A NEW METHOD FOR CONSTRAINING MOLECULAR CLOUD THICKNESS: A STUDY OF TAURUS, PERSEUS, AND OPHIUCHUS
文献类型：期刊论文
| 作者 | Qian, Lei1; Li, Di1,2,3 ; Offner, Stella4; Pan, Zhichen1
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| 刊名 | ASTROPHYSICAL JOURNAL
 |
| 出版日期 | 2015-09-20 |
| 卷号 | 811期号:1 |
| 关键词 | ISM: clouds ISM: molecules turbulence |
| 英文摘要 | The core velocity dispersion (CVD) is a potentially useful tool for studying the turbulent velocity field of molecular clouds. CVD is based on centroid velocities of dense gas clumps, thus is less prone to density fluctuation and reflects more directly the cloud velocity field. Prior work demonstrated that the Taurus molecular cloud CVD resembles the well-known Larson's linewidth-size relation of molecular clouds. In this work, we studied the dependence of the CVD on the line-of-sight thickness of molecular clouds, a quantity which cannot be measured by direct means. We produced a simple statistical model of cores within clouds and analyzed the CVD of a variety of hydrodynamical simulations. We show that the relation between the CVD and the 2D projected separation of cores (L-2D) is sensitive to the cloud thickness. When the cloud is thin, the index of the CVD-L-2D relation (. in the relation CVD similar to L-2D(gamma)) reflects the underlying energy spectrum (E(k) similar to k(-beta)) in that gamma similar to (beta -1)/2. The CVD-L-2D relation becomes flatter (gamma -> 0) for thicker clouds. We used this result to constrain the thicknesses of Taurus, Perseus, and Ophiuchus. We conclude that Taurus has a ratio of cloud depth to cloud length smaller than about 1/10-1/8, i.e., it is a sheet. A simple geometric model fit to the linewidth-size relation indicates that the Taurus cloud has a similar to 0.7 pc line-of-sight dimension. In contrast, Perseus and Ophiuchus are thicker and have ratios of cloud depth to cloud length larger than about 1/10-1/8. |
| 收录类别 | SCI |
| 语种 | 英语 |
| WOS记录号 | WOS:000363471600072 |
| 源URL | [http://ir.bao.ac.cn/handle/114a11/5545]  |
| 专题 | 国家天文台_射电天文研究部 |
| 作者单位 | 1.Chinese Acad Sci, Natl Astron Observ, Beijing 100012, Peoples R China 2.Chinese Acad Sci, Key Lab Radio Astron, Beijing 100012, Peoples R China 3.Space Sci Inst, Boulder, CO USA 4.Univ Massachusetts, Dept Astron, Amherst, MA 01003 USA |
| 推荐引用方式 GB/T 7714 | Qian, Lei,Li, Di,Offner, Stella,et al. A NEW METHOD FOR CONSTRAINING MOLECULAR CLOUD THICKNESS: A STUDY OF TAURUS, PERSEUS, AND OPHIUCHUS[J]. ASTROPHYSICAL JOURNAL,2015,811(1). |
| APA | Qian, Lei,Li, Di,Offner, Stella,&Pan, Zhichen.(2015).A NEW METHOD FOR CONSTRAINING MOLECULAR CLOUD THICKNESS: A STUDY OF TAURUS, PERSEUS, AND OPHIUCHUS.ASTROPHYSICAL JOURNAL,811(1). |
| MLA | Qian, Lei,et al."A NEW METHOD FOR CONSTRAINING MOLECULAR CLOUD THICKNESS: A STUDY OF TAURUS, PERSEUS, AND OPHIUCHUS".ASTROPHYSICAL JOURNAL 811.1(2015). |
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来源：国家天文台
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