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Related papers: Non-dipolar magnetic fields in Ap stars

200 papers

Disk accretion to rotating stars with complex magnetic fields is investigated using full three-dimensional magnetohydrodynamic (MHD) simulations. The studied magnetic configurations include superpositions of misaligned dipole and quadrupole…

Astrophysics · Physics 2009-11-13 M. Long , M. M. Romanova , R. V. E. Lovelace

Many types of stars show periodic variations of radius and brightness, which are commonly referred to as `stellar pulsations'. Observed pulsational characteristics are determined by fundamental stellar parameters. Consequently,…

Astrophysics · Physics 2016-08-30 O. Kochukhov

Both neutron stars and strange stars are capable of supporting fast rotations observed in pulsars. On the basis of this it has been argued that some of the pulsars could be strange stars. We investigate whether strange stars can sustain…

Astrophysics · Physics 2007-05-23 Sushan Konar

There has been sufficient observational indication suggesting a causal connection between the binary history of neutron stars and the evolution of their magnetic field. In particular, it is believed that the generation of the low-field…

Astrophysics · Physics 2007-05-23 Sushan Konar

Fast rotating cool stars are characterised by high magnetic activity levels and frequently show dark spots up to polar latitudes. Their distinctive surface distributions of magnetic flux are investigated in the context of the solar-stellar…

Astrophysics · Physics 2008-11-26 V. Holzwarth

In this paper we discuss the spin-equilibrium of accreting neutron stars in LMXBs. We demonstrate that, when combined with a naive spin-up torque, the observed data leads to inferred magnetic fields which are at variance with those of…

Astrophysics · Physics 2009-11-10 N. Andersson , K. Glampedakis , B. Haskell , A. L. Watts

The configuration of the magnetic field in the interior of a neutron star is mostly unknown from observations. Theoretical models of the interior magnetic field geometry tend to be oversimplified to avoid mathematical complexity and tend to…

High Energy Astrophysical Phenomena · Physics 2020-10-07 Prasanta Bera , D. I. Jones , Nils Andersson

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

Relativistic stars are endowed with intense electromagnetic fields but are also subject to oscillations of various types. We here investigate the impact that oscillations have on the electric and magnetic fields external to a relativistic…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Luciano Rezzolla , Bobomurat J. Ahmedov

We present the first 3D fully coupled magneto-thermal simulations of neutron stars (including the most realistic background structure and microphysical ingredients so far) applied to a very complex initial magnetic field topology in the…

High Energy Astrophysical Phenomena · Physics 2023-06-28 Clara Dehman , Daniele Viganò , Stefano Ascenzi , Jose A. Pons , Nanda Rea

In this paper we investigate the evolution of binary neutron stars, namely, their magnetic field, spin, and orbital evolution. The core of a neutron star is considered to be a superfluid, superconductor type II. Flux expulsion of the…

Solar and Stellar Astrophysics · Physics 2009-05-05 Shohreh Abdolrahimi

According to our understanding of stellar evolution, early-type stars have radiative envelopes and convective cores due to a steep temperature gradient produced by the CNO cycle. Some of these stars (mainly, the subclasses Ap and Bp) have…

Solar and Stellar Astrophysics · Physics 2023-03-21 J. P. Hidalgo , P. J. Käpylä , C. A. Ortiz-Rodríguez , F. H. Navarrete , B. Toro , D. R. G. Schleicher

In the context of the white dwarf asteroseismology, we investigate vibrational properties of a non-convective solid star with an axisymmetric purely toroidal intrinsic magnetic field of two different shapes. Focus is laid on regime of…

Solar and Stellar Astrophysics · Physics 2015-05-18 Irina Molodtsova , Sergey Bastrukov , Kuan-Ting Chen , Hsiang-Kuang Chang

Models of rotating relativistic stars with a toroidal magnetic field have been computed for a sample of eight equations of state of cold dense matter. Non-rotating models admit important levels of magnetization and quadrupole distortion…

General Relativity and Quantum Cosmology · Physics 2015-06-18 Joachim Frieben , Luciano Rezzolla

Some contracting or expanding stars are thought to host a large-scale magnetic field in their radiative interior. By interacting with the contraction-induced flows, such fields may significantly alter the rotational history of the star.…

Solar and Stellar Astrophysics · Physics 2022-05-18 B. Gouhier , L. Jouve , F. Lignières

Stationary and axisymmetric solutions of relativistic rotating stars with strong mixed poloidal and toroidal magnetic fields are obtained numerically. Because of the mixed components of the magnetic field, the underlying stationary and…

High Energy Astrophysical Phenomena · Physics 2014-11-13 Koji Uryu , Eric Gourgoulhon , Charalampos Markakis , Kotaro Fujisawa , Antonios Tsokaros , Yoshiharu Eriguchi

The properties of the extremely strong magnetic fields of neutron stars affect in a unique way their evolution and the associated phenomenology. Due to the lack of constraints from direct observations, our understanding of the magnetic…

High Energy Astrophysical Phenomena · Physics 2015-06-22 Riccardo Ciolfi

Non-axisymmetric oscillations of differentially rotating stars are studied using both slow rotation and Cowling approximation. The equilibrium stellar models are relativistic polytropes where differential rotation is described by the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Andrea Passamonti , Adamantios Stavridis , Kostas Kokkotas

We present the result of a highly sensitive spectropolarimetric study dedicated to intermediate mass stars. We report the detection of sub-gauss surface magnetic fields on the normal, rapidly-rotating A-type star Vega and on the…

Solar and Stellar Astrophysics · Physics 2015-05-30 P. Petit , F. Lignières , G. A. Wade , M. Aurière , D. Alina , T. Böhm , A. Oza

Some Ap stars with strong magnetic fields pulsate in high order p-modes; they are called roAp (rapidly oscillating Ap) stars. The p-mode frequencies are modified by the magnetic fields. Although the large frequency separations are hardly…

Solar and Stellar Astrophysics · Physics 2015-06-17 Hideyuki Saio