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相关论文: Tracing interstellar magnetic field using velocity…

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This paper studies how to employ synchrotron emission gradient techniques to reveal the properties of the magnetic field within the interstellar media. Based on data cubes of three-dimensional numerical simulations of magnetohydrodynamic…

高能天体物理现象 · 物理学 2020-01-08 Jian-Fu Zhang , Qian Liu , Alex Lazarian

On the basis of the modern understanding of MHD turbulence, we propose a new way of using synchrotron radiation, namely using synchrotron intensity gradients for tracing astrophysical magnetic fields. We successfully test the new technique…

星系天体物理 · 物理学 2018-03-21 A. Lazarian , Ka Ho Yuen , Hyeseung Lee , Jungyeon Cho

We test a new technique of studying magnetohydrodynamic (MHD) turbulence suggested by Lazarian \& Pogosyan, using synthetic synchrotron polarization observations. This paper focuses on a one-point statistics, which is termed the…

高能天体物理现象 · 物理学 2016-07-20 Jian-Fu Zhang , Alex Lazarian , Hyeseung Lee , Jungyeon Cho

Probing magnetic fields in Giant Molecular Clouds is often challenging. Fortunately, recently simulations show that analysis of velocity gradients (the Velocity Gradient Technique) can be used to map out the magnetic field morphology of…

星系天体物理 · 物理学 2019-11-06 Yue Hu , Ka Ho Yuen , A. Lazarian , Laura M. Fissel , P. A. Jones , M. R. Cunningham

Dust polarization orientations in molecular clouds often tend to be close to tangential to the Stokes $I$ dust continuum emission contours. The magnetic field and the emission gradient orientations, therefore, show some correlation. A…

星系天体物理 · 物理学 2015-06-03 Patrick M. Koch , Ya-Wen Tang , Paul T. P. Ho

The observations of fluctuations in the cosmic microwave background provide information about primordial inhomogeneities in the universe. However, the B-mode polarization of the inflationary gravitational wave is contaminated by the…

宇宙学与河外天体物理 · 物理学 2020-01-29 Yue Hu , Ka Ho Yuen , Alex Lazarian

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

In this study, we apply the Velocity Gradient Technique (VGT) to the merging Centaurus galaxy. We compare gradient maps derived from the PHANGS-ALMA survey using CO emission lines with magnetic field tracings from dust polarization data…

星系天体物理 · 物理学 2024-06-07 Quynh Lan Nguyen , Yue Hu , Alex Lazarian

We apply Velocity Channel Gradients (VChGs) and Reduced Velocity Centroids Gradients (RVCGs) to H I data (the LAB survey), obtaining the plane-of-sky component (POS) of the magnetic field as a function of the relative velocity. Assuming a…

星系天体物理 · 物理学 2019-06-13 Diego F. Gonzalez-Casanova , A. Lazarian

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

We study compressible MHD turbulence, which holds key to many astrophysical processes, including star formation and cosmic ray propagation. To account for the variations of the magnetic field in the strongly turbulent fluid we use wavelet…

星系天体物理 · 物理学 2015-05-18 Grzegorz Kowal , Alex Lazarian

Super-Alfv\'enic turbulence is widespread in astrophysical environments, including molecular clouds and the diffuse plasma of galaxy clusters. At large scales, magnetic fields play only a minor dynamical role; however, for sufficiently…

星系天体物理 · 物理学 2025-12-24 A. Lazarian , Yue Hu , D. Pogosyan

Tracing of the magnetic field with Velocity Gradient Technique (VGT) allows observers to probe magnetic field directions with spectroscopic data. In this paper, we employ the method of Principal Component Analysis (PCA) to extract the…

星系天体物理 · 物理学 2018-07-25 Yue Hu , Ka Ho Yuen , A. Lazarian

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

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

We use the results of magnetohydrodynamic (MHD) simulations to emulate spectroscopic observations and use maps of centroids to study their statistics. In order to assess under which circumstances the scaling properties of the velocity field…

天体物理学 · 物理学 2007-05-23 A. Esquivel , A. Lazarian

Considering the spatially separated polarization radiation and Faraday rotation regions to simulate complex interstellar media, we study synchrotron polarization gradient techniques' measurement capabilities. We explore how to trace the…

高能天体物理现象 · 物理学 2021-07-14 Ru-Yue Wang , Jian-Fu Zhang , Alex Lazarian , Hua-Ping Xiao , Fu-Yuan Xiang

It is well-known that magnetohydrodynamic (MHD) turbulence is ubiquitous in astrophysical environments. The correct understanding of the fundamental properties of MHD turbulence is a prerequisite for revealing many key astrophysical…

高能天体物理现象 · 物理学 2022-03-18 Jianfu Zhang , Ruyue Wang

Super-Alfvenic turbulence is important for many astrophysical objects, particularly galaxy clusters. In this paper, we explore the accuracy of Synchrotron Intensity Gradients (SIGs) and X-ray intensity gradients to map magnetic fields in…

星系天体物理 · 物理学 2024-12-04 Ka Wai Ho , Alex Lazarian

We study statistical properties of synchrotron polarization emitted from media with magnetohydrodynamic (MHD) turbulence. We use both synthetic and MHD turbulence simulation data for our studies. We obtain the spatial spectrum and its…

高能天体物理现象 · 物理学 2017-03-08 Hyeseung Lee , Alex Lazarian , Jungyeon Cho