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Title: SULFUR-BEARING MOLECULES IN MASSIVE STAR-FORMING REGIONS: OBSERVATIONS OF OCS, CS, H{sub 2}S, AND SO

Abstract

We studied the sulfur chemistry of massive star-forming regions through single-dish submillimeter spectroscopy. OCS, O{sup 13}CS, {sup 13}CS, H{sub 2}S, and SO transitions were observed toward a sample of massive star-forming regions with embedded UCH ii or CH ii regions. These sources could be divided into H ii-hot core and H ii-only sources based on their CH{sub 3}CN emission. Our results show that the OCS line of thirteen sources is optically thick, with optical depth ranging from 5 to 16. Column densities of these molecules were computed under LTE conditions. CS column densities were also derived using its optically thin isotopologue {sup 13}CS. H{sub 2}S is likely to be the most abundant gas-phase sulfuretted molecule in hot massive cores. Both the column density and abundance of sulfur-bearing molecules decrease significantly from H ii-hot core to H ii-only sources. Ages derived from hot core models appear to be consistent with star formation theories, suggesting that abundance ratios of [CS]/[SO], [SO]/[OCS], and [OCS]/[CS] could be used as chemical clocks in massive star-forming regions.

Authors:
;  [1];  [2];  [3];  [4]
  1. Shanghai Astronomical Observatory, 80 Nandan Road, Shanghai 20030 (China)
  2. Astronomy Department, University of Science and Technology, Chinese Academy of Sciences, Hefei 210008 (China)
  3. Center for Astrophysics, Guangzhou University, Guangzhou 510006 (China)
  4. National Astronomical Observatories, Chinese Academy of Sciences, A20 Datun Road, Chaoyang District, Beijing 100012 (China)
Publication Date:
OSTI Identifier:
22522034
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 802; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABSORPTION SPECTROSCOPY; ACETONITRILE; CARBON 13; CLOUDS; DENSITY; ELEMENT ABUNDANCE; EMISSION SPECTROSCOPY; HYDROGEN; HYDROGEN SULFIDES; LTE; MOLECULES; STAR EVOLUTION; STARS; SULFUR

Citation Formats

Li, Juan, Wang, Junzhi, Zhu, Qingfeng, Zhang, Jiangshui, and Li, Di, E-mail: lijuan@shao.ac.cn. SULFUR-BEARING MOLECULES IN MASSIVE STAR-FORMING REGIONS: OBSERVATIONS OF OCS, CS, H{sub 2}S, AND SO. United States: N. p., 2015. Web. doi:10.1088/0004-637X/802/1/40.
Li, Juan, Wang, Junzhi, Zhu, Qingfeng, Zhang, Jiangshui, & Li, Di, E-mail: lijuan@shao.ac.cn. SULFUR-BEARING MOLECULES IN MASSIVE STAR-FORMING REGIONS: OBSERVATIONS OF OCS, CS, H{sub 2}S, AND SO. United States. doi:10.1088/0004-637X/802/1/40.
Li, Juan, Wang, Junzhi, Zhu, Qingfeng, Zhang, Jiangshui, and Li, Di, E-mail: lijuan@shao.ac.cn. Fri . "SULFUR-BEARING MOLECULES IN MASSIVE STAR-FORMING REGIONS: OBSERVATIONS OF OCS, CS, H{sub 2}S, AND SO". United States. doi:10.1088/0004-637X/802/1/40.
@article{osti_22522034,
title = {SULFUR-BEARING MOLECULES IN MASSIVE STAR-FORMING REGIONS: OBSERVATIONS OF OCS, CS, H{sub 2}S, AND SO},
author = {Li, Juan and Wang, Junzhi and Zhu, Qingfeng and Zhang, Jiangshui and Li, Di, E-mail: lijuan@shao.ac.cn},
abstractNote = {We studied the sulfur chemistry of massive star-forming regions through single-dish submillimeter spectroscopy. OCS, O{sup 13}CS, {sup 13}CS, H{sub 2}S, and SO transitions were observed toward a sample of massive star-forming regions with embedded UCH ii or CH ii regions. These sources could be divided into H ii-hot core and H ii-only sources based on their CH{sub 3}CN emission. Our results show that the OCS line of thirteen sources is optically thick, with optical depth ranging from 5 to 16. Column densities of these molecules were computed under LTE conditions. CS column densities were also derived using its optically thin isotopologue {sup 13}CS. H{sub 2}S is likely to be the most abundant gas-phase sulfuretted molecule in hot massive cores. Both the column density and abundance of sulfur-bearing molecules decrease significantly from H ii-hot core to H ii-only sources. Ages derived from hot core models appear to be consistent with star formation theories, suggesting that abundance ratios of [CS]/[SO], [SO]/[OCS], and [OCS]/[CS] could be used as chemical clocks in massive star-forming regions.},
doi = {10.1088/0004-637X/802/1/40},
journal = {Astrophysical Journal},
number = 1,
volume = 802,
place = {United States},
year = {Fri Mar 20 00:00:00 EDT 2015},
month = {Fri Mar 20 00:00:00 EDT 2015}
}