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Related papers: Limits on Magnetic Field Amplification from the r-…

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Instabilities in magnetic fields wound up by differential rotation as reviewed in Spruit (1999) are discussed with some detail and new developments added. In stellar models which include magnetic torques, the differential rotation tends to…

Astrophysics · Physics 2007-05-23 H. C. Spruit

The characteristic physical properties of rotating neutron stars under the r-mode oscillation are evaluated using the finite-range simple effective interaction. Emphasis is given on examining the influence of the stiffness of both the…

Nuclear Theory · Physics 2018-05-09 S. P. Pattnaik , T. R. Routray , X. Viñas , D. N. Basu , M. Centelles , K. Madhuri , B. Behera

The growth rate of the non-linear ablative Rayleigh-Taylor (RT) instability is enhanced by magnetic fields self-generated by the Biermann battery mechanism; a scaling for this effect with perturbation height and wavelength is proposed and…

Plasma Physics · Physics 2023-02-08 C. A. Walsh , D. S. Clark

Stars are, generically, rotating and magnetised objects with a misalignment between their magnetic and rotation axes. Since a magnetic field induces a permanent distortion to its host, it provides effective rigidity even to a fluid star,…

Solar and Stellar Astrophysics · Physics 2017-03-23 S. K. Lander , D. I. Jones

We study the stability of neutron stars with toroidal magnetic fields by magnetohydrodynamic simulation in full general relativity under assumption of axial symmetry. Nonrotating and rigidly rotating neutron stars are prepared for a variety…

Astrophysics · Physics 2008-12-18 Kenta Kiuchi , Masaru Shibata , Shijun Yoshida

Stability properties of magnetic-field configurations containing the toroidal and axial field are considered. The stability is treated by making use of linear analysis. It is shown that the conditions required for the onset of instability…

Astrophysics · Physics 2009-11-13 Alfio Bonanno , Vadim Urpin

The magnetic field in stellar radiation zones can play an important role in phenomena such as mixing, angular momentum transport, etc. We study the effect of rotation on the stability of a predominantly toroidal magnetic field in the…

Solar and Stellar Astrophysics · Physics 2015-06-15 Alfio Bonanno , Vadim Urpin

During the first 40 s after their birth, proto-neutron stars are expected to be subject to at least two types of instability: the convective instability and the neutron-finger one. Both instabilities involve convective motions and hence can…

Astrophysics · Physics 2009-06-23 L. Naso , L. Rezzolla , A. Bonanno , L. Paternò

In this review we summarize the current understanding of the gravitational-wave driven instability associated with the so-called r-modes in rotating neutron stars. We discuss the nature of the r-modes, the detailed mechanics of the…

General Relativity and Quantum Cosmology · Physics 2014-11-17 N. Andersson , K. D. Kokkotas

If a magnetic field normal to the surface of a magnetic fluid is increased beyond a critical value a spontaneous deformation of the surface arises (normal field instability). The instability is subcritical and leads to peaks of a…

patt-sol · Physics 2016-09-08 Thomas Mahr , Ingo Rehberg

We present three-dimensional simulations of the dynamical bar-mode instability in magnetized and differentially rotating stars in full general relativity. Our focus is on the effects that magnetic fields have on the dynamics and the onset…

General Relativity and Quantum Cosmology · Physics 2015-06-16 Luca Franci , Roberto De Pietri , Kyriaki Dionysopoulou , Luciano Rezzolla

The loss of angular momentum due to unstable r-modes in hot young neutron stars has been proposed as a mechanism for achieving the spin rates inferred for young pulsars. One factor that could have a significant effect on the action of the…

Astrophysics · Physics 2009-11-07 Anna. L. Watts , Nils. Andersson

We study the amplification of magnetic fields in the collapse and the post-bounce evolution of the core of a non-rotating star of 15 solar masses in axisymmetry. To this end, we solve the coupled equations of magnetohydrodynamics and…

Solar and Stellar Astrophysics · Physics 2015-06-19 Martin Obergaulinger , Thomas Janka , Miguel Ángel Aloy Torás

There exists both theoretical and observational evidence that the magnetic field decay in neutron stars may proceed in a pronounced non--linear way during a certain episode of the neutron star's life. In the presence of a strong magnetic…

Astrophysics · Physics 2009-11-07 U. Geppert , M. Rheinhardt

We study a resistive tearing instability developing in a system evolving through the combined effect of Hall drift in the Electron-MHD limit and Ohmic dissipation. We explore first the exponential growth of the instability in the linear…

High Energy Astrophysical Phenomena · Physics 2016-09-19 Konstantinos N. Gourgouliatos , Rainer Hollerbach

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

We use a luminous fast magnetic rotator model to analyze the influence of a magnetic field on the linear waves induced in the wind of a massive star by the radiative instability. We show that a twisted magnetic field can drive a strong wind…

Astrophysics · Physics 2007-05-23 Henning Seemann , Peter L. Biermann

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

Cosmic-ray streaming instabilities at supernova shocks are discussed in the quasilinear diffusion formalism which takes into account the feedback effect of wave growth on the cosmic ray streaming motion. In particular, the nonresonant…

High Energy Astrophysical Phenomena · Physics 2015-05-13 Qinghuan Luo , Don Melrose

The MHD instabilities can generate complex field topologies even if the initial field configuration is a very simple one. We consider the stability properties of magnetic configurations containing a toroidal and an axial field. In this…

Astrophysics · Physics 2009-11-13 Alfio Bonanno , Vadim Urpin