular abundances. The molecular line widths decrease with increasing distance from the core centers (b). For b greater than or similar to 0.1 pc, the dependences Delta V (b) are close to power laws (alpha b(-p)), where p varies from similar to 0.2 to similar to 0.5, depending on the object. In four cores, the asymmetries of the optically thick HCN(1-0) and HCO+(1-0) lines indicates systematic motions along the line of sight: collapse in two cores and expansion in two others. Approximate estimates of the accretion rates in the collapsing cores indicate that the forming stars have masses exceeding the solar mass.

fu-orionis stars

extended green objects

astronomical journal



star-forming regions


cutcheon wh

llanen md

bright-rimmed clouds



young stellar population

molecular cloud cores

publications of the astronomical society of the pacific


infrared dark clouds



ghz methanol masers


Astronomy & Astrophysics


L. E. Pirogov

Russian Academy of Sciences

Valery Shulga

Institute of Radio Astronomy National Academy of Sciences of Ukraine

I Zinchenko

Russian Academy of Sciences

Peter Zemlyanukha

Russian Academy of Sciences

Lobachevsky University

Oleksii Patoka

Institute of Radio Astronomy National Academy of Sciences of Ukraine

Magnus Thomasson

Chalmers, Earth and Space Sciences, Onsala Space Observatory

Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics

Astronomy Reports

1063-7729 (ISSN) 1562-6881 (eISSN)

Vol. 60 10 904-923

Subject Categories

Astronomy, Astrophysics and Cosmology



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