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Related papers: MRI: a possible mechanism for funnel flows?

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We re-analyze the physical conditions for Magneto-rotational Instability (MRI) within a steady axisymmetric stratified disk of plasma, in order to account for the so-called isorotation theory (the spatial profile of differential angular…

High Energy Astrophysical Phenomena · Physics 2017-04-26 Francesco Cianfrani , Giovanni Montani

Particle acceleration during the magnetorotational instability (MRI) in a collisionless accretion disk was investigated by using a particle-in-cell (PIC) simulation. We discuss the important role that magnetic reconnection plays not only on…

High Energy Astrophysical Phenomena · Physics 2015-06-16 Masahiro Hoshino

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

The initial magnetic field of previous magnetorotational instability (MRI) simulations has always included a significant system-scale component, even if stochastic. However, it is of conceptual and practical interest to assess whether the…

High Energy Astrophysical Phenomena · Physics 2017-10-13 Pallavi Bhat , Fatima Ebrahimi , Eric G. Blackman , Kandaswamy Subramanian

The magnetorotational instability (MRI) may dominate outward transport of angular momentum in accretion disks, allowing material to fall onto the central object. Previous work has established that the MRI can drive a mean-field dynamo,…

Solar and Stellar Astrophysics · Physics 2015-05-27 Jeffrey S. Oishi , Mordecai-Mark Mac Low

The dynamo driven by the magnetorotational instability (MRI) is believed to play an important role in the dynamics of accretion discs and may also explain the origin of the extreme magnetic fields present in magnetars. Its saturation level…

High Energy Astrophysical Phenomena · Physics 2022-09-21 Jerome Guilet , Alexis Reboul-Salze , Raphael Raynaud , Matteo Bugli , Basile Gallet

Magnetars are highly magnetized neutron stars that can produce X-ray and soft gamma-ray emissions and that have a dipole of $10^{14}$ G to $10^{15}$ G. A promising mechanism for explaining magnetar formation is magnetic field amplification…

High Energy Astrophysical Phenomena · Physics 2022-09-22 Alexis Reboul-Salze , Jérôme Guilet , Raphaël Raynaud , Matteo Bugli

Debris discs are commonly swathed in gas which can be observed in UV, in fine structure lines in FIR, and in resolved maps of CO emission. Carbon and oxygen are overabundant in such gas, but it is severely depleted in hydrogen. As a…

Earth and Planetary Astrophysics · Physics 2016-07-27 Quentin Kral , Henrik Latter

Though usually treated in isolation, the magnetorotational and gravitational instabilities (MRI and GI) may coincide at certain radii and evolutionary stages of protoplanetary discs and active galactic nuclei. Their mutual interactions…

High Energy Astrophysical Phenomena · Physics 2017-12-27 A. Riols , H. Latter

The Magnetorotational Instability (MRI) has long been considered a plausibly ubiquitous mechanism to destabilize otherwise stable Keplerian flows to support radially outward transport of angular momentum. Such an efficient transport process…

Instrumentation and Methods for Astrophysics · Physics 2018-12-13 Derek M. H. Hung , Eric G. Blackman , Kyle J. Caspary , Erik P. Gilson , Hantao Ji

Local simulations of the magnetorotational instability (MRI) in accretion disks can exhibit recurrent coherent structures called channel flows. The formation and destruction of these structures may play a role in the development and…

High Energy Astrophysical Phenomena · Physics 2010-11-02 Henrik N. Latter , Pierre Lesaffre , Steven A. Balbus

Magnetorotational turbulence and magnetically driven disc winds are often considered as separate processes. However, realistic astrophysical discs are expected to be subject to both effects, although possibly at different times and…

High Energy Astrophysical Phenomena · Physics 2015-06-11 Geoffroy Lesur , Jonathan Ferreira , Gordon Ogilvie

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

The possible role of magneto-rotational instability (MRI) and its driven MHD turbulence in the solar interior is studied on the basis of the linear and nonlinear theories coupling with physical parameters, providing solar rotation profile…

Solar and Stellar Astrophysics · Physics 2015-05-20 Youhei Masada

The magnetorotational instability (MRI) is thought to be a powerful source of turbulence and momentum transport in astrophysical accretion discs, but obtaining observational evidence of its operation is challenging. Recently, laboratory…

Fluid Dynamics · Physics 2015-09-15 A. Guseva , A. P. Willis , R. Hollerbach , M. Avila

The magnetorotational (MRI) dynamo has long been considered one of the possible drivers of turbulent angular momentum transport in astrophysical accretion disks. However, various numerical results suggest that this dynamo may be difficult…

High Energy Astrophysical Phenomena · Physics 2015-02-12 A. Riols , F. Rincon , C. Cossu , G. Lesur , G. I. Ogilvie , P-Y. Longaretti

The evolution of warped disks is governed by internal, oscillatory shear flows driven by their distorted geometry. However, these flows are known to be vigorously unstable to a hydrodynamic parametric instability. In many warped systems,…

Solar and Stellar Astrophysics · Physics 2025-08-25 Callum W. Fairbairn , James M. Stone

The azimuthal version of the magnetorotational instability (MRI) is a non-axisymmetric instability of a hydrodynamically stable differentially rotating flow under the influence of a purely or predominantly azimuthal magnetic field. It may…

Numerical calculations and linear theory of radiation magnetohydrodynamic flows indicate that the photon bubble and magnetorotational instability (MRI) may produce large density inhomogeneities in radiation pressure supported media. We…

Astrophysics · Physics 2007-05-23 S. W. Davis , O. M. Blaes , N. J. Turner , A. Socrates

In a hot, dilute, magnetized accretion flow, the electron mean-free path can be much greater than the Larmor radius, thus thermal conduction is anisotropic and along magnetic field lines. In this case, if the temperature decreases outward,…

High Energy Astrophysical Phenomena · Physics 2015-05-20 De-Fu Bu , Feng Yuan , James M Stone