中文
相关论文

相关论文: Tracing magnetic fields with spectroscopic channel…

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 alignment of striated intensity structures in thin neutral hydrogen (HI) spectroscopic channels with Galactic magnetic fields has been observed. However, the origin and nature of these striations are still debatable. Some studies…

星系天体物理 · 物理学 2023-07-05 Yue Hu , A. Lazarian , D. Alina , D. Pogosyan , Ka Wai Ho

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…

星系天体物理 · 物理学 2020-07-07 Yue Hu , A. 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

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

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

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…

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

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

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),…

星系天体物理 · 物理学 2024-01-15 Tyler Schmaltz , Yue Hu , A. Lazarian

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

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…

星系天体物理 · 物理学 2022-01-26 Mingrui Liu , Yue Hu , Alex Lazarian

Recent development of the velocity gradient technique shows the {\toreferee capability} of the technique in the way of tracing magnetic fields morphology in diffuse interstellar gas and molecular clouds. In this paper, we perform the…

星系天体物理 · 物理学 2023-02-01 Ka Wai Ho , Alex Lazarian

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

We use a set of magnetohydrodynamics (MHD) simulations of fully-developed (driven) turbulence to study the anisotropy in the velocity field that is induced by the presence of the magnetic field. In our models we study turbulence…

星系天体物理 · 物理学 2015-05-30 Alejandro Esquivel , Alex Lazarian

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…

星系天体物理 · 物理学 2024-10-28 Alex Lazarian , Ka Wai HO , Ka Ho Yuen , Ethan Vishniac

We study possibility of obtaining velocity spectra by studying turbulence in an optically thick medium using velocity centroids (VCs).We find that the regime of universal, i.e. independent of underlying turbulence statistics, fluctuations…

星系天体物理 · 物理学 2016-10-12 D. Kandel , A. Lazarian , D. Pogosyan

Diffuse striations in molecular clouds are preferentially aligned with local magnetic fields whereas dense filaments tend to be perpendicular to them. When and why this transition occurs remain uncertain. To explore the physics behind this…

星系天体物理 · 物理学 2016-10-05 Che-Yu Chen , Patrick K. King , Zhi-Yun Li

The strengths of magnetic fields in interstellar gas clouds are obtained through observations of the circular polarization of spectral line radiation. Irregularities in this magnetic field may be present due to turbulence, waves or perhaps…

天体物理学 · 物理学 2009-10-31 W. D. Watson , D. S. Wiebe , R. M. Crutcher

Magnetic fields and turbulence are fundamental to the evolution of galaxies, yet their precise measurement and analysis present significant challenges. The recently developed Velocity Gradient Technique (VGT), which capitalizes on the…

星系天体物理 · 物理学 2025-03-07 Yue Hu , Joseph Whittingham , A. Lazarian , Christoph Pfrommer , Siyao Xu , Thomas Berlok