Velocity Anisotropy in Self-gravitating Molecular Clouds. I. Simulation

doi:10.3847/1538-4357/836/1/95

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	Velocity Anisotropy in Self-gravitating Molecular Clouds. I. Simulation
	Otto, Frank 1; Ji, Weiguang1,2 ; Li, Hua-bai 1
刊名	Astrophysical Journal
	2017-02-01
卷号	836 期号:1 页码:1495
关键词	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
ISSN号	0004-637X
DOI	10.3847/1538-4357/836/1/95
产权排序	2
文献子类	Article
英文摘要	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.
URL标识	查看原文
语种	英语
WOS记录号	WOS:000397304500047
内容类型	期刊论文
源URL	[http://ir.xao.ac.cn/handle/45760611-7/3242]
专题	恒星形成与演化研究团组
作者单位	1.Department of Physics, The Chinese University of Hong Kong, Sha Tin, N.T., Hong Kong; 2.Xinjiang Astronomical Observatory, Urumqi, Xinjiang, China
推荐引用方式 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.