KMS of Xinjiang Astronomical Observatory, CAS
| Direct measurements of carbon and sulfur isotope ratios in the Milky Way | |
| Yan, Y. T.1; Henkel, C.1,2,3; Kobayashi, C.4; Menten, K. M.1; Gong, Y.1; Zhang, J. S.5; Yu, H. Z.5,6; Yang, K.7,8; Xie, J. J.9; Wang, Y. X.5 | |
| 2023-02-01 | |
| Source Publication | Astronomy & Astrophysics
 |
| ISSN | 0004-6361 |
| Volume | 670Pages:A98 |
| Contribution Rank | 3 |
| Abstract | Context. Isotope abundance ratios provide a powerful tool for tracing stellar nucleosynthesis, evaluating the composition of stellar ejecta, and constraining the chemical evolution of the Milky Way.Aims. We aim to measure the C-12/C-13, S-32/S-34, S-32/S-33, S-32/S-36, S-34/S-33, S-34/S-36, and S-33/S-36 isotope ratios across the Milky Way.Methods. With the IRAM 30 meter telescope, we performed observations of the J = 2-1 transitions of CS, (CS)-S-33, (CS)-S-34, (CS)-S-36, (CS)-C-13, (CS)-C-13-S-33, and (CS)-C-13-S-34 as well as the J = 3-2 transitions of (CS)-S-33, (CS)-S-34, (CS)-S-36, and (CS)-C-13 toward a large sample of 110 high-mass star-forming regions.Results. We measured the C-12/C-13, S-32/S-34, S-32/S-33, S-32/S-36, S-34/S-33, S-34/S-36, and S-33/S-36 abundance ratios with rare isotopologs of CS, thus avoiding significant saturation effects. With accurate distances obtained from parallax data, we confirm previously identified C-12/C-13 and S-32/S-34 gradients as a function of galactocentric distance. In the central molecular zone, C-12/C-13 ratios are higher than suggested by a linear fit to the disk values as a function of galactocentric radius. While S-32/S-34 ratios near the Galactic center and in the inner disk are similar, this is not the case for C-12/C-13, when comparing central values with those near galactocentric radii of 5 kpc. As was already known, there is no S-34/S-33 gradient but the average ratio of 4.35 +/- 0.44 derived from the J = 2-1 transition lines of (CS)-S-34 and (CS)-S-33 is well below previously reported values. A comparison between solar and local interstellar S-32/S-34 and S-34/S-33 ratios suggests that the Solar System may have been formed from gas with a particularly high S-34 abundance. For the first time, we report positive gradients of S-32/S-33, S-34/S-36, S-33/S-36, and S-32/S-36 in our Galaxy. The predicted C-12/C-13 ratios from the latest Galactic chemical-evolution models are in good agreement with our results. While S-32/S-34 and S-32/S-36 ratios show larger differences at larger galactocentric distances, S-32/S-33 ratios show an offset across the entire inner 12 kpc of the Milky Way. |
| Keyword | nuclear reactions nucleosynthesis abundances Galaxy evolution formation ISM HII regions molecules millimeter-wave observations galactic chemical evolution star-forming regions interstellar-medium molecular clouds trigonometric parallaxes c-12/c-13 ratios massive stars spiral arm fractionation Astronomy & Astrophysics |
| Subtype | Article |
| DOI | 10.1051/0004-6361/202244584 |
| Indexed By | SCI |
| Language | 英语 |
| WOS ID | WOS:000936621100010 |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.xao.ac.cn/handle/45760611-7/6656 |
| Collection | 中国科学院新疆天文台 |
| Corresponding Author | Yan, Y. T. |
| Affiliation | 1.Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany, e-mail: yyan@mpifr-bonn.mpg.de; astrotingyan@gmail.com; 2.Astronomy Department, Faculty of Science, King Abdulaziz University, PO Box 80203, Jeddah 21589, Saudi Arabia; 3.Xinjiang Astronomical Observatory, Chinese Academy of Sciences, 830011 Urumqi, PR China; 4.Centre for Astrophysics Research, Department of Physics, Astronomy and Mathematics, University of Hertfordshire,;(Hatfield AL10 9AB, UK; 5.Center for Astrophysics, Guangzhou University, 510006 Guangzhou, PR China; 6.Ural Federal University, 19 Mira Street, 620002 Ekaterinburg, Russia; 7.School of Astronomy and Space Science, Nanjing University, 163 Xianlin Avenue, Nanjing 210023, PR China; 8.Key Laboratory of Modern Astronomy and Astrophysics (Nanjing University), Ministry of Education, Nanjing 210023, PR China; 9.Shanghai Astronomical Observatory, Shanghai 200030, PR China |
| Recommended Citation GB/T 7714 | Yan, Y. T.,Henkel, C.,Kobayashi, C.,et al. Direct measurements of carbon and sulfur isotope ratios in the Milky Way[J]. Astronomy & Astrophysics,2023,670:A98. |
| APA | Yan, Y. T..,Henkel, C..,Kobayashi, C..,Menten, K. M..,Gong, Y..,...&Wang, Y. X..(2023).Direct measurements of carbon and sulfur isotope ratios in the Milky Way.Astronomy & Astrophysics,670,A98. |
| MLA | Yan, Y. T.,et al."Direct measurements of carbon and sulfur isotope ratios in the Milky Way".Astronomy & Astrophysics 670(2023):A98. |
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| Yan-2023-Direct meas（16545KB） | 期刊论文 | 出版稿 | 开放获取 | CC BY-NC-SA | View Application Full Text | |
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