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Related papers: The oscillation and stability of differentially ro…

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The impact of the combination of rotation and magnetic fields on oscillations of stellar fluids is still not well known theoretically. It mixes Alfv\'en and inertial waves. Neutron stars are a place where both effects may be at work. We…

High Energy Astrophysical Phenomena · Physics 2015-05-30 S. Abbassi , M. Rieutord , V. Rezania

The effects that the structure of a neutron star would have on the gravitational emission of a binary system are studied in a perturbative regime, and in the frequency domain. Assuming that a neutron star is perturbed by a point mass moving…

General Relativity and Quantum Cosmology · Physics 2011-07-19 J. A. Pons , E. Berti , L. Gualtieri , G. Miniutti , V. Ferrari

Thermal emission from a rotating, supermassive star will cause the configuration to contract slowly and spin up. If internal viscosity and magnetic fields are sufficiently weak, the contracting star will rotate differentially. For each of…

Astrophysics · Physics 2009-10-31 Kimberly C. B. New , Stuart L. Shapiro

The evolution of the r-mode instability is likely to be accompanied by secular kinematic effects which will produce differential rotation with large scale drifts of fluid elements, mostly in the azimuthal direction. As first discussed by…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Luciano Rezzolla , Frederick L. Lamb , Dragoljub Markovic , Stuart L. Shapiro

We study the low T/W instability associated with the f-mode of differentially rotating stars. Our stellar models are described by a polytropic equation of state and the rotation profile is given by the standard j-constant law. The…

Solar and Stellar Astrophysics · Physics 2015-06-22 Andrea Passamonti , Nils Andersson

A set of theoretical mass-radius relations for rigidly rotating neutron stars with exotic cores, obtained in various theories of dense matter, is reviewed. Two basic observational constraints are used: the largest measured rotation…

High Energy Astrophysical Phenomena · Physics 2016-04-20 P. Haensel , M. Bejger , M. Fortin , J. L. Zdunik

Neutron stars are the most compact horizonless objects in the Universe, exhibiting the strongest known magnetic fields. They are potential sources of coincident gravitational waves and electromagnetic radiation across the entire spectrum.…

High Energy Astrophysical Phenomena · Physics 2025-08-29 Fabrizio Venturi Piñas , Anson Ka Long Yip , Patrick Chi-Kit Cheong , Milton Ruiz

We study the dynamical instability against bar-mode deformation of differentially rotating stars. We performed numerical simulation and linear perturbation analysis adopting polytropic equations of state with the polytropic index $n=1$. It…

General Relativity and Quantum Cosmology · Physics 2010-11-19 Masaru Shibata , Shigeyuki Karino , Yoshiharu Eriguchi

Gravitational radiation (GR) drives an instability in certain modes of rotating stars. This instability is strong enough in the case of the r-modes to cause their amplitudes to grow on a timescale of tens of seconds in rapidly rotating…

Astrophysics · Physics 2007-05-23 Lee Lindblom

The back-bending phenomenon for compact stars is studied by means of analytical equations of state, for both constant-pressure phase transitions and the transitions through the mixed-phase region. We restrict ourselves to the case of normal…

Astrophysics · Physics 2007-05-23 J. L. Zdunik , M. Bejger , P. Haensel , E. Gourgoulhon

We initiate numerical studies of differentially rotating magnetised (proto) neutron stars by studying - through construction from first principles - the coupling between an assumed differential rotation and an impressed magnetic field. For…

Astrophysics · Physics 2007-05-23 A. V. Thampan

We investigate the non-linear coupling between radial and non-radial oscillations of static spherically symmetric neutron stars as a possible mechanism for the generation of gravitational waves that may lead to observable signatures. In…

General Relativity and Quantum Cosmology · Physics 2009-11-11 A. Passamonti , M. Bruni , L. Gualtieri , A. Nagar , C. F. Sopuerta

We carry out 3-D numerical simulations of the dynamical instability in rapidly rotating stars initially modeled as polytropes with n = 1.5, 1.0, and 0.5. The calculations are done with a SPH code using Newtonian gravity, and the…

General Relativity and Quantum Cosmology · Physics 2010-11-19 Janet L. Houser , Joan M. Centrella

In this paper we study the effects of rotation on the frequencies of the quasi-normal modes of a proto-neutron star (PNS) born in a gravitational collapse during the first minute of life. Our analysis starts a few tenths of seconds after…

Astrophysics · Physics 2009-11-10 V. Ferrari , L. Gualtieri , J. A. Pons , A. Stavridis

In the present work, we study the radial and non-radial perturbative stability of neutron stars in which the matter is disformally coupled to the metric. First, we derive the gravitational and the fluid equations of the neutron star in a…

General Relativity and Quantum Cosmology · Physics 2023-08-08 Hamza Boumaza

We examine the stability of standing, spherical accretion shocks. Accretion shocks arise in core collapse supernovae (the focus of this paper), star formation, and accreting white dwarfs and neutron stars. We present a simple analytic model…

Astrophysics · Physics 2009-11-07 John M. Blondin , Anthony Mezzacappa , Christine DeMarino

In the present paper we investigate self-consistently slowly rotating neutron and strange stars in R-squared gravity. For this purpose we first derive the equations describing the structure of the slowly rotating compact stars in…

General Relativity and Quantum Cosmology · Physics 2015-06-22 Kalin V. Staykov , Daniela D. Doneva , Stoytcho S. Yazadjiev , Kostas D. Kokkotas

In this paper we review the basics of magneto-rotational properties of neutron stars focusing on spin-up/spin-down behavior at different evolutionary stages. The main goal is to provide equations for the spin frequency changes in various…

High Energy Astrophysical Phenomena · Physics 2024-02-08 P. Abolmasov , A. V. Biryukov , S. B. Popov

Detecting and understanding rotation in stellar interiors is nowadays one of the unsolved problems in stellar physics. Asteroseismology has been able to provide insights on rotation for the Sun, solar-like stars, and compact objects like…

Solar and Stellar Astrophysics · Physics 2021-06-24 A. Ramón-Ballesta , A. García Hernández , J. C. Suárez , J. R. Rodón , J. Pascual-Granado , R. Garrido

Internal waves propagating in stellar radiative zones can lead to efficient angular momentum transport, that should occur throughout the whole lifetime of stars. They thus play a key role in shaping the internal rotation profile of these…

Solar and Stellar Astrophysics · Physics 2018-11-08 Q. André , S. Mathis , L. Amard