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Related papers: 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…

High Energy Astrophysical Phenomena · Physics 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…

Astrophysics of Galaxies · Physics 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…

High Energy Astrophysical Phenomena · Physics 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…

Astrophysics of Galaxies · Physics 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…

Astrophysics of Galaxies · Physics 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…

Cosmology and Nongalactic Astrophysics · Physics 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…

Astrophysics of Galaxies · Physics 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…

Astrophysics of Galaxies · Physics 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…

Astrophysics of Galaxies · Physics 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)…

Astrophysics of Galaxies · Physics 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…

Astrophysics of Galaxies · Physics 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…

Astrophysics of Galaxies · Physics 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…

Astrophysics of Galaxies · Physics 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…

Astrophysics of Galaxies · Physics 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…

Astrophysics of Galaxies · Physics 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…

Astrophysics · Physics 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…

High Energy Astrophysical Phenomena · Physics 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…

High Energy Astrophysical Phenomena · Physics 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…

Astrophysics of Galaxies · Physics 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…

High Energy Astrophysical Phenomena · Physics 2017-03-08 Hyeseung Lee , Alex Lazarian , Jungyeon Cho