English
Related papers

Related papers: Long-lived Magnetic-Tension-Driven Modes in a Mole…

200 papers

Intermittent large-scale high-shear flows are found to occur frequently and spontaneously in direct numerical simulations of statistically stationary turbulent Boussinesq magnetohydrodynamic (MHD) convection. The energetic steady-state of…

Solar and Stellar Astrophysics · Physics 2013-09-06 J. Pratt , A. Busse , W. -C. Mueller

Sub-mm observations of protoplanetary disks now approach the acuity needed to measure the turbulent broadening of molecular lines. These measurements constrain disk angular momentum transport, and furnish evidence of the turbulent…

Solar and Stellar Astrophysics · Physics 2015-05-28 Jacob B. Simon , Philip J. Armitage , Kris Beckwith

Magnetohydrodynamic (MHD) turbulence plays a critical role in many key astrophysical processes such as star formation, acceleration of cosmic rays, and heat conduction. However, its properties are still poorly understood. We explore how to…

High Energy Astrophysical Phenomena · Physics 2024-10-30 Ru-Yue Wang , Jian-Fu Zhang , Fang Lu , Fu-Yuan Xiang

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

We present results of large-scale three-dimensional simulations of weakly magnetized supersonic turbulence at grid resolutions up to 1024^3 cells. Our numerical experiments are carried out with the Piecewise Parabolic Method on a Local…

Astrophysics of Galaxies · Physics 2009-08-13 Alexei G. Kritsuk , Sergey D. Ustyugov , Michael L. Norman , Paolo Padoan

Two dimensional compressible magneto-hydrodynamical (MHD) simulations run for 20 crossing times on a 800x640 grid with two stable thermal states show persistent hierarchical density structures and Kolmogorov turbulent motions in the…

Astrophysics · Physics 2009-10-31 Bruce G. Elmegreen

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

This study is motivated by recent observations on ubiquitous interstellar density filaments and guided by modern theories of compressible magnetohydrodynamic (MHD) turbulence. The interstellar turbulence shapes the observed density…

Astrophysics of Galaxies · Physics 2019-08-07 Siyao Xu , Suoqing Ji , A. Lazarian

This study shows the connection between three previously observed but seemingly unrelated phenomena in hydrodynamic (HD) and magnetohydrodynamic (MHD) turbulent flows, involving the emergence of fluctuations occurring on very long time…

Fluid Dynamics · Physics 2015-05-28 P. Dmitruk , P. D. Mininni , A. Pouquet , S. Servidio , W. H. Matthaeus

Recent advances in understanding of magnetohydrodynamic (MHD) turbulence call for revisions in the picture of particle acceleration. We make use of the recently established scaling of slow and fast MHD modes in strong and weak MHD…

Astrophysics · Physics 2016-08-30 Jungyeon Cho , A. Lazarian

The dynamics of molecular clouds is characterized by supersonic random motions in the presence of a magnetic field. We study this situation using numerical solutions of the three-dimensional compressible magneto-hydrodynamic (MHD) equations…

Astrophysics · Physics 2009-10-30 Paolo Padoan , Mika Juvela , John Bally , AAke Nordlund

We review recent results from numerical simulations and related models of MHD turbulence in the interstellar medium (ISM) and in molecular clouds. We discuss the implications of turbulence for the processes of cloud formation and evolution,…

Astrophysics · Physics 2007-05-23 E. Vazquez-Semadeni , E. C. Ostriker , T. Passot , C. F. Gammie , J. M. Stone

Linear analysis of the stability of diffuse clouds in the cold neutral medium with uniform magnetic field is performed. We consider that gas in equilibrium state is heated by cosmic rays, X-rays and electronic photoeffect on the surface of…

Solar and Stellar Astrophysics · Physics 2019-05-22 Alexander E. Dudorov , Constantine E. Stepanov , Sergey O. Fomin , Sergey A. Khaibrakhmanov

Supersonic turbulence in molecular clouds is a dominant agent that strongly affects the clouds' evolution and star formation activity. Turbulence may be initiated and maintained by a number of processes, acting at a wide range of physical…

Astrophysics of Galaxies · Physics 2014-11-20 C. M. Brunt , M. H. Heyer , M. -M. Mac Low

We extend previous studies of the physics of interstellar cloud collisions by beginning investigation of the role of magnetic fields through 2D magnetohydrodynamic (MHD) numerical simulations. We study head-on collisions between equal mass,…

Astrophysics · Physics 2009-10-30 Francesco Miniati , Dongsu Ryu , Andrea Ferrara , T. W. Jones

As a fundamental astrophysical process, the scattering of particles by turbulent magnetic fields has its physical foundation laid by the magnetohydrodynamic (MHD) turbulence theory. In the framework of the modern theory of MHD turbulence,…

High Energy Astrophysical Phenomena · Physics 2018-11-28 Siyao Xu , Alex Lazarian

We numerically investigate the driving of MHD turbulence by gravitational contraction using simulations of an initially spherical, magnetically supercritical cloud core with initially transonic and trans-Alfv\'enic turbulence. We perform a…

Astrophysics of Galaxies · Physics 2024-03-04 Enrique Vázquez-Semadeni , Yue Hu , Siyao Xu , Rubén Guerrero-Gamboa , Alex Lazarian

It is well established now that the solar atmosphere, from photosphere to the corona and the solar wind is a highly structured medium. Satellite observations have confirmed the presence of steady flows. Here, we investigate the parallel…

Solar and Stellar Astrophysics · Physics 2015-05-13 I. Zhelyazkov

Turbulent diffuse molecular clouds can exhibit complicated morphologies caused by the interactions among radiation, chemistry, fluids, and fields. We performed full 3D simulations for turbulent diffuse molecular interstellar media,…

Astrophysics of Galaxies · Physics 2024-07-17 Nannan Yue , Lile Wang , Thomas Bisbas , Donghui Quan , Di Li

We analyze 3D numerical simulations of driven incompressible magnetohydrodynamic (MHD) turbulence in a periodic box threaded by a moderately strong external magnetic field. We sum over nonlinear interactions within Fourier wavebands and…

Astrophysics · Physics 2011-05-10 Jungyeon Cho , Alex Lazarian , Ethan Vishniac