Universität zu Köln

Xie, Jinjin, Fuller, Gary A., Li, Di ORCID: 0000-0003-3010-7661, Chen, Longfei, Ren, Zhiyuan, Wu, Jingwen, Duan, Yan, Wang, Junzhi, Li, Juan, Peretto, Nicolas, Liu, Tie and Shen, Zhiqiang (2021). The TMRT K band observations towards 26 infrared dark clouds: NH3, CCS, and HC3N. Sci. China-Phys. Mech. Astron., 64 (7). BEIJING: SCIENCE PRESS. ISSN 1869-1927

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Abstract

We present one of the first Shanghai Tian Ma Radio Telescope (TMRT) K Band observations towards a sample of 26 infrared dark clouds (IRDCs). We observed the (1,1), (2,2), (3,3), and (4,4) transitions of NH3 together with CCS (2(1)->1(0)) and HC3N J = 2-1, simultaneously. The survey dramatically increases the existing CCS-detected IRDC sample from 8 to 23, enabling a better statistical study of the ratios of carbon-chain molecules (CCM) to N-bearing molecules in IRDCs. With the newly developed hyperfine group ratio (HFGR) method of fitting NH3 inversion lines, we found the gas temperature to be between 10 and 18 K. The column density ratios of CCS to NH3 for most of the IRDCs are less than 10(-2), distinguishing IRDCs from low-mass star-forming regions. We carried out chemical evolution simulations based on a three-phase chemical model NAUTILUS. Our measurements of the column density ratios between CCM and NH3 are consistent with chemical evolutionary ages of less than or similar to 10(5) yr in the models. Comparisons of the data and chemical models suggest that CCS, HC3N, and NH3 are sensitive to the chemical evolutionary stages of the sources.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Xie, Jinjin UNSPECIFIED UNSPECIFIED UNSPECIFIED Fuller, Gary A. UNSPECIFIED UNSPECIFIED UNSPECIFIED Li, Di UNSPECIFIED orcid.org/0000-0003-3010-7661 UNSPECIFIED Chen, Longfei UNSPECIFIED UNSPECIFIED UNSPECIFIED Ren, Zhiyuan UNSPECIFIED UNSPECIFIED UNSPECIFIED Wu, Jingwen UNSPECIFIED UNSPECIFIED UNSPECIFIED Duan, Yan UNSPECIFIED UNSPECIFIED UNSPECIFIED Wang, Junzhi UNSPECIFIED UNSPECIFIED UNSPECIFIED Li, Juan UNSPECIFIED UNSPECIFIED UNSPECIFIED Peretto, Nicolas UNSPECIFIED UNSPECIFIED UNSPECIFIED Liu, Tie UNSPECIFIED UNSPECIFIED UNSPECIFIED Shen, Zhiqiang UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-597901
DOI:	10.1007/s11433-021-1695-0
Journal or Publication Title:	Sci. China-Phys. Mech. Astron.
Volume:	64
Number:	7
Date:	2021
Publisher:	SCIENCE PRESS
Place of Publication:	BEIJING
ISSN:	1869-1927
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language MASSIVE QUIESCENT CORES; GAS-GRAIN CHEMISTRY; CHEMICAL EVOLUTION; DENSE CORES; INITIAL CONDITIONS; STARLESS CORES; AMMONIA; SULFUR; ORION; SUBMILLIMETER Multiple languages Physics, Multidisciplinary Multiple languages
URI:	http://kups.ub.uni-koeln.de/id/eprint/59790