Institutional Repository of Radio Astronomy Research Laboratory
| Velocity Anisotropy in Self-gravitating Molecular Clouds. I. Simulation | |
Otto, Frank1; Ji, Weiguang1,2 ; Li, Hua-bai1
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| 2017-02-01 | |
| Source Publication | Astrophysical Journal
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| ISSN | 0004-637X |
| Volume | 836Issue:1Pages:1495 |
| Contribution Rank | 2 |
| Abstract | The complex interplay between turbulence, magnetic fields, and self-gravity leads to the formation of molecular clouds out of the diffuse interstellar medium (ISM). One avenue of studying this interplay is by analyzing statistical features derived from observations, where the interpretation of these features is greatly facilitated by comparisons with numerical simulations. Here we focus on the statistical anisotropy present in synthetic maps of velocity centroid data, which we derive from three-dimensional magnetohydrodynamic simulations of a turbulent, magnetized, self-gravitating patch of ISM. We study how the orientation and magnitude of the velocity anisotropy correlate with the magnetic field and with the structures generated by gravitational collapse. Motivated by recent observational constraints, our simulations focus on the supersonic (sonic Mach number M approximate to 2-17) but sub-to trans-alfvenic (alfvenic Mach number. M-.A approximate to 0.2-1.2) turbulence regime, and we consider clouds that are barely to mildly magnetically supercritical (mass-to-flux ratio equal to once or twice the critical value). Additionally we explore the impact of the turbulence driving mechanism (solenoidal or compressive) on the velocity anisotropy. While we confirm previous findings that the velocity anisotropy generally aligns well with the plane-of-sky magnetic field, our inclusion of the effects of self-gravity reveals that in regions of higher column density, the velocity anisotropy may be destroyed or even reoriented to align with the gravitationally formed structures. We provide evidence that this effect is not necessarily due to the increase of. A inside the high-density regions. |
| Keyword | gravitation ISM: kinematics and dynamics ISM: magnetic fields ISM: structure magnetohydrodynamics (MHD) turbulence compressible magnetohydrodynamic turbulence magnetic-field alfvenic turbulence interstellar-medium dissipation statistics Astronomy & Astrophysics |
| Subtype | Article |
| DOI | 10.3847/1538-4357/836/1/95 |
| URL | 查看原文 |
| Indexed By | SCI |
| Language | 英语 |
| WOS ID | WOS:000397304500047 |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.xao.ac.cn/handle/45760611-7/3242 |
| Collection | 射电天文研究室_恒星形成与演化研究团组 |
| Affiliation | 1.Department of Physics, The Chinese University of Hong Kong, Sha Tin, N.T., Hong Kong; 2.Xinjiang Astronomical Observatory, Urumqi, Xinjiang, China |
| Recommended Citation GB/T 7714 | Otto, Frank,Ji, Weiguang,Li, Hua-bai. Velocity Anisotropy in Self-gravitating Molecular Clouds. I. Simulation[J]. Astrophysical Journal,2017,836(1):1495. |
| APA | Otto, Frank,Ji, Weiguang,&Li, Hua-bai.(2017).Velocity Anisotropy in Self-gravitating Molecular Clouds. I. Simulation.Astrophysical Journal,836(1),1495. |
| MLA | Otto, Frank,et al."Velocity Anisotropy in Self-gravitating Molecular Clouds. I. Simulation".Astrophysical Journal 836.1(2017):1495. |
| Files in This Item: | ||||||
| File Name/Size | DocType | Version | Access | License | ||
| Otto-2017-Velocity A（2263KB） | 期刊论文 | 出版稿 | 开放获取 | CC BY-NC-SA | View Application Full Text | |
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