English
Related papers

Related papers: Studying Anisotropy of Compressible Magnetohydrody…

200 papers

Radio-wave scintillation observations reveal a nearly Kolmogorov spectrum of density fluctuations in the ionized interstellar medium. Although this density spectrum is suggestive of turbulence, no theory relevant to its interpretation…

Astrophysics · Physics 2009-11-06 Yoram Lithwick , Peter Goldreich

A heuristic model is given for anisotropic magnetohydrodynamics (MHD) turbulence in the presence of a uniform external magnetic field $B_0 {\bf {\hat e}_{\pa}}$. The model is valid for both moderate and strong $B_0$ and is able to describe…

Plasma Physics · Physics 2009-11-11 Sebastien Galtier , Annick Pouquet , Andre Mangeney

We present a linear analysis of inviscid, incompressible, magnetohydrodynamic (MHD) shallow water systems. In spherical geometry, a generic property of such systems is the existence of five wave modes. Three of them (two magneto-Poincare…

High Energy Astrophysical Phenomena · Physics 2015-05-13 Kevin Heng , Anatoly Spitkovsky

We perform direct 3-dimensional numerical simulations for magnetohydrodynamic (MHD) turbulence in a periodic box of size $2\pi$ threaded by strong uniform magnetic fields. We use a pseudo-spectral code with hyperviscosity and…

Astrophysics · Physics 2009-10-31 Jungyeon Cho , Ethan T. Vishniac

We present a detailed study of localised magnetohydrodynamical (MHD) instabilities occuring in two--dimensional magnetized accretion disks. We model axisymmetric MHD disk tori, and solve the equations governing a two--dimensional magnetized…

Astrophysics · Physics 2011-07-08 J. W. S. Blokland , R. Keppens , J. P. Goedbloed

In this paper, we report our detailed analysis of the new strong-coupling regime between Alfv\'en and fast modes in Poynting-dominated plasma turbulence, reported in our previous work Takamoto & Lazarian (2016), which is an important effect…

High Energy Astrophysical Phenomena · Physics 2017-10-18 Makoto Takamoto , Alexandre Lazarian

We summarise basic properties of MHD turbulence. First, MHD turbulence is not so messy as it is believed. In fact, the notion of strong non-linear coupling of compressible and incompressible motions along MHD cascade is not tenable. Alfven,…

Astrophysics · Physics 2007-05-23 A. Lazarian , A. Beresnyak

The first estimation of the energy cascade rate ${|\epsilon_C|}$ of magnetosheath turbulence is obtained using the CLUSTER and THEMIS spacecraft data and an exact law of compressible isothermal magnetohydrodynamics turbulence.…

Space Physics · Physics 2018-02-07 Lina Hadid , Fouad Sahraoui , Sebastien Galtier , Shiyong Huang

When magnetic energy density is much larger than that of matter, as in pulsar/black hole magnetospheres, the medium becomes force-free and we need relativity to describe it. As in non-relativistic magnetohydrodynamics (MHD), Alfv\'enic MHD…

High Energy Astrophysical Phenomena · Physics 2015-06-18 Jungyeon Cho , A. Lazarian

Three-dimensional direct numerical simulations (DNS) are implemented to investigate the energy cascade rate in compressible isothermal magnetohydrodynamic (MHD) turbulence. Utilizing an exact law derived from the K\'arm\'an-Howarth…

We present numerical simulations of electron magnetohydrodynamic (EMHD) and electron reduced MHD (ERMHD) turbulence. Comparing scaling relations, we find that both EMHD and ERMHD turbulence show similar spectra and anisotropy. We develop…

Earth and Planetary Astrophysics · Physics 2009-07-24 Jungyeon Cho , A. Lazarian

We analyse the anisotropy of homogeneous turbulence in an electrically conducting fluid submitted to a uniform magnetic field, for low magnetic Reynolds number, in the quasi- static approximation. We interpret disagreeing previous…

Fluid Dynamics · Physics 2012-07-23 B. F. N. Favier , F. S. Godeferd , C. Cambon , A. Delache , W. J. T. Bos

The role of magnetic helicity is investigated in kinetic Alfv\'en wave and oblique whistler turbulence in presence of a relatively intense external magnetic field $b_0 {\bf e_\parallel}$. In this situation, turbulence is strongly…

Solar and Stellar Astrophysics · Physics 2019-02-20 S. Galtier , R. Meyrand

We present a quantitative estimate of the anisotropic power and scaling of magnetic field fluctuations in inertial range magnetohydrodynamic turbulence, using a novel wavelet technique applied to spacecraft measurements in the solar wind.…

Plasma Physics · Physics 2009-11-13 T. S. Horbury , M. A. Forman , S. Oughton

Many astrophysical fluids are magnetized and turbulent. Such fluids can be often described by magnetohydrodynamics (MHD). In this review, we mainly consider MHD turbulence with a strong mean magnetic field whose energy density is greater…

High Energy Astrophysical Phenomena · Physics 2026-02-25 Jungyeon Cho

We discuss magnetic pressure and density fluctuations in strongly turbulent isothermal MHD flows in "1+2/3" dimensions. We first consider "simple" nonlinear MHD waves, which allow us show that the slow and fast modes have different…

Astrophysics · Physics 2007-05-23 Thierry Passot , Enrique Vazquez-Semadeni

Pressure anisotropy can strongly influence the dynamics of weakly collisional, high-beta plasmas, but its effects are missed by standard magnetohydrodynamics (MHD). Small changes to the magnetic-field strength generate large…

High Energy Astrophysical Phenomena · Physics 2023-07-10 Jonathan Squire , Matthew W Kunz , Lev Arzamasskiy , Zade Johnston , Eliot Quataert , Alexander A Schekochihin

Magnetohydrodynamic(MHD) turbulence displays velocity anisotropies which reflect the direction of the magnetic field. This anisotropy has led to the development of a number of statistical techniques for studying magnetic fields in the…

We study the statistics of density for supersonic turbulence in a medium with magnetic pressure larger than the gaseous pressure. This study is motivated by molecular cloud research. Our simulations exhibit clumpy density structures, which…

Astrophysics · Physics 2009-11-10 A. Beresnyak , A. Lazarian , J. Cho

Accretion disks are likely threaded by external vertical magnetic flux, which enhances the level of turbulence via the magnetorotational instability (MRI). Using shearing-box simulations, we find that such external magnetic flux also…

High Energy Astrophysical Phenomena · Physics 2015-06-22 Xue-Ning Bai , James M. Stone