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Related papers: MHD instabilities in accretion mounds - II. 3D sim…

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This paper reports on 3D numerical simulations of dynamics and thermodynamics in the diffuse ISM. Our models are local, account for sheared galactic rotation, magnetic fields, and realistic cooling, and resolve scales ~1-200 pc. This…

Astrophysics · Physics 2009-11-11 Robert A. Piontek , Eve C. Ostriker

Magnetic fields have been observed in massive Ap/Bp stars and presumably are also present in the radiative zone of solar-like stars. Yet, to date there is no clear understanding of the dynamics of the magnetic field in stably stratified…

Solar and Stellar Astrophysics · Physics 2023-03-27 G. Monteiro , G. Guerrero , F. Del Sordo , A. Bonanno , P. K. Smolarkiewicz

(Abridged) Numerical magnetohydrodynamic (MHD) simulations of a turbulent solar nebula are used to study the growth of dust mantles swept up by chondrules. A small neighborhood of the solar nebula is represented by an orbiting patch of gas…

Earth and Planetary Astrophysics · Physics 2010-12-03 Augusto Carballido

Discretized numerical simulations are a powerful tool for investigation of nonlinear MHD turbulence in accretion disks. However, confidence in their quantitative predictions requires a demonstration that further refinement of the spatial…

High Energy Astrophysical Phenomena · Physics 2015-05-27 John F. Hawley , Xiaoyue Guan , Julian H. Krolik

It has been recently argued through numerical work that rotating stars with a high degree of differential rotation are dynamically unstable against bar-mode deformation, even for values of the ratio of rotational kinetic energy to…

Astrophysics · Physics 2009-06-23 Pablo Cerdá-Durán , Vicent Quilis , José A. Font

We present 3D MHD simulations of purely toroidal and mixed poloidal-toroidal magnetic field configurations to study the behavior of the Tayler instability. For the first time the simultaneous action of rotation and magnetic diffusion are…

Solar and Stellar Astrophysics · Physics 2015-05-27 Juan C. Ibañez-Mejia , Jonathan Braithwaite

A wide variety of astrophysical phenomena involve the flow of turbulent magnetized gas with relativistic velocity or energy density. Examples include gamma-ray bursts, active galactic nuclei, pulsars, magnetars, micro-quasars, merging…

High Energy Astrophysical Phenomena · Physics 2015-05-30 Jonathan Zrake , Andrew MacFadyen

This paper presents a series of global three dimensional accretion disk simulations carried out in the cylindrical limit in which the vertical component of the gravitational field is neglected. The simulations use a cylindrical…

Astrophysics · Physics 2009-10-31 John F. Hawley

We report long-term simulations of black hole-neutron star binary mergers where the neutron star possesses an asymmetric magnetic field dipole. Focusing on the scenario where the neutron star is tidally disrupted by the black hole, we track…

High Energy Astrophysical Phenomena · Physics 2017-05-12 Mew-Bing Wan

The evolution of the r-mode instability is likely to be accompanied by secular kinematic effects which will produce differential rotation with large scale drifts of fluid elements, mostly in the azimuthal direction. As first discussed by…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Luciano Rezzolla , Frederick L. Lamb , Dragoljub Markovic , Stuart L. Shapiro

The transport of cosmic rays (CRs) is crucial for the understanding of almost all high-energy phenomena. Both pre-existing large-scale magnetohydrodynamic (MHD) turbulence and locally generated turbulence through plasma instabilities are…

High Energy Astrophysical Phenomena · Physics 2018-02-28 Olga Lebiga , Reinaldo Santos-Lima , Huirong Yan

We carried out three-dimensional global resistive magnetohydrodynamic (MHD) simulations of the cooling instability in optically thin hot black hole accretion flows by assuming bremsstrahlung cooling. General relativistic effects are…

Astrophysics · Physics 2015-06-24 Mami Machida , Kenji Nakamura , Ryoji Matsumoto

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

The magnetorotational instability (MRI) can be a powerful mechanism amplifying the magnetic field in core-collapse supernovae. Whether initially weak magnetic fields can be amplified by this instability to dynamically relevant strengths is…

Solar and Stellar Astrophysics · Physics 2016-03-03 Tomasz Rembiasz , Martin Obergaulinger , Pablo Cerdá-Durán , Ewald Müller , Miguel-Ángel Aloy

We study the influence of the choice of transport coefficients (viscosity and resistivity) on MHD turbulence driven by the magnetorotational instability (MRI) in accretion disks. We follow the methodology described in paper I: we adopt an…

Astrophysics · Physics 2009-11-13 S. Fromang , J. Papaloizou , G. Lesur , T. Heinemann

Unveiling the evolution of toroidal field instability, known as Tayler instability, is essential to understand the strength and topology of the magnetic fields observed in early-type stars, in the core of the red giants, or in any stellar…

Solar and Stellar Astrophysics · Physics 2019-10-23 G. Guerrero , F. Del Sordo , A. Bonanno , P. K. Smolarkiewicz

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

In order to understand the origin of observed molecular cloud properties, it is critical to understand how clouds interact with their environments during their formation, growth, and collapse. It has been suggested that accretion-driven…

Astrophysics of Galaxies · Physics 2018-12-21 Juan C. Ibáñez-Mejía , Mordecai-Mark Mac Low , Ralf S. Klessen , Christian Baczynski

It is well-known that the cores of massive stars sustain a stellar dynamo with a complex magnetic field configuration. However, the same cannot be said for the field's strength and geometry at the convective-radiative boundary, which are…

Solar and Stellar Astrophysics · Physics 2024-12-16 Rathish P. Ratnasingam , Philipp V. F. Edelmann , Dominic M. Bowman , Tamara M. Rogers

Using general-relativistic hydrodynamical simulations, we show that merging binary neutron stars can form hypermassive neutrons stars that undergo the one-arm spiral instability. We study the particular case of a dynamical capture merger…

High Energy Astrophysical Phenomena · Physics 2016-01-06 Vasileios Paschalidis , William E. East , Frans Pretorius , Stuart L. Shapiro