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| Galactic Interstellar Sulfur Isotopes: A Radial(32)S/S-34 Gradient? | |
Yu, H. Z.1; Zhang, J. S.1; Henkel, C.2,3; Yan, Y. T.1,2; Liu, W.1; Tang, X. D.4,5 ; Langer, N.2,6; Luan, T. C.1; Chen, J. L.1; Wang, Y. X.1; Deng, G. G.1; Zou, Y. P.1
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| 2020-08-01 | |
| Source Publication | ASTROPHYSICAL JOURNAL
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| ISSN | 0004-637X |
| Volume | 899Issue:2Pages:145 |
| Contribution Rank | 4 |
| Abstract | We present observations of(12)C(32)S,(CS)-C-12-S-34,(CS)-C-13-S-32, and(12)C(33)SJ = 2-1 lines toward a large sample of massive star-forming regions by using the Arizona Radio Observatory 12 m telescope and the IRAM 30 m. Taking new measurements of the carbon(12)C/C-13 ratio, the(32)S/S-34 isotope ratio was determined from the integrated(13)C(32)S/(CS)-C-12-S-34 line intensity ratios for our sample. Our analysis shows a(32)S/S-34 gradient from the inner Galaxy out to a galactocentric distance of 12 kpc. An unweighted least-squares fit to our data yields(32)S/S-34 = (1.56 0.17)D-GC + (6.75 1.22) with a correlation coefficient of 0.77. Errors represent 1 sigma standard deviations. Testing this result by (a) excluding the Galactic center region, (b) excluding all sources with (CS)-S-34 opacities >0.25, (c) combining our data and old data from previous study, and (d) using different sets of carbon isotope ratios leads to the conclusion that the observed(32)S/S-34 gradient is not an artifact but persists irrespective of the choice of sample and carbon isotope data. A gradient with rising(32)S/S-34 values as a function of galactocentric radius implies that the solar system ratio should be larger than that of the local interstellar medium. With the new carbon isotope ratios, we indeed obtain a local(32)S/S-34 isotope ratio about 10% below the solar system one, as expected in the case of decreasing(32)S/S-34 ratios with time and increased amounts of stellar processing. However, taking older carbon isotope ratios based on a lesser amount of data, such a decrease is not seen. No systematic variation of(34)S/S-33 ratios along galactocentric distance was found. The average value is 5.9 1.5, the error denoting the standard deviation of an individual measurement. |
| Keyword | Interstellar medium Stellar nucleosynthesis Abundance ratios Radio astronomy Stellar abundances Galaxy chemical evolution Interstellar molecules Milky Way Galaxy |
| DOI | 10.3847/1538-4357/aba8f1 |
| URL | 查看原文 |
| Indexed By | SCI |
| Language | 英语 |
| WOS Keyword | STAR-FORMING REGIONS ; CARBON MONOSULFIDE ; ABUNDANCES ; AMMONIA ; EVOLUTION ; REDSHIFT ; CORES ; S-36 ; NH3 |
| Funding Project | Natural Science Foundation of China[11590782] ; China Scholarship Council (CSC) |
| WOS Research Area | Astronomy & Astrophysics |
| WOS Subject | Astronomy & Astrophysics |
| WOS ID | WOS:000565732700001 |
| Publisher | IOP PUBLISHING LTD |
| Funding Organization | Natural Science Foundation of China ; China Scholarship Council (CSC) |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.xao.ac.cn/handle/45760611-7/3643 |
| Collection | 射电天文研究室_恒星形成与演化研究团组 |
| Corresponding Author | Zhang, J. S. |
| Affiliation | 1.Guangzhou Univ, Ctr Astrophys, Guangzhou 510006, Peoples R China 2.Max Planck Inst Radioastron, Hugel 69, D-53121 Bonn, Germany 3.King Abdulaziz Univ, Astron Dept, POB 80203, Jeddah 21589, Saudi Arabia 4.Chinese Acad Sci, Xinjiang Astron Observ, Urumqi 830011, Peoples R China 5.Chinese Acad Sci, Key Lab Radio Astron, Urumqi, Peoples R China 6.Univ Bonn, Argelander Inst Astron, Hugel 71, D-53121 Bonn, Germany |
| Recommended Citation GB/T 7714 | Yu, H. Z.,Zhang, J. S.,Henkel, C.,et al. Galactic Interstellar Sulfur Isotopes: A Radial(32)S/S-34 Gradient?[J]. ASTROPHYSICAL JOURNAL,2020,899(2):145. |
| APA | Yu, H. Z..,Zhang, J. S..,Henkel, C..,Yan, Y. T..,Liu, W..,...&Zou, Y. P..(2020).Galactic Interstellar Sulfur Isotopes: A Radial(32)S/S-34 Gradient?.ASTROPHYSICAL JOURNAL,899(2),145. |
| MLA | Yu, H. Z.,et al."Galactic Interstellar Sulfur Isotopes: A Radial(32)S/S-34 Gradient?".ASTROPHYSICAL JOURNAL 899.2(2020):145. |
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| Yu-2020-Galactic Int（5401KB） | 期刊论文 | 出版稿 | 开放获取 | CC BY-NC-SA | View Application Full Text | |
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