ISOTOPIC RATIOS OF O-18/O-17 IN THE GALACTIC CENTRAL REGION

doi:10.1088/0067-0049/219/2/28

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	ISOTOPIC RATIOS OF O-18/O-17 IN THE GALACTIC CENTRAL REGION
	Zhang, J. S.7; Sun, L. L.7; Riquelme, D.6; Henkel, C.5,6; Lu, D. R.1; Zhang, Y.4; Wang, J. Z.3; Wang, M.2; Li, J.3
刊名	ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
	2015-08-01
卷号	219 期号:2 页码:12
关键词	Galaxy: center ISM: abundances ISM: molecules radio lines: ISM
ISSN号	0067-0049
DOI	10.1088/0067-0049/219/2/28
英文摘要	The O-18/O-17 isotopic ratio of oxygen is a crucial measure of the secular enrichment of the interstellar medium by ejecta from high-mass versus intermediate-mass stars. So far, however, there is a lack of data, particularly from the Galactic center (GC) region. Therefore, we have mapped typical molecular clouds in this region in the J = 1-0 lines of (CO)-O-18 and (CO)-O-17 with the Delingha 13.7 m telescope (DLH). Complementary pointed observations toward selected positions throughout the GC region were obtained with the IRAM 30 m and Mopra 22 m telescopes. (CO)-O-18/(CO)-O-17 abundance ratios reflecting the O-18/O-17 isotope ratios were obtained from integrated intensity ratios of (CO)-O-18 and (CO)-O-17. For the first time, (CO)-O-18/(CO)-O-17 abundance ratios are determined for Sgr C (V similar to-58 km s(-1)), Sgr D (V similar to 80 km s(-1)), and the 1 degrees.3 complex (V similar to 80 km s(-1)). Through our mapping observations, abundance ratios are also obtained for Sgr A (similar to 0 and similar to 50 km s(-1) component) and Sgr B2 (similar to 60 km s(-1)), which are consistent with the results from previous single-point observations. Our frequency-corrected abundance ratios of the GC clouds range from 2.58 +/- 0.07 (Sgr D, V similar to 80 km s(-1), DLH) to 3.54 +/- 0.12 (Sgr A, similar to 50 km s(-1)). In addition, strong narrow components (line width less than 5 km s(-1)) from the foreground clouds are detected toward Sgr D (-18 km s(-1)), the 1 degrees.3 complex (-18 km s(-1)), and M+ 5.3-0.3 (22 km s(-1)), with a larger abundance ratio around 4.0. Our results show a clear trend of lower (CO)-O-18/(CO)-O-17 abundance ratios toward the GC region relative to molecular clouds in the Galactic disk. Furthermore, even inside the GC region, ratios appear not to be uniform. The low GC values are consistent with an inside-out formation scenario for our Galaxy.
资助项目	China Ministry of Science and Technology under State Key Development Program for Basic Research[2012CB821800] ; Natural Science Foundation of China[11178009] ; Natural Science Foundation of China[11473007] ; Research Grants Council of the Hong Kong[HKU7073/11P] ; Research Grants Council of the Hong Kong[HKU7062/13P]
WOS研究方向	Astronomy & Astrophysics
语种	英语
出版者	IOP PUBLISHING LTD
WOS记录号	WOS:000361876600014
内容类型	期刊论文
源URL	[http://119.78.226.72/handle/331011/32912]
专题	中国科学院上海天文台
通讯作者	Zhang, J. S.
作者单位	1.Purple Mt Observ, Qinghai Stn, Delingha 817000, Peoples R China 2.Chinese Acad Sci, Purple Mt Observ, Nanjing 210008, Jiangsu, Peoples R China 3.Chinese Acad Sci, Shanghai Astron Observ, Shanghai 200030, Peoples R China 4.Univ Hong Kong, Dept Phys, Hong Kong, Hong Kong, Peoples R China 5.King Abdulaziz Univ, Dept Astron, Jeddah 21589, Saudi Arabia 6.Max Planck Inst Radioastron, D-53121 Bonn, Germany 7.GuangZhou Univ, Ctr Astrophys, Guangzhou 510006, Guangdong, Peoples R China
推荐引用方式 GB/T 7714	Zhang, J. S.,Sun, L. L.,Riquelme, D.,et al. ISOTOPIC RATIOS OF O-18/O-17 IN THE GALACTIC CENTRAL REGION[J]. ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES,2015,219(2):12.
APA	Zhang, J. S..,Sun, L. L..,Riquelme, D..,Henkel, C..,Lu, D. R..,...&Li, J..(2015).ISOTOPIC RATIOS OF O-18/O-17 IN THE GALACTIC CENTRAL REGION.ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES,219(2),12.
MLA	Zhang, J. S.,et al."ISOTOPIC RATIOS OF O-18/O-17 IN THE GALACTIC CENTRAL REGION".ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES 219.2(2015):12.