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Related papers: Localized magnetorotational instability and its ro…

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The magnetorotational instability (MRI) occurs when a weak magnetic field destabilises a rotating, electrically conducting fluid with inwardly increasing angular velocity. The MRI is essential to astrophysical disk theory where the shear is…

We show that an MHD-instability driven dynamo (IDD) operating in a hot accretion disk is capable of generating energetically adequate magnetic flux deposition rates above and below a mildly advective accretion disk structure. The dynamo is…

Astrophysics · Physics 2009-10-31 Rafael Angel Araya-Gochez

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

Magnetorotational instability (MRI)-driven turbulence and dynamo phenomena are analyzed using direct statistical simulations. Our approach begins by developing a unified mean-field model that combines the traditionally decoupled problems of…

High Energy Astrophysical Phenomena · Physics 2025-05-07 Tushar Mondal , Pallavi Bhat

We investigate the significance of large scale azimuthal, magnetic and velocity modes for the MRI turbulence in accretion disks. We perform 3D global ideal MHD simulations of global stratified proto-planetary disk models. Our domains span…

Solar and Stellar Astrophysics · Physics 2015-05-30 M. Flock , N. Dzyurkevich , H. Klahr , N. Turner , Th. Henning

The magneto-rotational instability (MRI) is considered to be a promising mechanism to amplify the magnetic field in fast rotating protoneutron stars. In contrast to accretion disks, radial buoyancy driven by entropy and lepton fraction…

High Energy Astrophysical Phenomena · Physics 2015-06-23 Jerome Guilet , Ewald Mueller

It is widely believed that in active galactic nuclei (AGNs) a supermassive black hole with an accretion disk is surrounded by an optically and geometrically thick torus at sub-parsec scale. However, it is not clear how is the mass supply…

Astrophysics of Galaxies · Physics 2018-12-24 Yuki Kudoh , Keiichi Wada

Magneto-rotational instability (MRI) and gravitational instability (GI) are the two principle routes to turbulent angular momentum transport in accretion disks. Protoplanetary disks may develop both. This paper aims to reinvigorate interest…

Earth and Planetary Astrophysics · Physics 2015-06-19 Min-Kai Lin

Magnetorotational Instability (MRI), the instability causing turbulent transport in accretion disks, is studied in the kinetic regime. Radiatively Inefficient Accretion Flows (RIAFs), like the one around the supermassive black hole in the…

Astrophysics · Physics 2007-05-23 Prateek Sharma

For over 30 years, the Magneto-Rotational Instability has been accepted as the mechanism driving accretion disk turbulence. Its physical basis is well understood, where an interplay between centrifugal forces and magnetic tension transfers…

Astrophysics of Galaxies · Physics 2025-07-31 Nicolas Brughmans , Rony Keppens

The standard magnetorotational instability (SMRI) is a promising mechanism for turbulence and rapid accretion in astrophysical disks. It is a magnetohydrodynamic (MHD) instability that destabilizes otherwise hydrodynamically stable disk…

The magnetorotational instability (MRI) is believed to be responsible for most of the angular momentum transport in accretion discs. However, molecular dissipation processes may drastically change the efficiency of MRI turbulence in…

Earth and Planetary Astrophysics · Physics 2015-05-20 Geoffroy Lesur , Pierre-Yves Longaretti

Turbulent motion driven by the magnetorotational instability (MRI) is believed to provide an anomalous viscosity strong enough to account for observed accretion rates in protostellar accretion disks. In the first of two papers, we perform…

Solar and Stellar Astrophysics · Physics 2015-06-19 Wayne O'Keeffe , Turlough P. Downes

The linear instability of thin, vertically-isothermal Keplerian discs, under the influence of axial magnetic field is investigated. Solutions of the stability problem are found explicitly by asymptotic expansions in the small aspect ratio…

Solar and Stellar Astrophysics · Physics 2015-06-03 E. Liverts , Yu. Shtemler , M. Mond

The magnetorotational instability (MRI) is considered a leading mechanism for driving angular momentum transport in differentially rotating astrophysical flows, including accretion disks and protoneutron stars. This process is mediated by…

High Energy Astrophysical Phenomena · Physics 2025-04-02 Miquel Miravet-Tenés , Martin E. Pessah

The origin of large-scale and coherent magnetic fields in astrophysical discs is an important and long standing problem. Researchers commonly appeal to a turbulent dynamo, sustained by the magneto-rotational instability (MRI), to supply the…

High Energy Astrophysical Phenomena · Physics 2018-10-24 A. Riols , H. Latter

In this paper we investigate the influence of radiative transport on the growth of the magnetorotational instability (MRI) in accretion discs. The analysis is performed by use of analytical and numerical means. We provide a general…

Solar and Stellar Astrophysics · Physics 2015-05-13 M. Flaig , R. Kissmann , W. Kley

We examine the properties of strongly magnetized accretion discs in a global framework, with particular focus on the evolution of magnetohydrodynamic instabilities such as the magnetorotational instability (MRI). Work by Pessah and Psaltis…

High Energy Astrophysical Phenomena · Physics 2017-11-13 Upasana Das , Mitchell C. Begelman , Geoffroy Lesur

The saturation level of the magnetorotational instability (MRI) is investigated using three-dimensional MHD simulations. The shearing box approximation is adopted and the vertical component of gravity is ignored, so that the evolution of…

Astrophysics · Physics 2009-11-10 Takayoshi Sano , Shu-ichiro Inutsuka , Neal J. Turner , James M. Stone

The magnetorotational instability (MRI) is a fundamental process of accretion disk physics, but its saturation mechanism remains poorly understood despite considerable theoretical and computational effort. We present a multiple scales…

High Energy Astrophysical Phenomena · Physics 2017-05-24 S. E. Clark , Jeffrey S. Oishi