Millimetre spectral line mapping observations towards four massive star-forming H ii regions
Author
Li, ShanghuoWang, Junzhi
Zhang, Zhi-Yu

Fang, Min

Li, Juan
Zhang, Jiangshui
Fan, Junhui
Zhu, Qingfeng
Li, Fei
Affiliation
Univ Arizona, Dept AstronIssue Date
2017-01-05Keywords
stars: formationstars: massive
stars: winds, outflows
ISM: clouds
radio lines: stars
submillimetre: stars
Metadata
Show full item recordPublisher
OXFORD UNIV PRESSCitation
Millimetre spectral line mapping observations towards four massive star-forming H ii regions 2017, 466 (1):248 Monthly Notices of the Royal Astronomical SocietyRights
© 2016 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society.Collection Information
This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.Abstract
We present spectral line mapping observations towards four massive star-forming regions Cepheus A, DR21S, S76E and G34.26+0.15 - with the IRAM 30-m telescope at the 2 and 3 mm bands. In total, 396 spectral lines from 51 molecules, one helium recombination line, 10 hydrogen recombination lines and 16 unidentified lines were detected in these four sources. An emission line of nitrosyl cyanide (ONCN, 14(0), 14-13(0), (13)) was detected in G34.26+0.15, as the first detection in massive star-forming regions. We found that c-C3H2 and NH2D show enhancement in shocked regions, as suggested by the evidence of SiO and/or SO emission. The column density and rotational temperature of CH3CN were estimated with the rotational diagram method for all four sources. Isotope abundance ratios of C-12/C-13 were derived using HC3N and its C-13 isotopologue, which were around 40 in all four massive star-forming regions and slightly lower than the local interstellar value (similar to 65). The N-14/N-15 and O-16/O-18 abundance ratios in these sources were also derived using the double isotopic method, which were slightly lower than in the local interstellar medium. Except for Cep A, the S-33/S-34 ratios in the other three targets were derived, which were similar to that in the local interstellar medium. The column density ratios of N(DCN)/N(HCN) and N( DCO+)/N(HCO+) in these sources were more than two orders of magnitude higher than the elemental [D]/[H] ratio, which is 1.5 x 10(-5). Our results show that the later stage sources, G34.26+0.15 in particular, present more molecular species than earlier stage sources. Evidence of shock activity is seen in all stages studied.ISSN
0035-87111365-2966
Version
Final published versionSponsors
China Ministry of Science and Technology under the State Key Development Programme for Basic Research [2012CB821800]; Natural Science Foundation of China [11173013]; European Research Council [321302]; Natural Science Foundation of Anhui Province of China [1408085MA13]ae974a485f413a2113503eed53cd6c53
10.1093/mnras/stw3076