English
Related papers

Related papers: Axisymmetric spheroidal modes of neutron stars mag…

200 papers

In this third paper in a series on stable magnetic equilibria in stars, I look at the stability of axisymmetric field configurations and in particular at the relative strengths of the toroidal and poloidal components. Both toroidal and…

Astrophysics · Physics 2015-05-13 J. Braithwaite

We investigate the oscillation spectrum of rotating Newtonian neutron stars endowed with purely toroidal magnetic fields, using a time evolution code to evolve linear perturbations in the Cowling approximation. The background star is…

Solar and Stellar Astrophysics · Physics 2012-02-10 S. K. Lander , D. I. Jones , A. Passamonti

Context: Angular momentum (AM) transport models of stellar interiors require improvements to explain the strong extraction of AM from stellar cores that is observed with asteroseismology. One of the often invoked mediators of AM transport…

Solar and Stellar Astrophysics · Physics 2020-07-01 Jordan Van Beeck , Vincent Prat , Timothy Van Reeth , Stéphane Mathis , Dominic M. Bowman , Coralie Neiner , Conny Aerts

We study nonaxisymmetric perturbations of rotating relativistic stars. modeled as perfect-fluid equilibria. Instability to a mode with angular dependence $\exp(im\phi)$ sets in when the frequency of the mode vanishes. The locations of these…

General Relativity and Quantum Cosmology · Physics 2009-10-30 Nikolaos Stergioulas , John L. Friedman

The magnetic fields observed in Ap-stars, white dwarfs, and neutron stars are known to be stable for long times. However, the physical conditions inside the stellar interiors that allow these states are still a matter of research. It has…

Solar and Stellar Astrophysics · Physics 2022-10-05 L. Becerra , A. Reisenegger , J. A. Valdivia , M. Gusakov

The quasiperiodic oscillations found in the three giant flares of soft gamma-ray repeaters observed to date have been interpreted as crustal oscillations caused by a starquake following a dramatic rearrangement of the stellar magnetic…

High Energy Astrophysical Phenomena · Physics 2019-09-13 Gibran H. de Souza , Cecilia Chirenti

Using a metric perturbation method, we study gravitational waves from a test particle scattered by a spherically symmetric relativistic star. We calculate the energy spectrum and the waveform of gravitational waves for axial modes. Since…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Kazuhiro Tominaga , Motoyuki Saijo , Kei-ichi Maeda

Within the framework of Newtonian magneto-solid-mechanics, relying on equations appropriate for a perfectly conducting elastic continuous medium threaded by a uniform magnetic field, the asteroseismic model of a neutron star undergoing…

Astrophysics · Physics 2008-12-18 S. I. Bastrukov , G. -T. Chen , H. -K. Chang , I. V. Molodtsova , D. V. Podgainy

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 aim of this paper is to clarify the stabilities of neutron stars with strong toroidal magnetic fields against non-axisymmetric perturbation. The motivation comes from the fact that super magnetized neutron stars of $\sim 10^{15}$G,…

High Energy Astrophysical Phenomena · Physics 2012-08-21 Kenta Kiuchi , Shijun Yoshida , Masaru Shibata

We study $m=1$ oscillations and instabilities of magnetised neutron stars, by numerical time-evolution of linear perturbations of the system. The background stars are stationary equilibrium configurations with purely toroidal magnetic…

Solar and Stellar Astrophysics · Physics 2015-05-19 S. K. Lander , D. I. Jones

We study here the r-modes in the Cowling approximation of a slowly rotating and magnetized neutron star with a poloidal magnetic field, where we neglect any deformations of the spherical symmetry of the star. We were able to quantify the…

General Relativity and Quantum Cosmology · Physics 2013-11-27 Cecilia Chirenti , Jozef Skakala

We study magneto-elastic oscillations of highly magnetized neutron stars (magnetars) which have been proposed as an explanation for the quasi-periodic oscillations (QPOs) appearing in the decaying tail of the giant flares of soft gamma-ray…

Solar and Stellar Astrophysics · Physics 2015-06-11 Michael Gabler , Pablo Cerdá-Durán , José A. Font , Ewald Müller , Nikolaos Stergioulas

We investigate f-mode oscillations of static anisotropic stable neutron stars within the framework of full general relativity. We present equations governing unperturbed stellar structures and oscillations with an ansatz to account for the…

General Relativity and Quantum Cosmology · Physics 2025-02-25 Sushovan Mondal , Manjari Bagchi

Non-radial oscillation modes of a neutron star possess valuable information about its internal structure and nuclear physics. Starting from the quadrupolar order, such modes under general relativity are known as quasi-normal modes since…

General Relativity and Quantum Cosmology · Physics 2024-11-22 Shu Yan Lau , Siddarth Ajith , Victor Guedes , Kent Yagi

The Newtonian solid-mechanical theory of nodeless spheroidal and torsional of elastic seismic vibrations trapped in the crust of a quaking neutron star is outlined and applied to the modal classification of the quasi-periodic oscillations…

Astrophysics · Physics 2007-11-25 Sergey Bastrukov , Hsiang-Kuang Chang , Irina Molodtsova , Gwan-Ting Chen

We compute the axial quasi-normal modes of static neutron stars in scalar tensor theory. In particular, we employ various realistic equations of state including nuclear, hyperonic and hybrid matter. We investigate the fundamental curvature…

General Relativity and Quantum Cosmology · Physics 2018-08-29 Zahra Altaha Motahar , Jose Luis Blázquez-Salcedo , Burkhard Kleihaus , Jutta Kunz

In this present work, the axial quasi-normal modes of neutron stars, with a shift symmetric conformal coupling, are studied for different realistic equations of state. First, we derive the background equations in static and spherically…

General Relativity and Quantum Cosmology · Physics 2022-03-09 Hamza Boumaza

We study the cooling evolution of neutron stars with strong poloidal magnetic fields (with strength not far from observed values) using the full general relativity 2-dimensional \textit{Astreus} code, which solves consistently Einstein's…

High Energy Astrophysical Phenomena · Physics 2025-06-12 Rodrigo Negreiros , Jeffrey Peterson , Veronica Dexheimer

We study $r$-modes of a rotating magnetized neutron star, assuming a magnetic dipole field whose axis is aligned with the axis of rotation. We approach the problem by applying a singular perturbation theory to the oscillations of rotating…

Astrophysics · Physics 2009-11-10 Umin Lee