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Related papers: Velocity Gradients as a Tracer for Magnetic Fields

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The detection of primordial B-mode polarization is still challenging due to the relatively low amplitude compared to the galactic foregrounds. To remove the contribution from the foreground, a comprehensive picture of the galactic magnetic…

Astrophysics of Galaxies · Physics 2020-07-07 Yue Hu , A. Lazarian

Magnetic fields, while ubiquitous in many astrophysical environments, are challenging to measure observationally. Based on the properties of anisotropy of eddies in magnetized turbulence, the Velocity Gradient Technique is a method…

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

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

Magnetic fields are a defining yet enigmatic aspect of the interstellar medium (ISM), with their three-dimensional mapping posing a substantial challenge. In this study, we harness the innovative Velocity Gradient Technique (VGT),…

Astrophysics of Galaxies · Physics 2024-01-15 Tyler Schmaltz , Yue Hu , A. Lazarian

As a novel approach for tracing interstellar magnetic fields, the Velocity Gradient Technique (VGT) has been proven to be effective for probing magnetic fields in the diffuse interstellar medium (ISM). In this work, we verify the VGT in a…

Astrophysics of Galaxies · Physics 2022-01-26 Mingrui Liu , Yue Hu , Alex Lazarian

Star formation is a complex process that typically occurs in dense regions of molecular clouds mainly regulated by magnetic fields, magnetohydrodynamic (MHD) turbulence, and self-gravity. However, it remains a challenging endeavor to trace…

Astrophysics of Galaxies · Physics 2023-05-31 Tyler Schmaltz , Yue Hu , Alex Lazarian

The Davis-Chandrasekhar-Fermi (DCF) method is widely employed to estimate the mean magnetic field strength in astrophysical plasmas. In this study, we present a numerical investigation using the DCF method in conjunction with a promising…

Instrumentation and Methods for Astrophysics · Physics 2023-05-10 Parth Pavaskar , Huirong Yan , Jungyeon Cho

Magnetic fields play an important role in the evolution of molecular clouds and star formation. Using the Velocity Gradient Technique (VGT) model, we measured the magnetic field in Orion A using the 12CO, 13CO, and C18O (1-0) emission lines…

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…

Solar and Stellar Astrophysics · Physics 2026-05-28 Maia Brodiano , Facundo Pugliese , Nahuel Andrés , Pablo Dmitruk

We explore how the velocity gradient technique (VGT) can be applied to absorbing media in the case of$^{13}$CO 2-1 emission. The VGT is a new way to trace magnetic fields in the plane of the sky using only spectroscopic observations. We…

Astrophysics of Galaxies · Physics 2019-06-13 Diego F. González-Casanova , A. Lazarian , Blakesley Burkhart

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…

High Energy Astrophysical Phenomena · Physics 2020-05-27 Jian-Fu Zhang , Ke Hu , Jungyeon Cho , Alex Lazarian

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…

Astrophysics of Galaxies · Physics 2022-04-27 Yue Hu , A. Lazarian , Q. Daniel Wang

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

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…

Astrophysics of Galaxies · Physics 2019-02-18 Hiroyuki Nakanishi , Kohei Kurahara , Kenta Anraku

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

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

We report the first attempt to mode decomposition of the velocity field using wavelet transforms in the application to the magnetized turbulence analysis. We compare results of the separation with respect to the global and local mean…

Astrophysics · Physics 2007-05-23 Grzegorz Kowal , Alex Lazarian

Despite the rich observational results on interstellar magnetic fields in star-forming regions, it is still unclear how dynamically significant the magnetic fields are at varying physical scales, because direct measurement of the field…

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