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Related papers: On magnetized anisotropic stars

200 papers

The magnetic geometry of the surface magnetic fields of more than 55 cool stars have now been mapped using spectropolarimetry. In order to better understand these observations, we compare the magnetic field topology at different surface…

Solar and Stellar Astrophysics · Physics 2017-01-25 L. T. Lehmann , M. M. Jardine , A. A. Vidotto , D. H. Mackay , V. See , J. -F. Donati , C. P. Folsom , S. V. Jeffers , S. C. Marsden , J. Morin , P. Petit

We study the linear magneto-hydrodynamical behaviour of a Newtonian cosmology with a viscous magnetized fluid of finite conductivity and generalise the Jeans instability criterion. The presence of the field favors the anisotropic collapse…

Astrophysics · Physics 2009-11-13 L. Vlahos , C. G. Tsagas , D. Papadopoulos

Current models of magnetars require extremely strong magnetic fields to explain their observed quiescent and bursting emission, implying that the field strength within the star's outer crust is orders of magnitude larger than the dipole…

Solar and Stellar Astrophysics · Physics 2016-04-07 Konstantinos N. Gourgouliatos , Toby Wood , Rainer Hollerbach

We generalise the covariant Tolman-Oppenheimer-Volkoff equations proposed in arXiv:1709.02818 [gr-qc] to the case of static and spherically symmetric spacetimes with anisotropic sources. The extended equations allow a detailed analysis of…

General Relativity and Quantum Cosmology · Physics 2018-06-27 Sante Carloni , Daniele Vernieri

Magnetar magnetospheres gradually become twisted due to shearing by footpoint motion. The axisymmetric solutions for the force-free field with a power-law current model are calculated by taking into account general relativistic effects.…

High Energy Astrophysical Phenomena · Physics 2017-04-19 Yasufumi Kojima

Spectropolarimetric observations have been used to map stellar magnetic fields, many of which display strong bands of azimuthal fields that are toroidal. A number of explanations have been proposed to explain how such fields might be…

The generalized Gullstrand-Painleve geometry is investigated for expanding matter. Compared to other studies, we take into account an anisotropic stress tensor as the source of curvature with an equation of state resembling the MIT bag…

General Relativity and Quantum Cosmology · Physics 2025-07-01 Hristu Culetu

Axisymmetric magnetohydrodynamics (MHD) can be invoked for describing astrophysical magnetized flows and formulated to model stellar magnetospheres including main sequence stars (e.g. the Sun), compact stellar objects [e.g. magnetic white…

Solar and Stellar Astrophysics · Physics 2014-03-05 Lile Wang , Yu-Qing Lou

In this paper we will discuss charged stars with polytropic equation of state, where we will try to derive an equation analogous to the Lane-Emden equation. We will assume that these stars are spherically symmetric, and the electric field…

Astrophysics · Physics 2009-11-10 Rodrigo Picanco , Manuel Malheiro , Subharthi Ray

A physically realistic stellar model with a simple expression for the energy density and conformally flat interior is found. The relations between the different physical conditions are used without graphic proofs. It may represnet a real…

General Relativity and Quantum Cosmology · Physics 2018-04-26 B. V. Ivanov

Extremely magnetized neutron stars with magnetic fields as strong as $\sim 10^{15-16}$ G, or magnetars, have received considerable attention in the last decade due to their identification as a plausible source for Soft Gamma Repeaters and…

High Energy Astrophysical Phenomena · Physics 2015-06-18 A. G. Pili , N. Bucciantini , L. Del Zanna

We study the effects of anisotropic pressure on the properties of spherically symmetric, gravitationally bound objects. We consider the full general relativistic treatment of this problem and obtain exact solutions for various form of…

Astrophysics · Physics 2007-05-23 Krsna Dev , Marcelo Gleiser

The magnetar model and a solid quark star model for anomalous X-ray pulsars/soft gamma-ray repeaters (AXPs/SGRs) are discussed. Different manifestations of pulsar-like stars are speculated to be due to both their nature (e.g., mass and…

Astrophysics · Physics 2008-11-26 Renxin Xu

A flexible spectral code for the study of general relativistic magnetohydrodynamics is presented. Aiming at investigating the physics of slowly rotating magnetized compact stars, this new code makes use of various physically motivated…

General Relativity and Quantum Cosmology · Physics 2008-11-26 S. Bonazzola , L. Villain , M. Bejger

In this work we review the formalism normally used in the literature about the effects of density-dependent magnetic fields on the properties of neutron and quark stars, expose some ambiguities that arise and propose a way to solve the…

High Energy Astrophysical Phenomena · Physics 2015-08-06 Luiz L. Lopes , Debora P. Menezes

We construct two classes of the magnetohydrostatic equilibria of the axisymmetric flux tubes with twisted magnetic fields in the stratified solar atmosphere that span from the photosphere to the transition region. We built the models by…

Solar and Stellar Astrophysics · Physics 2021-03-31 S. Sen , A. Mangalam

The structure of the Einstein field equations describing the gravitational collapse of spherically symmetric isotropic fluids is analyzed here for general equations of state. A suitable system of coordinates is constructed which allows us,…

General Relativity and Quantum Cosmology · Physics 2015-03-24 Roberto Giambò , Giulio Magli

We employ the minimal geometric deformation approach to gravitational decoupling (MGD-decoupling) in order to generate an exact anisotropic and non-uniform version of the ultracompact Schwarzschild star, or 'gravastar', proposed by Mazur…

General Relativity and Quantum Cosmology · Physics 2020-09-25 J. Ovalle , C. Posada , Z. Stuchlík

We present Hall equilibrium solutions for neutron stars crusts containing toroidal and poloidal magnetic field. Some simple cases are solved analytically while more complicated configurations are found numerically through a Gauss-Seidel…

Solar and Stellar Astrophysics · Physics 2013-05-02 K. N. Gourgouliatos , A. Cumming , M. Lyutikov , A. Reisenegger

We show that any magnetostatic axially symmetric solution of the Einstein-Maxwell equations can be endowed with a specific charged fluid source of the Polanco et al type via a simple procedure requiring the knowledge of exclusively the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 I. Cabrera-Munguia , V. S. Manko