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Related papers: Velocity Gradients as a Tracer for Magnetic Fields

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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

We study the properties of sub-Alfvenic magnetohydrodynamic (MHD) turbulence, i.e., turbulence with Alfven Mach number $M_A=V_L/V_A<1$, where $V_L$ is the velocity at the injection scale and $V_A$ is the Alfven velocity. We demonstrate that…

Astrophysics of Galaxies · Physics 2024-10-28 Alex Lazarian , Ka Wai HO , Ka Ho Yuen , Ethan Vishniac

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

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…

Astrophysics · Physics 2008-11-26 W. H. Matthaeus , A. Pouquet , P. D. Mininni , P. Dmitruk , B. Breech

The atomic-to-molecular (HI-to-H$_2$) transition in photodissociation regions (PDRs) has been investigated over the last several decades through analytic and numerical modeling. However, classical PDR models typically assume uniform density…

Astrophysics of Galaxies · Physics 2021-01-06 Yue Hu , A. Lazarian , Shmuel Bialy

The Davis-Chandrasekhar-Fermi (DCF) method is widely used to indirectly estimate the magnetic field strength from the plane-of-sky field orientation. In this work, we present a set of 3D MHD simulations and synthetic polarization images…

Astrophysics of Galaxies · Physics 2021-10-04 Junhao Liu , Qizhou Zhang , Benoit Commercon , Valeska Valdivia , Anaelle Maury , Keping Qiu

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…

The mean plane-of-sky magnetic field strength is traditionally obtained from the combination of polarization and spectroscopic data using the Davis-Chandrasekhar-Fermi (DCF) technique. However, we identify the major problem of the DCF to be…

Astrophysics of Galaxies · Physics 2022-08-31 A. Lazarian , Ka Ho Yuen , Dmitri Pogosyan

We study a fundamental problem in computational chemistry known as molecular conformation generation, trying to predict stable 3D structures from 2D molecular graphs. Existing machine learning approaches usually first predict distances…

Machine Learning · Computer Science 2021-06-09 Chence Shi , Shitong Luo , Minkai Xu , Jian Tang

The Chandrasekhar-Fermi method is a powerful technique for estimating the strength of the mean magnetic field projected on the plane of the sky. In this paper, we present a technique for improving the Chandrasekhar-Fermi method, in which we…

Astrophysics of Galaxies · Physics 2016-04-20 Jungyeon Cho , Hyunju Yoo

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

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

Using advanced numerical magneto-hydrodynamic simulations of the magnetised solar photosphere, including non-grey radiative transport and a non-ideal equation of state, we analyse plasma motions in photospheric magnetic vortices. We…

Solar and Stellar Astrophysics · Physics 2015-06-17 S. Shelyag , P. S. Cally , A. Reid , M. Mathioudakis

The search for particle electric dipole moments (edm) represents a most promising way to search for physics beyond the standard model. A number of groups are planning a new generation of experiments using stored gases of various kinds. In…

Nuclear Experiment · Physics 2022-04-26 A. L. Barabanov , R. Golub , S. K. Lamoreaux

Measuring the 3D spatial distribution of magnetic fields in the interstellar medium and the intracluster medium is crucial yet challenging. The probing of 3D magnetic field's 3D distribution, including the field plane-of-sky orientation…

Astrophysics of Galaxies · Physics 2025-01-28 Yue Hu , Alex Lazarian

Based on the modern understanding of MHD turbulence theory, we propose a new method for measuring the spectral properties of magnetic turbulence by synchrotron polarization gradient analysis. Using synthetic polarization observational data,…

High Energy Astrophysical Phenomena · Physics 2025-05-08 Jianfu Zhang , Ziqi Liu

We investigate the alignment mechanism between the magnetic field and interstellar clouds formed by the collision of warm atomic gas. We find that the magnetic field, initially oriented parallel to the flow, is perturbed by a fast MHD…

Astrophysics of Galaxies · Physics 2025-02-26 Guido Granda-Muñoz , Enrique Vázquez-Semadeni , Gilberto C. Gómez

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

Alfv\'enic turbulence is an effective mechanism for particle acceleration in strongly magnetized, relativistic plasma. In this study, we investigate a scenario where turbulent plasma is influenced by a strong guide magnetic field, resulting…

Plasma Physics · Physics 2025-05-20 Cristian Vega , Stanislav Boldyrev , Vadim Roytershteyn

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.…

Astrophysics of Galaxies · Physics 2021-07-14 Yue Hu , A. Lazarian , Siyao Xu