Observations of multiple NH3 transitions in W33
文献类型：期刊论文
| 作者 | Tursun, K.6,7 ; Henkel, C.4,5,7; Esimbek, J.3,7; Tang, X. D.3,7; Wilson, T. L.5; Malawi, A.4; Alkhuja, E.2,4; Wyrowski, F.5; Mauersberger, R.5; Immer, K.1,5
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| 刊名 | ASTRONOMY & ASTROPHYSICS
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| 出版日期 | 2022-01-27 |
| 卷号 | 658页码:29 |
| ISSN号 | 0004-6361 |
| 关键词 | masers ISM: clouds ISM: individual objects: W33 HII regions ISM: molecules radio lines: ISM |
| DOI | 10.1051/0004-6361/202141937 |
| 通讯作者 | Tursun, K.(kadirya@xao.ac.cn) |
| 英文摘要 | At a distance of 2.4 kpc, W33 is an outstanding massive and luminous 10 pc-sized star forming complex containing quiescent infrared dark clouds as well as highly active infrared bright cloud cores heated by young massive stars. We report measurements of ammonia (NH3) inversion lines in the frequency range 18-26 GHz obtained with the 40 '' resolution of the 100 m Effelsberg telescope. We detect the (J, K) = (1,1), (2,2), (3,3), (4,4), (5,5), (6,6), (2,1), and (3,2) transitions. There is a maser line in the (3,3) transition towards W33 Main. Brightness temperature and line shape indicate no significant variation during the last similar to 36 yr. We determined kinetic temperatures, column densities, and other physical properties of NH3 and the molecular clouds in W33. For the total-NH 3 column density inside 40 '' (0.5 pc) regions, we find 6.0 (+/- 2.1) x 10(14), 3.5 (+/- 0.1) x 10(15) , 3.4 (+/- 0.2) x 10(15), 3.1 (+/- 0.2) x 10(15), 2.8 (+/- 0.2) x 10(15), and 2.0 (+/- 0.2) x 10(15) cm(-2) at the peak positions of W33 Main, W33 A, W33 B, W33 Mainl, W33 A1, and W33 B1, respectively. W33 Main has a total-NH3 fractional abundance of 1.3 (+/- 0.1) x 10(-9) at the peak position. High values of 1.4 (+/- 0.3) x 10(-8), 1.6 (+/- 0.3) x 10(-8), 3.4 (+/- 0.5) x 10(-8), 1.6 (+/- 0.5) x 10(-8), and 4.0 (+/- 1.2) x 10(-8) are obtained at the central positions of W33 A, W33 B, W33 Mainl, W33 A1, and W33 B1. From this, we confirm the previously proposed variation in the evolutionary stages of the six W33 clumps and find that there is no hot core in the region approaching the extreme conditions encountered in W51-IRS2 or Sgr B2. The ortho-to-para-NH3 abundance ratios suggest that ammonia should have been formed in the gas phase or on dust grain mantles at kinetic temperatures of greater than or similar to 20 K. We determine kinetic temperatures only using NH3 (1,1) and (2,2), and from this we provide gas volume densities for the six main sources in the W33 region. With our new T-kin values, we find that our volume densities are similar to those estimated by Immer et al. (2014, A&A, 572, A63), suggesting that ammonia beam-filling factors are close to unity. |
| WOS关键词 | STAR-FORMING REGIONS ; H II REGIONS ; HOT AMMONIA ; DENSE CORES ; INFRARED OBSERVATIONS ; KINETIC TEMPERATURE ; INTERNAL STRUCTURE ; MOLECULAR CLOUD ; MASER EMISSION ; MASSIVE STARS |
| 资助项目 | National Natural Science foundation of China[11 433 008] ; National Natural Science foundation of China[11 903 070] ; National Natural Science foundation of China[11 973 076] ; National Natural Science foundation of China[12 173 075] ; Heaven Lake Hundred-Talent Program of Xinjiang Uygur Autonomous Region of China ; CAS Light of West China Program[2018-XBQNXZ-B-024] ; CAS Light of West China Program[2020-XBQNXZ017] ; Chinese Academy of Sciences President's International Fellowship Initiative for visiting scientists[2021VMA0009] ; Chinese Academy of Sciences President's International Fellowship Initiative for visiting scientists[2022VMA0018] ; NASA |
| WOS研究方向 | Astronomy & Astrophysics |
| 语种 | 英语 |
| 出版者 | EDP SCIENCES S A |
| WOS记录号 | WOS:000747425900012 |
| 资助机构 | National Natural Science foundation of China ; Heaven Lake Hundred-Talent Program of Xinjiang Uygur Autonomous Region of China ; CAS Light of West China Program ; Chinese Academy of Sciences President's International Fellowship Initiative for visiting scientists ; NASA |
| 源URL | [http://ir.xao.ac.cn/handle/45760611-7/4476]  |
| 专题 | 恒星形成与演化研究团组 新疆天文台_射电天文研究室 |
| 通讯作者 | Tursun, K. |
| 作者单位 | 1.Leiden Univ, Leiden Observ, POB 9513, NL-2300 RA Leiden, Netherlands 2.Univ Potsdam, Inst Phys & Astron, Karl Liebknecht Str 24-25, D-14476 Golm, Germany 3.Chinese Acad Sci, Key Lab Radio Astron, Urumqi 830011, Peoples R China 4.King Abdulaziz Univ, Astron Dept, POB 80203, Jeddah 21589, Saudi Arabia 5.Max Planck Inst Radioastron, Hugel 69, D-53121 Bonn, Germany 6.Univ Chinese Acad Sci, Beijing 100080, Peoples R China 7.Chinese Acad Sci, Xinjiang Astron Observ, Urumqi 830011, Peoples R China |
| 推荐引用方式 GB/T 7714 | Tursun, K.,Henkel, C.,Esimbek, J.,et al. Observations of multiple NH3 transitions in W33[J]. ASTRONOMY & ASTROPHYSICS,2022,658:29. |
| APA | Tursun, K..,Henkel, C..,Esimbek, J..,Tang, X. D..,Wilson, T. L..,...&Wu, G..(2022).Observations of multiple NH3 transitions in W33.ASTRONOMY & ASTROPHYSICS,658,29. |
| MLA | Tursun, K.,et al."Observations of multiple NH3 transitions in W33".ASTRONOMY & ASTROPHYSICS 658(2022):29. |
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来源：新疆天文台
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