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Infall through the evolution of high-mass star-forming clumps

Wyrowski, F., Güsten, R., Menten, K.M., Wiesemeyer, H., Csengeri, T., Heyminck, S., Klein, B., König, C., Urquhart, J.S. (2016) Infall through the evolution of high-mass star-forming clumps. Astronomy and Astrophysics, 585 . ISSN 0004-6361. (doi:10.1051/0004-6361/201526361) (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided) (KAR id:55236)

The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided.
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With the GREAT receiver at the Stratospheric Observatory for Infrared Astronomy (SOFIA), nine massive molecular clumps have been observed in the ammonia 32+?22? line at 1.8 THz in a search for signatures of infall. The sources were selected from the ATLASGAL submillimeter dust continuum survey of our Galaxy. Clumps with high masses covering a range of evolutionary stages based on their infrared properties were chosen. The ammonia line was detected in all sources, leading to five new detections and one confirmation of a previous detection of redshifted absorption in front of their strong THz continuum as a probe of infall in the clumps. These detections include two clumps embedded in infrared dark clouds. The measured velocity shifts of the absorptions compared to optically thin C17O (3–2) emission are 0.3–2.8 km?s-1, corresponding to fractions of 3% to 30% of the free-fall velocities of the clumps. The ammonia infall signature is compared with complementary data of different transitions of HCN, HNC, CS, and HCO+, which are often used to probe infall because of their blue-skewed line profiles. The best agreement with the ammonia results is found for the HCO+ (4–3) transitions, but the latter is still strongly blended with emission from associated outflows. This outflow signature is far less prominent in the THz ammonia lines, which confirms it as a powerful probe of infall in molecular clumps. Infall rates in the range from 0.3 to 16 × 10-3 M?/yr were derived with a tentative correlation with the virial parameters of the clumps. The new observations show that infall on clump scales is ubiquitous through a wide range of evolutionary stages, from L/M covering about ten to several hundreds.

Item Type: Article
DOI/Identification number: 10.1051/0004-6361/201526361
Additional information: Unmapped bibliographic data: C7 - A149 [EPrints field already has value set] LA - English [Field not mapped to EPrints] J2 - Astron. Astrophys. [Field not mapped to EPrints] AD - Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, Bonn, Germany [Field not mapped to EPrints] AD - University of Applied Sciences Bonn-Rhein-Sieg, Grantham-Allee 20, Sankt Augustin, Germany [Field not mapped to EPrints] DB - Scopus [Field not mapped to EPrints] M3 - Article [Field not mapped to EPrints]
Uncontrolled keywords: ISM: kinematics and dynamics, ISM: molecules, stars: formation, Giant stars, Stars, Complementary data, Evolutionary stage, Infrared properties, ISM: Kinematics and dynamics, ISM: molecules, Redshifted absorption, Stars: formation, Stratospheric observatory for infrared astronomies, Ammonia
Subjects: Q Science > QB Astronomy > QB460 Astrophysics
Divisions: Divisions > Division of Natural Sciences > Physics and Astronomy
Depositing User: James Urquhart
Date Deposited: 04 May 2016 13:51 UTC
Last Modified: 17 Aug 2022 12:20 UTC
Resource URI: (The current URI for this page, for reference purposes)

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