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相关论文: Velocity Anisotropy as a Diagnostic of the Magneti…

200 篇论文

The interstellar turbulence is magnetized and thus anisotropic. The anisotropy of turbulent magnetic fields and velocities is imprinted in the related observables, rotation measures (RMs), and velocity centroids (VCs). This anisotropy…

星系天体物理 · 物理学 2021-04-07 Siyao Xu , Yue Hu

The dynamics of the interstellar medium (ISM) are strongly affected by turbulence, which shows increased anisotropy in the presence of a magnetic field. We expand upon the Esquivel & Lazarian method to estimate the Alfven Mach number using…

星系天体物理 · 物理学 2015-06-22 Blakesley Burkhart , A. Lazarian , I. C. Leao , J. R. de Medeiros , A. Esquivel

Magnetic turbulence is anisotropic as the directions of motion are constrained by the magnetic field. Such anisotropy can be observed in velocity centroids obtained from spectroscopic observations. We use magnetohydrodynamics (MHD)…

星系天体物理 · 物理学 2020-08-13 D. Hernández-Padilla , A. Esquivel , A. Lazarian , D. Pogosyan , D. Kandel , J. Cho

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…

星系天体物理 · 物理学 2017-02-22 Frank Otto , Weiguang Ji , Hua-bai Li

Probing magnetic fields in the interstellar medium (ISM) is notoriously challenging. Motivated by the modern theories of magnetohydrodynamic (MHD) turbulence and turbulence anisotropy, we introduce the Structure-Function Analysis (SFA) as a…

星系天体物理 · 物理学 2021-04-21 Yue Hu , Siyao Xu , A. Lazarian

Velocity anisotropy induced by MHD turbulence is investigated using computational simulations and molecular line observations of the Taurus molecular cloud. A new analysis method is presented to evaluate the degree and angle of velocity…

天体物理学 · 物理学 2009-11-13 Mark Heyer , Hao Gong , Eve Ostriker , Christopher Brunt

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

We investigate how observations of synchrotron intensity fluctuations can be used to probe the sonic and Alfv\'enic Mach numbers of interstellar turbulence, based on mock observations performed on simulations of magnetohydrodynamic…

星系天体物理 · 物理学 2016-05-04 C. A. Herron , Blakesley Burkhart , A. Lazarian , B. M. Gaensler , N. M. McClure-Griffiths

The rich structure that we observe in molecular clouds is due to the interplay between strong magnetic fields and supersonic (turbulent) velocity fluctuations. The velocity fluctuations interact with the magnetic field, causing it too to…

星系天体物理 · 物理学 2020-08-12 James R. Beattie , Christoph Federrath , Amit Seta

Since synchrotron polarization fluctuations are related to the fundamental properties of the magnetic field, we propose the polarization intensity variance to measure the Galactic interstellar medium (ISM) magnetization. We confirm the…

星系天体物理 · 物理学 2024-04-26 Ning-Ning Guo , Jian-Fu Zhang , Hua-Ping Xiao , Jungyeon Cho , Xue-Juan Yang

A higher-order multiscale analysis of spatial anisotropy in inertial range magnetohydrodynamic turbulence is presented using measurements from the STEREO spacecraft in fast ambient solar wind. We show for the first time that, when measuring…

空间物理 · 物理学 2014-03-05 K. T. Osman , K. H. Kiyani , S. C. Chapman , B. Hnat

Based on statistical analysis of synchrotron polarization intensity, we study the anisotropic properties of compressible magnetohydrodynamic (MHD) turbulence. The second-order normalized structure function, quadrupole ratio modulus and…

高能天体物理现象 · 物理学 2020-02-26 Ru-Yue Wang , Jian-Fu Zhang , Fu-Yuan Xiang

We review the use of velocity centroids statistics to recover information of interstellar turbulence from observations. Velocity centroids have been used for a long time now to retrieve information about the scaling properties of the…

星系天体物理 · 物理学 2009-01-23 A. Esquivel , A. Lazarian

We study the statistics of density for supersonic turbulence in a medium with magnetic pressure larger than the gaseous pressure. This study is motivated by molecular cloud research. Our simulations exhibit clumpy density structures, which…

天体物理学 · 物理学 2009-11-10 A. Beresnyak , A. Lazarian , J. Cho

Understanding turbulence within the Intracluster Medium (ICM) of galaxy clusters is pivotal for comprehending their evolution and dynamics. Employing 3D magnetohydrodynamic (MHD) simulations of galaxy cluster mergers, we examine the…

星系天体物理 · 物理学 2025-07-30 Yue Hu , Alex Lazarian , G. Brunetti , John A. ZuHone

Due to the inevitable accumulation of the observed information in the direction of the line of sight, it is difficult to measure the local magnetic field of MHD turbulence. However, the correct understanding of the local magnetic field is a…

高能天体物理现象 · 物理学 2020-05-27 Jian-Fu Zhang , Ke Hu , Jungyeon Cho , Alex Lazarian

The measure of the third-order structure function, Y, is employed in the solar wind to compute the cascade rate of turbulence. In the absence of a mean field B0=0, Y is expected to be isotropic (radial) and independent of the direction of…

太阳与恒星天体物理 · 物理学 2015-05-27 Andrea Verdini , Roland Grappin , Petr Hellinger , Simone Landi , Wolf-Christian Müller

Small-scale magnetic turbulence observed by the Cluster spacecraft in the plasma sheet is investigated by means of a wavelet estimator suitable for detecting distinct scaling characteristics even in noisy measurements. The spectral…

A well-known property of solar wind plasma turbulence is the observed anisotropy of the autocorrelations, or equivalently the spectra, of velocity and magnetic field fluctuations. Here we explore the related but apparently not well-studied…

Direct numerical simulations of decaying and forced magnetohydrodynamic (MHD) turbulence without and with mean magnetic field are analyzed by higher-order two-point statistics. The turbulence exhibits statistical anisotropy with respect to…

等离子体物理 · 物理学 2009-11-10 Wolf-Christian Mueller , Dieter Biskamp , Roland Grappin
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