Details

Autor(en) / Beteiligte

• Kirsanova, M S
• Pavlyuchenkov, Ya N
• Wiebe, D S
• Boley, P A
• Salii, S V
• Kalenskii, S V
• Sobolev, A M
• Anderson, L D

Titel

Molecular envelope around the HII region RCW 120

Ist Teil von

• Monthly notices of the Royal Astronomical Society, 2019-10, Vol.488 (4), p.5641-5650

Ort / Verlag

Oxford University Press

Erscheinungsjahr

2019

Link zum Volltext

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• ABSTRACT The H ii region RCW 120 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 RCW 120 is still a matter of debate. In this work, we analyse observational data on molecular emission in RCW 120 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 RCW 120 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 $\mu$m 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.