Sulphur and carbon isotopes towards Galactic centre clouds

doi:10.1051/0004-6361/202038216

CORC > 新疆天文台 > 研究单元未命名 > 射电天文研究室 > 恒星形成与演化研究团组

	Sulphur and carbon isotopes towards Galactic centre clouds
	Humire, P. K.6; Thiel, V 6; Henkel, C.3,4,6; Belloche, A.6; Loison, J-C 2; Pillai, T.5,6; Riquelme, D.6; Wakelam, V 7; Langer, N.1,6; Hernandez-Gomez, A.6
刊名	ASTRONOMY & ASTROPHYSICS
	2020-10-23
卷号	642 页码:A222
关键词	Galaxy: centre submillimetre: ISM Galaxy: formation Galaxy: evolution stars: atmospheres submillimetre: general
ISSN号	0004-6361
DOI	10.1051/0004-6361/202038216
产权排序	3
英文摘要	Context. Measuring isotopic ratios is a sensitive technique used to obtain information on stellar nucleosynthesis and chemical evolution.Aims. We present measurements of the carbon and sulphur abundances in the interstellar medium of the central region of our Galaxy. The selected targets are the +50 km s(-1) Cloud and several line-of-sight clouds towards Sgr B2(N).Methods. Towards the +50 km s(-1) Cloud, we observed the J = 2-1 rotational transitions of (CS)-C-12-S-32, (CS)-C-12-S-34, (CS)-C-13-S-32, (CS)-C-12-S-33, and (CS)-C-13-S-34, and the J = 3-2 transitions of (CS)-C-12-S-32 and (CS)-C-12-S-34 with the IRAM-30 m telescope, as well as the J = 6-5 transitions of (CS)-C-12-S-34 and (CS)-C-13-S-32 with the APEX 12 m telescope, all in emission. The J = 2-1 rotational transitions of (CS)-C-12-S-32, (CS)-C-12-S-34, (CS)-C-13-S-32, and (CS)-C-13-S-34 were observed with ALMA in the envelope of Sgr B2(N), with those of (CS)-C-12-S-32 and (CS)-C-12-S-34 also observed in the line-of-sight clouds towards Sgr B2(N), all in absorption.Results. In the +50 km s(-1) Cloud we derive a C-12/C-13 isotopic ratio of 22.1 (+3.3)(-2.4) -2.4+3.3 , that leads, with the measured (CS)-C-13-S-32/(CS)-C-12-S-34 line intensity ratio, to a S-32/S-34 ratio of 16.3 (+3.0)(2.4) -2.4+3.0 . We also derive the S-32/S-34 isotopic ratio more directly from the two isotopologues (CS)-C-13-S-32 and (CS)-C-13-S-34, which leads to an independent S-32/S-34 estimation of 16.3 (+2.1)(-1.7) -1.7+2.1 and 17.9 5.0 for the +50 km s(-1) Cloud and Sgr B2(N), respectively. We also obtain a S-34/S-33 ratio of 4.3 +/- 0.2 in the +50 km s(-1) Cloud.Conclusions. Previous studies observed a decreasing trend in the S-32/S-34 isotopic ratios when approaching the Galactic centre. Our result indicates a termination of this tendency at least at a galactocentric distance of 130 (+60)(-30) -30+60 pc. This is at variance with findings based on C-12/C-13, N-14/N-15, and O-18/O-17 isotope ratios, where the above-mentioned trend is observed to continue right to the central molecular zone. This can indicate a drop in the production of massive stars at the Galactic centre, in the same line as recent metallicity gradient ([Fe/H]) studies, and opens the work towards a comparison with Galactic and stellar evolution models.
URL标识	查看原文
资助项目	International Max Planck Research School (IMPRS) for Astronomy and Astrophysics at the University of Bonn ; International Max Planck Research School (IMPRS) for Astronomy and Astrophysics at the University of Cologne ; INSU/CNRS (France) ; MPG (Germany) ; IGN (Spain)
WOS关键词	DENSE MOLECULAR CLOUDS ; INTERSTELLAR-MEDIUM ; CHEMICAL EVOLUTION ; MASSIVE STARS ; LINE SURVEY ; RATIOS ; ABUNDANCES ; MONOSULFIDE ; ABSORPTION ; CHEMISTRY
WOS研究方向	Astronomy & Astrophysics
语种	英语
出版者	EDP SCIENCES S A
WOS记录号	WOS:000586586300002
资助机构	International Max Planck Research School (IMPRS) for Astronomy and Astrophysics at the University of Bonn ; International Max Planck Research School (IMPRS) for Astronomy and Astrophysics at the University of Cologne ; INSU/CNRS (France) ; MPG (Germany) ; IGN (Spain)
内容类型	期刊论文
源URL	[http://ir.xao.ac.cn/handle/45760611-7/3716]
专题	恒星形成与演化研究团组
通讯作者	Humire, P. K.
作者单位	1.Univ Bonn, Argelander Inst Astron, Hugel 71, D-53121 Bonn, Germany 2.Univ Bordeaux, CNRS, Inst Sci Mol ISM, 351 Cours Liberat, F-33400 Talence, France 3.Chinese Acad Sci, Xinjiang Astron Observ, Urumqi 830011, Peoples R China 4.King Abdulaziz Univ, Dept Astron, POB 80203, Jeddah 21589, Saudi Arabia 5.Boston Univ, Inst Astrophys Res, 725 Commonwealth Ave, Boston, MA 02215 USA 6.Max Planck Inst Radioastron, Hugel 69, D-53121 Bonn, Germany 7.Univ Bordeaux, CNRS, Lab Astrophys Bordeaux, B18N,Allee Geoffroy St Hilaire, F-33615 Pessac, France
推荐引用方式 GB/T 7714	Humire, P. K.,Thiel, V,Henkel, C.,et al. Sulphur and carbon isotopes towards Galactic centre clouds[J]. ASTRONOMY & ASTROPHYSICS,2020,642:A222.
APA	Humire, P. K..,Thiel, V.,Henkel, C..,Belloche, A..,Loison, J-C.,...&Menten, K. M..(2020).Sulphur and carbon isotopes towards Galactic centre clouds.ASTRONOMY & ASTROPHYSICS,642,A222.
MLA	Humire, P. K.,et al."Sulphur and carbon isotopes towards Galactic centre clouds".ASTRONOMY & ASTROPHYSICS 642(2020):A222.