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Related papers: Statistics of Centroids of Velocity

200 papers

A number of experiments for measuring anisotropies of the Cosmic Microwave Background use scanning strategies in which temperature fluctuations are measured along circular scans on the sky. It is possible, from a large number of such…

Astrophysics · Physics 2009-10-30 J. Delabrouille , K. M. Górski , E. Hivon

In this paper we test the results of a recent analytical study by Lazarian and Pogosyan, on the statistics of emissivity in velocity channel maps, in the case of realistic density and velocity fields obtained from numerical simulations of…

Astrophysics · Physics 2009-11-06 Alex Lazarian , Dmitri Pogosyan , Enrique Vazquez-Semadeni , Barbara Pichardo

We study the statistical properties of orientation and rotation dynamics of elliptical tracer particles in two-dimensional, homogeneous and isotropic turbulence by direct numerical simulations. We consider both the cases in which the…

Fluid Dynamics · Physics 2014-03-19 Anupam Gupta , Dario Vincenzi , Rahul Pandit

We investigate how observations of synchrotron intensity fluctuations can be used to probe the sonic and Alfv\'enic Mach numbers of interstellar turbulence, based on mock observations performed on simulations of magnetohydrodynamic…

Astrophysics of Galaxies · Physics 2016-05-04 C. A. Herron , Blakesley Burkhart , A. Lazarian , B. M. Gaensler , N. M. McClure-Griffiths

We present an overview of the Velocity Coordinate Spectrum (VCS), a new technique for studying astrophysical turbulence that utilizes the line-of-sight statistics of Doppler-broadened spectral lines. We consider the retrieval of turbulence…

Astrophysics of Galaxies · Physics 2009-02-03 D. Pogosyan , A. Lazarian

This paper summarises some of the recent progress that has been made in understanding astrophysical plasma turbulence in the solar wind, from in situ spacecraft observations. At large scales, where the turbulence is predominantly Alfvenic,…

Plasma Physics · Physics 2017-01-19 C. H. K. Chen

A general model for stationary, time-wise turbulent velocity is presented and discussed. This approach, inspired by modeling ideas of Barndorff-Nielsen and Schimgel, is coherent with the K41 hypothesis of local isotropy, and it allows us to…

Data Analysis, Statistics and Probability · Physics 2012-05-31 Vincenzo Ferrazzano , Claudia Klüppelberg

We present a statistical analysis of the two-point vorticity probability density of the vorticity field generated in the inverse cascade of stationary two-dimensional turbulence.

Fluid Dynamics · Physics 2012-12-12 R. Friedrich , M. Voßkuhle , O. Kamps , M. Wilczek

Weakly collisional space plasmas are rarely in local thermal equilibrium and often exhibit non-Maxwellian electron and ion velocity distributions that lead to the growth of microinstabilities, that is, enhanced electric and magnetic fields…

Stratified turbulence shows scale- and direction-dependent anisotropy and the coexistence of weak turbulence of internal gravity waves and strong turbulence of eddies. Straightforward application of standard analyses developed in isotropic…

Fluid Dynamics · Physics 2019-10-10 Naoto Yokoyama , Masanori Takaoka

We perform three-dimensional (3D) compressible MHD simulations over many dynamical times for an extended range of sonic and Alfven Mach numbers and analyze the statistics of 3D density and 2D column density, which include probability…

Astrophysics · Physics 2009-01-19 G. Kowal , A. Lazarian , A. Beresnyak

The statistical properties of turbulence are considered to be universal at sufficiently small length scales, i. e., independent of boundary conditions and large-scale forces acting on the fluid. Analyzing data from numerical simulations of…

Astrophysics · Physics 2008-12-18 Wolfram Schmidt , Christoph Federrath , Ralf Klessen

We study the observable properties of compressible MHD turbulence covering different turbulence regimes, based on synthetic synchrotron observations arising from 3D MHD numerical simulations. Using the synchrotron emissivity and intensity,…

High Energy Astrophysical Phenomena · Physics 2022-12-07 Ru-Yue Wang , Jian-Fu Zhang , Alex Lazarian , Hua-Ping Xiao , Fu-Yuan Xiang

Theoretical and observational studies on the turbulence of the interstellar medium developed fast in the past decades. The theory of supersonic magnetized turbulence, as well as the understanding of projection effects of observed…

Astrophysics of Galaxies · Physics 2015-05-18 D. Falceta-Goncalves , A. Lazarian , M. Houde

The orientation of small anisotropic particles settling in a turbulent fluid determines some essential properties of the suspension. We show that the orientation distribution of small heavy spheroids settling through turbulence can be…

Fluid Dynamics · Physics 2017-12-27 K. Gustavsson , J. Jucha , A. Naso , E. Lévêque , A. Pumir , B. Mehlig

When magnetohydrodynamic turbulence evolves in the presence of a large-scale mean magnetic field, an anisotropy develops relative to that preferred direction. The well-known tendency is to develop stronger gradients perpendicular to the…

Plasma Physics · Physics 2020-07-15 Rohit Chhiber , William H. Matthaeus , Sean Oughton , Tulasi N. Parashar

We derive formulae connecting the frequency variations in the spectrum of solar oscillations to the dynamical quantities that are expected to change over the solar activity cycle. This is done for both centroids and the asymmetric part of…

Astrophysics · Physics 2009-11-10 W. A. Dziembowski , P. R. Goode

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

Plasma turbulence is studied via direct numerical simulations in a two-dimensional spatial geometry. Using a hybrid Vlasov-Maxwell model, we investigate the possibility of a velocity-space cascade. A novel theory of space plasma turbulence…

Plasma Physics · Physics 2018-08-01 O. Pezzi , S. Servidio , D. Perrone , F. Valentini , L. Sorriso-Valvo , A. Greco , W. H. Matthaeus , P. Veltri

The peculiar velocities of galaxies distort the clustering pattern anisotropically in redshift space. This effect on the statistics of isodensity contours is examined by linear theory. The statistics considered in this paper are the three-…

Astrophysics · Physics 2016-08-30 Takahiko Matsubara
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