Preview

PDF (Published version) 149021 - Redshi...pdf | Download (1MB) | Preview

Abstract

Context: Gravitational collapse is one of the most important processes in high-mass star formation. Compared with the classic blue-skewed profiles, redshifted absorption against continuum emission is a more reliable method to detect inward motions within high-mass star formation regions.Aims: We aim to test if methanol transitions can be used to trace infall motions within high-mass star formation regions.Methods: Using the Effelsberg-100 m, IRAM-30 m, and APEX-12 m telescopes, we carried out observations of 37 and 16 methanol transitions towards two well-known collapsing dense clumps, W31C (G10.6−0.4) and W3(OH), to search for redshifted absorption features or inverse P-Cygni profiles.Results: Redshifted absorption is observed in 14 and 11 methanol transitions towards W31C and W3(OH), respectively. The infall velocities fitted from a simple two-layer model agree with previously reported values derived from other tracers, suggesting that redshifted methanol absorption is a reliable tracer of infall motions within high-mass star formation regions. Our observations indicate the presence of large-scale inward motions, and the mass infall rates are roughly estimated to be ≳10-3 M⊙ yr-1, which supports the global hierarchical collapse and clump-fed scenario.Conclusions: With the aid of bright continuum sources and the overcooling of methanol transitions leading to enhanced absorption, redshifted methanol absorption can trace infall motions within high-mass star formation regions hosting bright H II regions.

Item Type:	Article
Authors/Creators:	Yang, WJ and Menten, KM and Yang, AY and Wyrowski, F and Gong, Y and Ellingsen, SP and Henkel, C and Chen, X and Xu, Y
Keywords:	stars: formation - ISM: kinematics and dynamics - ISM: individual objects: W3(OH) - ISM: individual objects: W31C(G10.6-0.4) - ISM: molecules - radio lines: ISM
Journal or Publication Title:	Astronomy & Astrophysics
Publisher:	E D P Sciences
ISSN:	0004-6361
DOI / ID Number:	https://doi.org/10.1051/0004-6361/202142811
Copyright Information:	© W. J. Yang et al. 2022 Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution 4.0 International (CC BY 4.0) License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Related URLs:	Google Scholar: Ellingsen, SP UTAS Profile: Ellingsen, SP
Item Statistics:	View statistics for this item

Actions (login required)

Item Control Page