{"title":"银河系中心人马座B2扩展包层的硫同位素","authors":"Qingxu Li, Juan Li, Siqi Zheng, Junzhi Wang, Feng Gao, Yajun Wu","doi":"10.1093/pasj/psad078","DOIUrl":null,"url":null,"abstract":"Isotopic ratios are good tools for probing stellar nucleosynthesis and chemical evolution. We perform high-sensitivity mapping observations of the J = 7–6 rotational transitions of OCS, OC34S, O13CS, and OC33S toward the Galactic Center giant molecular cloud Sagittarius B2 with the IRAM 30 m telescope. Positions with optically thin and uncontaminated lines are chosen to determine the sulfur isotope ratios. A 32S/34S ratio of 17.1 ± 0.9 was derived with OCS and OC34S lines, while a 34S/33S ratio of 6.8 ± 1.9 was derived directly from the integrated intensity ratio of OC34S and OC33S. With independent and accurate measurements of the 32S/34S ratio, our results confirm the termination of the decreasing trend of 32S/34S ratios toward the Galactic Center, suggesting a drop in the production of massive stars at the Galactic Center.","PeriodicalId":20733,"journal":{"name":"Publications of the Astronomical Society of Japan","volume":"12 5","pages":""},"PeriodicalIF":2.2000,"publicationDate":"2023-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Sulfur isotopes toward the extended envelope of Sagittarius B2 in the Galactic Center\",\"authors\":\"Qingxu Li, Juan Li, Siqi Zheng, Junzhi Wang, Feng Gao, Yajun Wu\",\"doi\":\"10.1093/pasj/psad078\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Isotopic ratios are good tools for probing stellar nucleosynthesis and chemical evolution. We perform high-sensitivity mapping observations of the J = 7–6 rotational transitions of OCS, OC34S, O13CS, and OC33S toward the Galactic Center giant molecular cloud Sagittarius B2 with the IRAM 30 m telescope. Positions with optically thin and uncontaminated lines are chosen to determine the sulfur isotope ratios. A 32S/34S ratio of 17.1 ± 0.9 was derived with OCS and OC34S lines, while a 34S/33S ratio of 6.8 ± 1.9 was derived directly from the integrated intensity ratio of OC34S and OC33S. With independent and accurate measurements of the 32S/34S ratio, our results confirm the termination of the decreasing trend of 32S/34S ratios toward the Galactic Center, suggesting a drop in the production of massive stars at the Galactic Center.\",\"PeriodicalId\":20733,\"journal\":{\"name\":\"Publications of the Astronomical Society of Japan\",\"volume\":\"12 5\",\"pages\":\"\"},\"PeriodicalIF\":2.2000,\"publicationDate\":\"2023-12-04\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Publications of the Astronomical Society of Japan\",\"FirstCategoryId\":\"101\",\"ListUrlMain\":\"https://doi.org/10.1093/pasj/psad078\",\"RegionNum\":4,\"RegionCategory\":\"物理与天体物理\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"ASTRONOMY & ASTROPHYSICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Publications of the Astronomical Society of Japan","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.1093/pasj/psad078","RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ASTRONOMY & ASTROPHYSICS","Score":null,"Total":0}
Sulfur isotopes toward the extended envelope of Sagittarius B2 in the Galactic Center
Isotopic ratios are good tools for probing stellar nucleosynthesis and chemical evolution. We perform high-sensitivity mapping observations of the J = 7–6 rotational transitions of OCS, OC34S, O13CS, and OC33S toward the Galactic Center giant molecular cloud Sagittarius B2 with the IRAM 30 m telescope. Positions with optically thin and uncontaminated lines are chosen to determine the sulfur isotope ratios. A 32S/34S ratio of 17.1 ± 0.9 was derived with OCS and OC34S lines, while a 34S/33S ratio of 6.8 ± 1.9 was derived directly from the integrated intensity ratio of OC34S and OC33S. With independent and accurate measurements of the 32S/34S ratio, our results confirm the termination of the decreasing trend of 32S/34S ratios toward the Galactic Center, suggesting a drop in the production of massive stars at the Galactic Center.
期刊介绍:
Publications of the Astronomical Society of Japan (PASJ) publishes the results of original research in all aspects of astronomy, astrophysics, and fields closely related to them.