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

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We report the results of 3-dimensional magnetohydrodynamic (MHD) simulations of a jet formation by the interaction between an accretion disk and a large scale magnetic field. The disk is not treated as a boundary condition but is solved…

Astrophysics · Physics 2009-11-13 H. Kigure , K. Shibata

It is widely accepted that quasars and other active galactic nuclei (AGN) are powered by accretion of matter onto a central supermassive black hole. While numerical simulations have demonstrated the importance of magnetic fields in…

High Energy Astrophysical Phenomena · Physics 2009-11-13 Peter B. Dobbie , Zdenka Kuncic , Geoffrey V. Bicknell , Raquel Salmeron

We numerically model evolution of magnetic fields inside a neutron star under the influence of ambipolar diffusion in the weak-coupling mode in the one-fluid MHD approximation. Our simulations are three-dimensional and performed in…

High Energy Astrophysical Phenomena · Physics 2022-11-09 Andrei P. Igoshev , Rainer Hollerbach

We have used the AMR hydrodynamic code, MG, to perform idealised 3D MHD simulations of the formation of clumpy and filamentary structure in a thermally unstable medium without turbulence. A stationary thermally unstable spherical diffuse…

Astrophysics of Galaxies · Physics 2016-03-23 C. J. Wareing , J. M. Pittard , S. A. E. G. Falle , S. Van Loo

In former papers we showed that during the decay of a neutron star's magnetic field under the influence of the Hall--drift, an unstable rise of small--scale field structures at the expense of the large--scale background field may happen.…

Astrophysics · Physics 2009-11-10 M. Rheinhardt , D. Konenkov , U. Geppert

Accreting neutron stars are one of the main targets for continuous gravitational wave searches, as asymmetric accretion may lead to quadrupolar deformations, or `mountains', on the crust of the star, which source gravitational wave emission…

High Energy Astrophysical Phenomena · Physics 2020-04-07 Neha Singh , Brynmor Haskell , Dipanjan Mukherjee , Tomasz Bulik

We explore the presence of torques at the inner edges of geometrically-thin black hole accretion disks using 3-dimensional magnetohydrodynamic (MHD) simulations in a pseudo-Newtonian potential. By varying the saturation level of the…

Astrophysics · Physics 2009-11-07 Christopher S. Reynolds , Philip J. Armitage

The aim of this work is to investigate and characterise non-thermal particle behaviour in a three-dimensional (3D) magnetohydrodynamical (MHD) model of unstable multi-threaded flaring coronal loops. We have used a numerical scheme which…

Solar and Stellar Astrophysics · Physics 2018-03-21 J. Threlfall , A. W. Hood , P. K. Browning

Two dimensional compressible magneto-hydrodynamical (MHD) simulations run for 20 crossing times on a 800x640 grid with two stable thermal states show persistent hierarchical density structures and Kolmogorov turbulent motions in the…

Astrophysics · Physics 2009-10-31 Bruce G. Elmegreen

The properties of a new-born neutron star, produced in a core-collapse supernova, can be strongly affected by the possible late fallback which occurs several hours after the explosion. This accretion occurs in the regime dominated by…

High Energy Astrophysical Phenomena · Physics 2010-06-16 Cristian Giovanny Bernal , William H. Lee , Dany Page

The transport of heavy, neutral or charged, point-like particles by incompressible, resistive magnetohydrodynamic (MHD) turbulence is investigated by means of high-resolution numerical simulations. The spatial distribution of such…

Fluid Dynamics · Physics 2015-05-13 H. Homann , J. Bec , H. Fichtner , R. Grauer

We model gas inflow patterns onto circumstellar disks and the evolution of the pseudodisk using three-dimensional resistive MHD simulations. Starting from a prestellar core without turbulence and with a misalignment between the initial…

Solar and Stellar Astrophysics · Physics 2026-02-10 Masahiro N. Machida , Shingo Hirano , Shantanu Basu

The magnetorotational instability (MRI) is considered a key process for driving efficient angular momentum transport in astrophysical disks. Understanding its non-linear saturation constitutes a fundamental problem in modern accretion disk…

High Energy Astrophysical Phenomena · Physics 2012-05-25 Martin E. Pessah

In this paper we present the results of time-dependent simulations of dipolar axisymmetric magnetospheres of neutron stars carried out both within the framework of relativistic magnetohydrodynamics and within the framework of resistive…

Astrophysics · Physics 2009-11-13 S. S. Komissarov

Context. The model of disc fragmentation due to gravitational instabilities offers an alternate formation mechanism for gas giant planets, especially those on wide orbits. Aims. Our goal is to determine the 3D structure of disc-instability…

Earth and Planetary Astrophysics · Physics 2024-02-13 Adam Fenton , Dimitris Stamatellos

Molecular gas disks are generally Toomre stable ($Q_T>$1) and yet clearly gravitationally unstable to structure formation as evidenced by the existence of molecular clouds and ongoing star formation. This paper adopts a 3D perspective to…

Astrophysics of Galaxies · Physics 2022-10-12 Sharon E. Meidt

Prominences show a surprising amount of fine structure and it is widely believed that their threads, as seen in H$\alpha$ observations, provide indirect information concerning magnetic field topology. We investigate the spontaneous…

Solar and Stellar Astrophysics · Physics 2020-04-29 Niels Claes , Rony Keppens , Chun Xia

We study the properties of MHD turbulence driven by the magnetorotational instability (MRI) in accretion disks. We adopt the local shearing box model and focus on the special case for which the initial magnetic flux threading the disk…

Astrophysics · Physics 2009-11-13 S. Fromang , J. Papaloizou

We investigate the stability of the Hall-MHD system and determine its importance for neutron stars at their birth, when they still consist of differentially rotating plasma permeated by extremely strong magnetic fields. We solve the…

Solar and Stellar Astrophysics · Physics 2015-06-04 T. Kondic , G. Ruediger , R. Arlt

Recent high resolution observations unveil ring structures in circumstellar disks. The origin of these rings has been widely investigated under various theoretical scenarios. In this work we perform global 3D non-ideal MHD simulations…

Earth and Planetary Astrophysics · Physics 2019-10-31 Xiao Hu , Zhaohuan Zhu , Satoshi Okuzumi , Xue-Ning Bai , Lile Wang , Kengo Tomida , James M. Stone