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The magneto-rotational instability is presently the most promising source of turbulent transport in accretion disks. However, some important issues still need to be addressed to quantify the role of MRI in disks; in particular no systematic…

Astrophysics · Physics 2009-06-23 G. Lesur , P-Y. Longaretti

We present a linear analysis of the stability of accretion disks in which angular momentum is removed by the magnetic torque exerted by a centrifugally driven wind. The effects of the dependence of the wind torque on field strength and…

Astrophysics · Physics 2009-11-07 Xinwu Cao , H. C. Spruit

The magnetorotational instability (MRI) drives vigorous turbulence in a region of protoplanetary disks where the ionization fraction is sufficiently high. It has recently been shown that the electric field induced by the MRI can heat up…

Earth and Planetary Astrophysics · Physics 2016-02-03 Shoji Mori , Satoshi Okuzumi

We investigate the stability of differentially rotating proto-neutron stars (PNSs) with a toroidal magnetic field. Stability criteria for nonaxisymmetric MHD instabilities are derived using a local linear analysis. PNSs are expected to have…

Astrophysics · Physics 2009-11-13 Youhei Masada , Takayoshi Sano , Hideaki Takabe

This paper is the first in a series investigating magnetohydrodynamic instabilities that may contribute to angular-momentum transport and magnetic-field evolution in stellar radiative zones. We focus on shear-driven instabilities,…

Solar and Stellar Astrophysics · Physics 2026-02-10 V. Durepaire , L. Petitdemange , K. Belkacem , A. Guseva , L. Manchon , R. Hollerbach , F. Daniel

Magnetorotational instability (MRI) in a convectively-stable layer around the neutrinosphere is simulated by a three-dimensional model of supernova core. To resolve MRI-unstable modes, a thin layer approximation considering only the radial…

High Energy Astrophysical Phenomena · Physics 2015-06-23 Youhei Masada , Tomoya Takiwaki , Kei Kotake

We investigate the migration of low-mass planets ($5 M_{\oplus}$ and $20 M_{\oplus}$) in accretion discs threaded with a magnetic field using 2D MHD code in polar coordinates. We observed that, in the case of a strong azimuthal magnetic…

Earth and Planetary Astrophysics · Physics 2016-04-27 M. L. Comins , M. M. Romanova , A. V. Koldoba , G. V. Ustyugova , R. V. E. Lovelace

We examine the MHD instabilities arising in the radiation zone of a differentially rotating star, in which a poloidal field of fossil origin is sheared into a toroidal field. We focus on the non-axisymmetric instability that affects the…

Astrophysics · Physics 2009-11-13 J. -P. Zahn , A. S. Brun , S. Mathis

Magnetorotational instability (MRI) is the most promising mechanism behind accretion in low-mass protostellar disks. Here we present the first analysis of the global structure and evolution of non-ideal MRI-driven T-Tauri disks on…

Earth and Planetary Astrophysics · Physics 2015-06-15 Russell Landry , Sarah E. Dodson-Robinson , Neal J. Turner , Greg Abram

We investigate shear and buoyancy instabilities in radially stratified, magnetized, cylindrical flows, for application to magnetocentrifugally driven winds and to magnetized accretion disks. We identify and study nine principal types of…

Astrophysics · Physics 2009-10-31 Woong-Tae Kim , Eve C. Ostriker

The Rossby wave instability (RWI), which depends on the density bumps and extremum in the vortensities in the differentially rotating discs, plays an important role in the evolution of the protoplanetary discs. In this article, we…

Earth and Planetary Astrophysics · Physics 2015-06-19 Mahmoud Gholipour , Mohsen Nejad-Asghar

In weakly magnetized, dilute plasmas in which thermal conduction along magnetic field lines is important, the usual convective stability criterion is modified. Instead of depending on entropy gradients, instability occurs for small…

Astrophysics · Physics 2009-11-13 Ian J. Parrish , James M. Stone

Turbulence and dynamo induced by the magnetorotational instability (MRI) are analyzed using quasi-linear statistical simulation methods. It is found that homogenous turbulence is unstable to a large scale dynamo instability, which saturates…

High Energy Astrophysical Phenomena · Physics 2015-06-01 Jonathan Squire , Amitava Bhattacharjee

Magnetic fields in accretion disks play a dominant role during the star formation process but have hitherto been observationally poorly constrained. Field strengths have been inferred on T Tauri stars themselves and possibly in the…

We perform a local stability analysis of rotational flows in the presence of a constant vertical magnetic field and an azimuthal magnetic field with a general radial dependence. Employing the short-wavelength approximation we develop a…

Fluid Dynamics · Physics 2014-11-14 Oleg N. Kirillov , Frank Stefani , Yasuhide Fukumoto

3-D extended-MHD simulations of the magnetized ablative Rayleigh-Taylor instability are presented for the first time. Previous 2-D simulations claiming perturbation suppression by magnetic tension are shown to be misleading, as they do not…

Plasma Physics · Physics 2022-03-14 Christopher A. Walsh

We consider a Taylor-Dean-type flow of an electrically conducting liquid in an annulus between two infinitely long perfectly conducting cylinders subject to a generally helical magnetic field. The cylinders are electrically connected…

Fluid Dynamics · Physics 2009-07-01 Jānis Priede

The saturation mechanism of Magneto-Rotational Instability (MRI) is examined through analytical quasilinear theory and through nonlinear computation of a single mode in a rotating disk. We find that large-scale magnetic field is generated…

High Energy Astrophysical Phenomena · Physics 2011-02-11 F. Ebrahimi , S. C. Prager , D. D. Schnack

In this paper we make an effort to understand the interaction of turbulence generated by the magnetorotational instability (MRI) with turbulence from other sources, such as supernova explosions (SNe) in galactic disks. First we perform a…

Astrophysics of Galaxies · Physics 2015-05-14 Maarit J. Korpi , Petri J. Käpylä , Miikka S. Väisälä

Despite the importance of the magnetorotational instability (MRI) as a fundamental mechanism for angular momentum transport in magnetized accretion disks, it has yet to be demonstrated in the laboratory. A liquid sodium alpha-omega dynamo…

Astrophysics · Physics 2009-11-07 K. Noguchi , V. I. Pariev , S. A. Colgate , J. Nordhaus , H. F. Beckley
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