KMS of Xinjiang Astronomical Observatory, CAS
| Discovery of non-metastable ammonia masers in Sagittarius B2 | |
Yan, Y. T.1; Henkel, C.1,2,3 ; Menten, K. M.1; Gong, Y.1; Nguyen, H.1; Ott, J.4; Ginsburg, A.5; Wilson, T. L.1; Brunthaler, A.1; Belloche, A.1; Zhang, J. S.6; Budaiev, N.5; Jeff, D.5
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| 2022-10-19 | |
| Source Publication | ASTRONOMY & ASTROPHYSICS
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| ISSN | 0004-6361 |
| Volume | 666Pages:L15 |
| Contribution Rank | 3 |
| Abstract | We report the discovery of widespread maser emission in non-metastable inversion transitions of NH3 toward various parts of the Sagittarius B2 molecular cloud and star-forming region complex. We detect masers in the J, K = (6, 3), (7,4), (8,5), (9,6), and (10,7) transitions toward Sgr B2(M) and Sgr B2(N), an NH3 (6,3) maser in Sgr B2(NS), and NH3 (7,4), (9,6), and (10,7) masers in Sgr B2(S). With the high angular resolution data of the Karl G. Jansky Very Large Array (JVLA) in the A-configuration, we identify 18 maser spots. Nine maser spots arise from Sgr B2(N), one from Sgr B2(NS), five from Sgr B2(M), and three in Sgr B2(S). Compared to our Effelsberg single-dish data, the JVLA data indicate no missing flux. The detected maser spots are not resolved by our JVLA observations. Lower limits to the brightness temperature are >3000 K and reach up to several 10(5) K, manifesting the lines' maser nature. In view of the masers' velocity differences with respect to adjacent hot molecular cores and/or UCH II regions, it is argued that all the measured ammonia maser lines may be associated with shocks caused either by outflows or by the expansion of UCH II regions. Overall, Sgr B2 is unique in that it allows us to measure many NH3 masers simultaneously, which may be essential in order to elucidate their thus far poorly understood origin and excitation. |
| Keyword | masers ISM: clouds ISM: individual objects: Sgr B2 HII regions radio lines: ISM |
| DOI | 10.1051/0004-6361/202245024 |
| Indexed By | SCI |
| Language | 英语 |
| WOS Keyword | STAR-FORMING REGION ; GALACTIC-CENTER ; FORMALDEHYDE MASERS ; SIO MASERS ; EMISSION ; LINE ; POSITIONS ; ENVELOPE ; B2(N) |
| Funding Project | China Scholarship Council (CSC) ; Max-Planck-Institut fur Radioastronomie (MPIfR) |
| WOS Research Area | Astronomy & Astrophysics |
| WOS Subject | Astronomy & Astrophysics |
| WOS ID | WOS:000869898200010 |
| Publisher | EDP SCIENCES S A |
| Funding Organization | China Scholarship Council (CSC) ; Max-Planck-Institut fur Radioastronomie (MPIfR) |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.xao.ac.cn/handle/45760611-7/4940 |
| Collection | 中国科学院新疆天文台 射电天文研究室_恒星形成与演化研究团组 |
| Corresponding Author | Yan, Y. T. |
| Affiliation | 1.Max Planck Inst Radioastron, Hugel 69, D-53121 Bonn, Germany 2.King Abdulaziz Univ, Fac Sci, Astron Dept, POB 80203, Jeddah 21589, Saudi Arabia 3.Chinese Acad Sci, Xinjiang Astron Observ, Urumqi 830011, Peoples R China 4.Natl Radio Astron Observ, 520 Edgemont Rd, Charlottesville, VA 22903 USA 5.Univ Florida, Dept Astron, POB 112055, Gainesville, FL 32611 USA 6.Guangzhou Univ, Ctr Astrophys, Guangzhou 510006, Peoples R China |
| Recommended Citation GB/T 7714 | Yan, Y. T.,Henkel, C.,Menten, K. M.,et al. Discovery of non-metastable ammonia masers in Sagittarius B2[J]. ASTRONOMY & ASTROPHYSICS,2022,666:L15. |
| APA | Yan, Y. T..,Henkel, C..,Menten, K. M..,Gong, Y..,Nguyen, H..,...&Jeff, D..(2022).Discovery of non-metastable ammonia masers in Sagittarius B2.ASTRONOMY & ASTROPHYSICS,666,L15. |
| MLA | Yan, Y. T.,et al."Discovery of non-metastable ammonia masers in Sagittarius B2".ASTRONOMY & ASTROPHYSICS 666(2022):L15. |
| Files in This Item: | ||||||
| File Name/Size | DocType | Version | Access | License | ||
| Yan-2022-Discovery o（3372KB） | 期刊论文 | 作者接受稿 | 开放获取 | CC BY-NC-SA | View Application Full Text | |
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