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

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We have performed stability analysis of axisymmetric accretion mounds on neutron stars in High Mass X-ray Binaries (HMXB) by 2-D MHD simulations with the PLUTO MHD code. We find that the mounds are stable with respect to interchange…

High Energy Astrophysical Phenomena · Physics 2013-03-04 Dipanjan Mukherjee , Dipankar Bhattacharya , Andrea Mignone

We have numerically solved the Grad-Shafranov equation for axisymmetric static MHD equilibria of matter confined at the polar cap of neutron stars. From the equilibrium solutions we explore the stability of the accretion mounds using the…

High Energy Astrophysical Phenomena · Physics 2013-05-14 Dipanjan Mukherjee , Dipankar Bhattacharya , Andrea Mignone

In accreting neutron star binaries, matter is channelled by the magnetic fields from the accretion disc to the poles of neutron stars forming an accretion mound. We model such mounds by numerically solving the Grad-Shafranov equation for…

High Energy Astrophysical Phenomena · Physics 2015-06-17 Dipanjan Mukherjee , Dipankar Bhattacharya , Andrea Mignone

We examine the hydromagnetic stability of magnetically confined mountains, which arise when material accumulates at the magnetic poles of an accreting neutron star. We extend a previous axisymmetric stability analysis by performing…

Astrophysics · Physics 2009-11-13 M. Vigelius , A. Melatos

Neutron stars harbour extremely strong magnetic fields within their solid outer crust. The topology of this field strongly influences the surface temperature distribution, and hence the star's observational properties. In this work, we…

High Energy Astrophysical Phenomena · Physics 2020-11-04 Davide De Grandis , Roberto Turolla , Toby S. Wood , Silvia Zane , Roberto Taverna , Konstantinos N. Gourgouliatos

We present global 3D MHD simulations of disks of gas and solids, aiming at developing models that can be used to study various scenarios of planet formation and planet-disk interaction in turbulent accretion disks. A second goal is to show…

Astrophysics · Physics 2009-11-13 W. Lyra , A. Johansen , H. Klahr , N. Piskunov

We present three-dimensional MHD simulations of rotating radiatively inefficient accretion flows onto black holes. In the simulations, we continuously inject magnetized matter into the computational domain near the outer boundary, and we…

Astrophysics · Physics 2009-11-07 Igor V. Igumenshchev , Ramesh Narayan , Marek A. Abramowicz

A new type of instability that is expected to drive magnetohydrodynamic (MHD) turbulence from a purely toroidal magnetic field in an accretion disk is presented. It is already known that in a differentially rotating system, the uniform…

High Energy Astrophysical Phenomena · Physics 2016-05-25 Kota Hirabayashi , Masahiro Hoshino

We discuss results of global 3D MHD simulations of accretion on to a rotating magnetized star with a tilted dipole magnetic field, where the accretion is driven by the magneto-rotational instability (MRI). The simulations show that…

Solar and Stellar Astrophysics · Physics 2015-06-03 M. M. Romanova , G. V. Ustyugova , A. V. Koldoba , R. V. E. Lovelace

We report on the first global three-dimensional (3D) MHD simulations of disk accretion onto a rotating magnetized star through the Rayleigh-Taylor instability. The star has a dipole field misaligned relative to the rotation axis by a small…

Astrophysics · Physics 2018-01-17 Marina M. Romanova , Akshay K. Kulkarni , Richard V. E. Lovelace

Relativistic magnetized jets, such as those from AGN, GRBs and XRBs, are susceptible to current- and pressure-driven MHD instabilities that can lead to particle acceleration and non-thermal radiation. Here we investigate the development of…

We present results of 3D simulations of MHD instabilities at the accretion disk-magnetosphere boundary. The instability is Rayleigh-Taylor, and develops for a fairly broad range of accretion rates and stellar rotation rates and magnetic…

Astrophysics · Physics 2008-03-09 Akshay K. Kulkarni , Marina M. Romanova

3D Magnetohydrodynamic simulations show that when matter accretes onto neutron stars, in particular if the misalignment angle is small, it does not constantly fall at a fixed spot. Instead, the location at which matter reaches the star…

High Energy Astrophysical Phenomena · Physics 2015-05-14 Matteo Bachetti , Marina Romanova , Akshay Kulkarni , Luciano Burderi , Tiziana di Salvo , .

We report on the second phase of our study of slightly rotating accretion flows onto black holes. We consider magnetohydrodynamical (MHD) accretion flows with a spherically symmetric density distribution at the outer boundary, but with…

Astrophysics · Physics 2009-11-07 D. Proga , M. C. Begelman

We present full 2 Pi global 3-D stratified MHD simulations of accretion disks. We interpret our results in the context of proto-planetary disks. We investigate the turbulence driven by the magneto-rotational instability (MRI) using the…

Earth and Planetary Astrophysics · Physics 2015-05-27 M. Flock , N. Dzyurkevich , H. Klahr , N. J. Turner , Th. Henning

We present results of 3D simulations of MHD instabilities at the accretion disk-magnetosphere boundary. The instability is Rayleigh-Taylor, and develops for a fairly broad range of accretion rates and stellar rotation rates and magnetic…

Astrophysics · Physics 2009-11-13 Akshay K. Kulkarni , Marina M. Romanova

We present three-dimensional (3-D) magnetohydrodynamical (MHD) simulations of radiatively inefficient accretion flow around black holes. General relativistic effects are simulated by using the pseudo-Newtonian potential. We start…

Astrophysics · Physics 2009-11-10 Yoshiaki Kato , Shin Mineshige , Kazunari Shibata

Three-dimensional numerical magnetohydrodynamic (MHD) simulations are performed to investigate how a magnetically confined mountain on an accreting neutron star relaxes resistively. No evidence is found for non-ideal MHD instabilities on a…

High Energy Astrophysical Phenomena · Physics 2009-11-13 M. Vigelius , A. Melatos

The aim of this paper is to study the vertical profile of small dust particles in protoplanetary discs in which angular momentum transport is due to MHD turbulence driven by the magnetorotational instability. We consider particle sizes that…

Earth and Planetary Astrophysics · Physics 2009-11-13 Sebastien Fromang , Richard P. Nelson

We present analytical and numerical studies of magnetorotational instabilities occuring in magnetized accretion disks. In these studies we make use of the linearised compressible MHD equations. These calculations are performed for general…

Astrophysics · Physics 2011-07-08 J. W. S. Blokland , E. van der Swaluw , R. Keppens , J. P. Goedbloed
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