English
Related papers

Related papers: Distribution of velocity gradient orientations: Ma…

200 papers

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 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

Many machine learning problems can be seen as approximating a \textit{target} distribution using a \textit{particle} distribution by minimizing their statistical discrepancy. Wasserstein Gradient Flow can move particles along a path that…

Machine Learning · Statistics 2024-06-07 Song Liu , Jiahao Yu , Jack Simons , Mingxuan Yi , Mark Beaumont

We address the problem of studying interstellar turbulence using spectral line data. We find a criterion when the velocity centroids may provide trustworthy velocity statistics. To enhance the scope of centroids applications, we construct a…

Astrophysics · Physics 2009-11-07 A. Lazarian , A. Esquivel

In this paper, we aim to estimate the vertical gradients in the rotational velocity of the Galaxy. This is carried out in the framework of a global thin disc model approximation. The predicted gradient values coincide with the observed…

Astrophysics of Galaxies · Physics 2015-03-13 Joanna Jałocha , Łukasz Bratek , Marek Kutschera , Piotr Skindzier

The dynamics of the interstellar medium (ISM) are strongly affected by turbulence, which shows increased anisotropy in the presence of a magnetic field. We expand upon the Esquivel & Lazarian method to estimate the Alfven Mach number using…

Astrophysics of Galaxies · Physics 2015-06-22 Blakesley Burkhart , A. Lazarian , I. C. Leao , J. R. de Medeiros , A. Esquivel

The central molecular zone (CMZ) plays an essential role in regulating the nuclear ecosystem of our Galaxy. To get an insight into the magnetic fields of the CMZ, we employ the Gradient Technique (GT), which is rooted in the anisotropy of…

Astrophysics of Galaxies · Physics 2022-02-09 Yue Hu , A. Lazarian , Q. Daniel Wang

We present an elegant application of matterwave interferometry to the velocimetry of cold atoms whereby, in analogy to Fourier transform spectroscopy, the 1-D velocity distribution is manifest in the frequency domain of the interferometer…

Atomic Physics · Physics 2019-03-06 Max Carey , Jack Saywell , David Elcock , Mohammad Belal , Tim Freegarde

In this work we investigate the characteristics of the group velocity of obliquely propagating Alfv\'en waves in a dusty plasma typical of a stellar wind. The dispersion relation is derived with the aid of the kinetic theory for a…

Plasma Physics · Physics 2022-09-09 L. B. De Toni , R. Gaelzer , L. F. Ziebell

Interstellar medium is turbulent and this induces relative motions of dust grains. We calculate relative velocities of charged grains in a partially ionized magnetized gas. We account for anisotropy of magnetohydrodynamic (MHD) turbulence,…

Astrophysics · Physics 2009-11-07 A. Lazarian , Huirong Yan

Recent advances in understanding of magnetohydrodynamic (MHD) turbulence call for substantial revisions in the picture of cosmic ray transport. In this paper we use recently obtained scaling laws for MHD modes to calculate the scattering…

Astrophysics · Physics 2007-05-23 Huirong Yan , A. Lazarian

Magnetic fields play a crucial role in star formation, yet tracing them becomes particularly challenging, especially in the presence of outflow feedback in protostellar systems. We targeted the star-forming region L1551, notable for its…

Astrophysics of Galaxies · Physics 2024-03-26 Mingrui Liu , Yue Hu , Alex Lazarian

We have used integral field spectroscopy of a sample of six nearby (z~0.01-0.04) high star-formation rate (SFR~10-40 solar masses per year) galaxies to investigate the relationship between local velocity dispersion and star formation rate…

Astrophysics of Galaxies · Physics 2016-03-23 Mathew Varidel , Michael Pracy , Scott Croom , Matt Owers , Elaine Sadler

Turbulence and magnetic fields are components of the interstellar medium and are interconnected through plasma processes. In particular, the magnetic flux transport in the presence of magneto-hydrodynamic (MHD) turbulence is an essential…

High Energy Astrophysical Phenomena · Physics 2025-07-30 C. N. Koshikumo , R. Santos-Lima , M. V. del Valle , E. M. de Gouveia Dal Pino , G. Guerrero , A. Lazarian

The differential affine velocity estimator (DAVE) developed in Schuck (2006) for estimating velocities from line-of-sight magnetograms is modified to directly incorporate horizontal magnetic fields to produce a differential affine velocity…

Astrophysics · Physics 2009-11-13 P. W. Schuck

We have studied the propagation of inertial Alfv\'en waves through parallel gradients in the Alfv\'en speed using the Large Plasma Device at the University of California, Los Angeles. The reflection and transmission of Alfv\'en waves…

In this work, we explore the diversity of ionised gas kinematics (rotational velocity $v_{\phi}$ and velocity dispersion $\sigma_{\mathrm{g}}$) and gas-phase metallicity gradients at $0.1 \leq z \leq 2.5$ using a compiled data set of 74…

Astrophysics of Galaxies · Physics 2021-06-29 Piyush Sharda , Emily Wisnioski , Mark R. Krumholz , Christoph Federrath

One of the tools that can provide evidence about the existence of helical magnetic fields in AGN is the observation of rotation measure gradients across the jet. Such observations have been previously made successfully, proving that such…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 J. C. Algaba

Wu et al. (2009) suggested an empirical relation between the magnetic field strength along the line of sight (LOS) and the dispersion of Faraday rotation measure (RM) distribution in turbulent media with root-mean-square sonic Mach number…

Astrophysics of Galaxies · Physics 2014-03-03 Qingwen Wu , Jongsoo Kim , Dongsu Ryu

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