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Related papers: Differential rotation and r-modes in magnetized ne…

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Following the general formalism presented by Rezzolla, Ahmedov and Miller (MNRAS, 322, 723 2001), we here derive analytic solutions of the electromagnetic fields equations in the internal and external background spacetime of a slowly…

General Relativity and Quantum Cosmology · Physics 2007-05-23 L. Rezzolla , B. J. Ahmedov , J. C. Miller

We construct a new three-dimensional general relativistic magnetohydrodynamics code, in which a fixed mesh refinement technique is implemented. To ensure the divergence-free condition as well as the magnetic flux conservation, we employ the…

High Energy Astrophysical Phenomena · Physics 2015-06-05 Kenta Kiuchi , Koutarou Kyutoku , Masaru Shibata

We consider the expulsion of the magnetic field from the super-conducting core of a neutron star and its subsequent decay in the crust. Particular attention is paid to a strong feedback of the distortion of magnetic field lines in the crust…

Astrophysics · Physics 2009-10-31 D. Konenkov , U. Geppert

This paper presents a numerical study over a wide parameter space of the likelihood of the dynamical bar-mode instability in differentially rotating magnetized neutron stars. The innovative aspect of this study is the incorporation of…

Solar and Stellar Astrophysics · Physics 2014-11-20 Karen D. Camarda , Peter Anninos , P. Chris Fragile , José A. Font

We perform the first study of the oscillation frequencies of rapidly rotating neutron stars in alternative theories of gravity, focusing mainly on the fundamental $f$-modes. We concentrated on a particular class of alternative theories -…

General Relativity and Quantum Cosmology · Physics 2017-09-13 Stoytcho S. Yazadjiev , Daniela D. Doneva , Kostas D. Kokkotas

The presence of a viscous boundary layer under the solid crust of a neutron star dramatically increases the viscous damping rate of the fluid r-modes. We improve previous estimates of this damping rate by including the effect of the…

Astrophysics · Physics 2009-10-31 Lee Lindblom , Benjamin J. Owen , Greg Ushomirsky

The self-consistent approach to the magnetic field evolution in neutron star cores, developed recently, is generalised to the case of superfluid and superconducting neutron stars. Applying this approach to the cold matter of neutron star…

High Energy Astrophysical Phenomena · Physics 2020-10-21 Mikhail E. Gusakov , Elena M. Kantor , Dmitry D. Ofengeim

We present first results of the non-linear evolution of rotating relativistic stars obtained with an axisymmetric relativistic hydrodynamics code in a fixed spacetime. As initial data we use stationary axisymmetric and perturbed…

General Relativity and Quantum Cosmology · Physics 2007-05-23 N. Stergioulas , J. A. Font , K. D. Kokkotas

We constrain the parameters of neutron superfluidity in the cores of neutron stars making use of the recently proposed effect of resonance stabilization of $r$-modes. To this end, we, for the first time, calculate the finite-temperature…

High Energy Astrophysical Phenomena · Physics 2020-10-21 Elena M. Kantor , Mikhail E. Gusakov , Vasiliy A. Dommes

The secular instability and nonlinear evolution of the m=2 f-mode (bar-mode) driven by gravitational radiation reaction in a rapidly rotating, newly formed neutron star are reviewed. There are two types of rotating bars which generate quite…

Astrophysics · Physics 2009-11-06 Dong Lai

The question is addressed whether stellar differentially rotating radiative zones (like the solar tachocline) excite nonaxisymmetric r-modes which can be observed. To this end the hydrodynamical stability of latitudinal differential…

Solar and Stellar Astrophysics · Physics 2015-05-13 L. L. Kitchatinov , G. Rüdiger

Analytic arguments have been advanced that the degree of differential rotation in a neutron star depends on whether the topology of the internal magnetic field is open or closed. To test this assertion, the ideal-magnetohydrodynamics solver…

High Energy Astrophysical Phenomena · Physics 2020-04-23 F. Anzuini , A. Melatos

We apply the model of flux expulsion from the superfluid and superconductive core of a neutron star, developed by Konenkov & Geppert (2000), both to neutron star models based on different equations of state and to different initial magnetic…

Astrophysics · Physics 2009-11-06 D. Konenkov , U. Geppert

Gravitational radiation tends to drive gravity modes in rotating neutron stars unstable. For an inviscid star, the instability sets in when the rotation frequency is about 0.7 times the corresponding mode frequency of the nonrotating star.…

Astrophysics · Physics 2009-09-25 Dong Lai

We study ambipolar diffusion in strongly magnetised neutron stars, with special focus on the effects of neutrino reaction rates and the impact of a superfluid/superconducting transition in the neutron star core. For axisymmetric magnetic…

High Energy Astrophysical Phenomena · Physics 2017-01-25 Andrea Passamonti , Taner Akgün , José A. Pons , Juan A. Miralles

An investigation is made of disk accretion of matter onto a rotating star with an aligned dipole magnetic field. A new aspect of this work is that when the angular velocity of the star and disk differ substantially we argue that the $\bf B$…

Astrophysics · Physics 2015-06-24 R. V. E. Lovelace , M. M. Romanova , G. S. Bisnovatyi-Kogan

We study the effect of rotation on the excitation of internal oscillation modes of a star by the external gravitational potential of its companion. Unlike the nonrotating case, there are difficulties with the usual mode decomposition for…

Astrophysics · Physics 2009-10-30 Dong Lai

Newly born neutron stars can present differential rotation, even if later it should be suppressed by viscosity or a sufficiently strong magnetic field. And in this early stage of its life, a neutron star is expected to have a strong…

General Relativity and Quantum Cosmology · Physics 2013-02-22 Cecilia Chirenti , Jozef Skakala , Shin'ichirou Yoshida

Simulations of magnetohydrodynamics convection in slowly rotating stars predict anti-solar differential rotation (DR) in which the equator rotates slower than poles. This anti-solar DR in the usual $\alpha \Omega$ dynamo model does not…

Solar and Stellar Astrophysics · Physics 2020-01-01 Bidya Binay Karak , Aparna Tomar , Vindya Vashishth

We have computed the eigenfrequencies of f-modes for a constant-rest-mass sequences of rapidly rotating relativistic inviscid stars in differential rotation. The frequencies have been calculated neglecting the metric perturbations (the…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Shin'ichirou Yoshida , Luciano Rezzolla , Shigeyuki Karino , Yoshiharu Eriguchi