Molecular envelope around the HII region RCW 120
| Autor: | L. D. Anderson, Svetlana V. Salii, Sergei Kalenskii, D. S. Wiebe, Ya. N. Pavlyuchenkov, Paul A. Boley, A. M. Sobolev, Maria S. Kirsanova |
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| Rok vydání: | 2019 |
| Předmět: |
DYNAMICS
H II region H II REGIONS Infrared Extinction (astronomy) FOS: Physical sciences DUST Astrophysics 01 natural sciences KINEMATICS [ISM] FORMATION [STARS] 0103 physical sciences MASSIVE [STARS] 010303 astronomy & astrophysics Solar and Stellar Astrophysics (astro-ph.SR) Envelope (waves) Line (formation) Physics 010308 nuclear & particles physics Molecular cloud Condensation Astronomy and Astrophysics Astrophysics - Astrophysics of Galaxies Interstellar medium EXTINCTION Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science Astrophysics of Galaxies (astro-ph.GA) |
| Zdroj: | Mon. Not. R. Astron. Soc. Monthly Notices of the Royal Astronomical Society |
| DOI: | 10.48550/arxiv.1908.05394 |
| Popis: | The H II region RCW120 is a well-known object, which is often considered as a target to verify theoretical models of gas and dust dynamics in the interstellar medium. However, the exact geometry of RCW120 is still a matter of debate. In this work, we analyse observational data on molecular emission in RCW120 and show that 13CO(2-1) and C18O(2-1) lines are fitted by a 2D model representing a ring-like face-on structure. The changing of the C18O(3-2) line profile from double-peaked to single-peaked from the dense molecular Condensation 1 might be a signature of stalled expansion in this direction. In order to explain a self-absorption dip of the 13CO(2-1) and 13CO(3-2) lines, we suggest that RCW120 is surrounded by a diffuse molecular cloud, and find confirmation of this cloud on a map of interstellar extinction. Optically thick 13CO(2-1) emission and the infrared 8 um PAH band form a neutral envelope of the H II region resembling a ring, while the envelope breaks into separate clumps on images made with optically thin C18O(2-1) line and far-infrared dust emission. Comment: accepted to MNRAS |
| Databáze: | OpenAIRE |
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