English
Related papers

Related papers: Sub-Alfvenic Non-Ideal MHD Turbulence Simulations …

200 papers

Most numerical investigations on the role of magnetic fields in turbulent molecular clouds (MCs) are based on ideal magneto-hydrodynamics (MHD). However, MCs are weakly ionized, so that the time scale required for the magnetic field to…

Astrophysics · Physics 2009-11-13 Pak Shing Li , Christopher F. McKee , Richard I. Klein , Robert T. Fisher

We study the role of ambipolar diffusion (AD) on the non-linear evolution of the MRI in protoplanetary disks using the strong coupling limit, which applies when the electron recombination time is much shorter than the orbital time. The…

Earth and Planetary Astrophysics · Physics 2015-05-27 Xue-Ning Bai , James M. Stone

Though flux freezing is a good approximation frequently assumed for molecular clouds, ambipolar diffusion (AD) is inevitable at certain scales. The scale at which AD sets in can be a crucial parameter for turbulence and the star formation…

Solar and Stellar Astrophysics · Physics 2015-05-18 Hua-bai Li , Martin Houde , Shih-ping Lai , T. K. Sridharan

The dissipation of kinetic and magnetic energy in the interstellar medium (ISM) can proceed through viscous, Ohmic or ambipolar diffusion (AD). It occurs at very small scales compared to the scales at which energy is presumed to be…

Astrophysics of Galaxies · Physics 2015-02-13 Georgios Momferratos , Pierre Lesaffre , Edith Falgarone , Guillaume Pineau des Forêts

The temperature of the gas in molecular clouds is a key determinant of the characteristic mass of star formation. Ambipolar diffusion (AD) is considered one of the most important heating mechanisms in weakly ionized molecular clouds. In…

Solar and Stellar Astrophysics · Physics 2015-06-11 Pak Shing Li , Andrew Myers , Christopher F. McKee

We study the effects of ambipolar diffusion (AD) on hydromagnetic turbulence. In most of the cases, we use the single fluid approximation where the drift velocity between charged and neutral particles is proportional to the Lorentz force.…

Astrophysics of Galaxies · Physics 2019-06-13 Axel Brandenburg

Under ideal MHD conditions the magnetic field strength should be correlated with density in the interstellar medium (ISM). However, observations indicate that this correlation is weak. Ambipolar diffusion can decrease the flux-to-mass ratio…

Astrophysics · Physics 2009-11-10 F. Heitsch , E. G. Zweibel , A. D. Slyz , J. E. G. Devriendt

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

In the present-day universe, magnetic fields play such essential roles in star formation as angular momentum transport and outflow driving, which control circumstellar disc formation/fragmentation and also the star formation efficiency.…

Astrophysics of Galaxies · Physics 2022-12-28 Kenji Eric Sadanari , Kazuyuki Omukai , Kazuyuki Sugimura , Tomoaki Matsumoto , Kengo Tomida

We use local numerical simulations to investigate the strength and nature of magnetohydrodynamic (MHD) turbulence in the outer regions of protoplanetary disks, where ambipolar diffusion is the dominant non-ideal MHD effect. The simulations…

Solar and Stellar Astrophysics · Physics 2015-06-11 Jacob B. Simon , Xue-Ning Bai , James M. Stone , Philip J. Armitage , Kris Beckwith

Ambipolar diffusion is important in redistributing magnetic flux and in damping Alfven waves in molecular clouds. The importance of ambipolar diffusion on a length scale $\ell$ is governed by the ambipolar diffusion Reynolds number,…

Solar and Stellar Astrophysics · Physics 2015-05-19 Christopher F. McKee , Pak Shing Li , Richard I. Klein

Owing to the complexity of turbulent magnetic fields, modeling the diffusion of cosmic rays is challenging. Based on the current understanding of anisotropic magnetohydrodynamic (MHD) turbulence, we use test particles to examine the cosmic…

Astrophysics of Galaxies · Physics 2022-02-16 Yue Hu , A. Lazarian , Siyao Xu

It is well known that non-ideal magnetohydrodynamic effects are important in the dynamics of molecular clouds: both ambipolar diffusion and possibly the Hall effect have been identified as significant. We present the results of a suite of…

Astrophysics of Galaxies · Physics 2014-11-20 T. P. Downes , S. O'Sullivan

It is generally believed that turbulence has a significant impact on the dynamics and evolution of molecular clouds and the star formation which occurs within them. Non-ideal magnetohydrodynamic effects are known to influence the nature of…

Astrophysics of Galaxies · Physics 2015-03-17 Turlough P. Downes , Stephen O'Sullivan

Disks are essential to the formation of both stars and planets, but how they form in magnetized molecular cloud cores remains debated. This work focuses on how the disk formation is affected by turbulence and ambipolar diffusion (AD), both…

Solar and Stellar Astrophysics · Physics 2019-09-02 Ka Ho Lam , Zhi-Yun Li , Che-Yu Chen , Kengo Tomida , Bo Zhao

We investigate the nature of the Alfv\'enic turbulence cascade in two fluid MHD simulations in order to determine if turbulence is damped once the ion and neutral species become decoupled at a critical scale called the ambipolar diffusion…

Astrophysics of Galaxies · Physics 2015-06-03 Blakesley Burkhart , A. Lazarian , D. Balsara , C. Meyer , J. Cho

We present results from two-dimensional numerical simulations of a supersonic turbulent flow in the plane of the galactic disk, incorporating shear, thresholded and discrete star formation (SF), self-gravity, rotation and magnetic fields. A…

Astrophysics · Physics 2009-10-28 T. Passot , E. Vazquez-Semadeni , A. Pouquet

Turbulence is a complex physical process prevalent in modern physics, particularly in ionized environments like interstellar gas, where magnetic fields play a dynamic role. However, the precise influence of magnetic fields in such settings…

Astrophysics of Galaxies · Physics 2025-08-12 Guang-Xing Li , Mengke Zhao

Supersonic turbulence is a large reservoir of suprathermal energy in the interstellar medium. Its dissipation, because it is intermittent in space and time, can deeply modify the chemistry of the gas. We further explore a hybrid method to…

Astrophysics of Galaxies · Physics 2009-11-13 Benjamin Godard , Edith Falgarone , Guillaume Pineau Des Forêts

We have implemented non-ideal Magneto-Hydrodynamics (MHD) effects in the Adaptive Mesh Refinement (AMR) code RAMSES, namely ambipolar diffusion and Ohmic dissipation, as additional source terms in the ideal MHD equations. We describe in…

Solar and Stellar Astrophysics · Physics 2015-10-22 J. Masson , R. Teyssier , C. Mulet-Marquis , P. Hennebelle , G. Chabrier
‹ Prev 1 2 3 10 Next ›