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相关论文: Tracing interstellar magnetic field using velocity…

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We show that local directional alignment of the velocity and magnetic field fluctuations occurs rapidly in magnetohydrodynamics for a variety of parameters. This is observed both in direct numerical simulations and in solar wind data. The…

天体物理学 · 物理学 2008-11-26 W. H. Matthaeus , A. Pouquet , P. D. Mininni , P. Dmitruk , B. Breech

Magnetic fields in the intracluster medium (ICM) affect the structure and the evolution of galaxy clusters. However, their properties are largely unknown, and measuring magnetic fields in galaxy clusters is challenging, especially on…

星系天体物理 · 物理学 2020-10-14 Yue Hu , A. Lazarian , Yuan Li , Irina Zhuravleva , Marie-Lou Gendron-Marsolais

We study the magnetic field structures in six giant filaments associated with the spiral arms of the Milky Way by applying the Velocity Gradient technique (VGT) to the 13CO spectroscopic data from GRS, Fugin, and SEDIGSM surveys. Compared…

Measuring magnetic fields in the interstellar medium and obtaining their distribution along line-of-sight is very challenging with the traditional techniques. The Velocity Gradient Technique (VGT), which utilizes anisotropy of…

星系天体物理 · 物理学 2022-04-27 Yue Hu , A. Lazarian , Q. Daniel Wang

Emission in spectral lines can provide unique information on interstellar turbulence. Doppler shifts due to supersonic motions contain information on turbulent velocity field which is otherwise difficult to measure. However, the problem of…

天体物理学 · 物理学 2016-08-30 A. Lazarian

Magnetohydrodynamic (MHD) turbulence plays a critical role in many key astrophysical processes such as star formation, acceleration of cosmic rays, and heat conduction. However, its properties are still poorly understood. We explore how to…

高能天体物理现象 · 物理学 2024-10-30 Ru-Yue Wang , Jian-Fu Zhang , Fang Lu , Fu-Yuan Xiang

Turbulence is the most common state of astrophysical flows. In typical astrophysical fluids, turbulence is accompanied by strong magnetic fields, which has a large impact on the dynamics of the turbulent cascade. Recently, there has been a…

天体物理学 · 物理学 2011-05-10 Jungyeon Cho , A. Lazarian , Ethan Vishniac

Direct measurements of three-dimensional magnetic fields in the interstellar medium (ISM) are not achievable. However, the anisotropic nature of magnetohydrodynamic (MHD) turbulence provides a novel way of tracing the magnetic fields.…

星系天体物理 · 物理学 2021-07-14 Yue Hu , A. Lazarian , Siyao Xu

Magnetic fields play a crucial role in star formation, yet tracing them becomes particularly challenging, especially in the presence of outflow feedback in protostellar systems. We targeted the star-forming region L1551, notable for its…

星系天体物理 · 物理学 2024-03-26 Mingrui Liu , Yue Hu , Alex Lazarian

Based on the theoretical description of Position-Position-Velocity(PPV) statistics in Lazarian & Pogosyan(2000), we introduce a new technique called the Velocity Decomposition Algorithm(VDA) in separating the PPV fluctuations arising from…

星系天体物理 · 物理学 2021-04-14 Ka Ho Yuen , Ka Wai Ho , Alex Lazarian

We present a method for determining directions of magnetic field vectors in a spiral galaxy using two synchrotron polarization maps, an optical image, and a velocity field. The orientation of the transverse magnetic field is determined with…

星系天体物理 · 物理学 2019-02-18 Hiroyuki Nakanishi , Kohei Kurahara , Kenta Anraku

MHD Turbulence is a critical component of the current paradigms of star formation, particle transport, magnetic reconnection and evolution of the ISM, to name just a few. Progress on this difficult subject is made via numerical simulations…

星系天体物理 · 物理学 2015-05-27 Blakesley Burkhart , Alex Lazarian

Magnetic field are transported and tangled by turbulence, even as they lose identity due to nonideal or resistive effects. On balance field lines undergo stretch-twist-fold processes. The curvature field, a scalar that measures the tangling…

Turbulence simulation codes can exploit the flute-like nature of plasma turbulence to reduce the effective number of degrees of freedom necessary to represent fluctuations. This can be achieved by employing magnetic coordinates of which one…

等离子体物理 · 物理学 2015-05-18 M. A. Ottaviani

Parsec-scale multi-wavelength VLBA polarization observations can be used to study the magnetic-field structures of Active Galactic Nuclei (AGN) based on Faraday Rotation (FR) gradients. A number of transverse FR gradients have been found,…

宇宙学与河外天体物理 · 物理学 2009-05-15 Mehreen Mahmud , Denise C. Gabuzda

The central molecular zone (CMZ) plays an essential role in regulating the nuclear ecosystem of our Galaxy. To get an insight into the magnetic fields of the CMZ, we employ the Gradient Technique (GT), which is rooted in the anisotropy of…

星系天体物理 · 物理学 2022-02-09 Yue Hu , A. Lazarian , Q. Daniel Wang

Magnetic fields and their dynamical interplay with matter in galaxy clusters contribute to the physical properties and evolution of the intracluster medium. However, the current understanding of the origin and properties of cluster magnetic…

宇宙学与河外天体物理 · 物理学 2024-02-12 Yue Hu , C. Stuardi , A. Lazarian , G. Brunetti , A. Bonafede , Ka Wai Ho

We investigate the appearance of a low-frequency 1/f magnetic spectrum in three-dimensional incompressible magnetohydrodynamic turbulence using direct numerical simulations and virtual spacecraft sampling. Our goal is to determine how the…

太阳与恒星天体物理 · 物理学 2026-05-28 Maia Brodiano , Facundo Pugliese , Nahuel Andrés , Pablo Dmitruk

Motivated by recent analytic predictions, we report numerical evidence showing that in driven incompressible magnetohydrodynamic turbulence the magnetic- and velocity-field fluctuations locally tend to align the directions of their…

天体物理学 · 物理学 2007-05-23 Joanne Mason , Fausto Cattaneo , Stanislav Boldyrev

We briefly review the recent developments in magnetohydrodynamics, which in particular deal with the evolution of magnetic fields in turbulent plasmas. We especially emphasize (i) the necessity of renormalizing equations of motion in…

等离子体物理 · 物理学 2025-05-01 Amir Jafari