Magneto-elastic torsional oscillations of magnetars
arXiv:1011.5406 · doi:10.1088/1742-6596/283/1/012013
Abstract
We extend a general-relativistic ideal magneto-hydrodynamical code to include the effects of elasticity. Using this numerical tool we analyse the magneto-elastic oscillations of highly magnetised neutron stars (magnetars). In simulations without magnetic field we are able to recover the purely crustal shear oscillations within an accuracy of about a few per cent. For dipole magnetic fields between 5 x 10^13 and 10^15 G the Alfvén oscillations become modified substantially by the presence of the crust. Those quasi-periodic oscillations (QPOs) split into three families: Lower QPOs near the equator, Edge QPOs related to the last open field line and Upper QPOs at larger distance from the equator. Edge QPOs are called so because they are related to an edge in the corresponding Alfvén continuum. The Upper QPOs are of the same kind, while the Lower QPOs are turning-point QPOs, related to a turning point in the continuous spectrum.
6 pages, 1 figure, 1 table, Proceedings of NEB14, to appear in J. Phys.: Conf. Ser
References in corpus (13)
- Neutron Star Asteroseismology. Axial Crust Oscillations in the Cowling Approximation
- Torsional Oscillations of Relativistic Stars with Dipole Magnetic Fields
- QPOs during magnetar flares are not driven by mechanical normal modes of the crust
- On the theory of magnetar QPOs
- Constraints on Neutron Star Crusts From Oscillations in Giant Flares
- Alfvén QPOs in Magnetars
- Neutron star oscillations and QPOs during magnetar flares
- A new general relativistic magnetohydrodynamics code for dynamical spacetimes
- Ekman layer damping of r-modes revisited
- Axisymmetric oscillations of magnetic neutron stars
- Axisymmetric toroidal modes of magnetized neutron stars
- Relativistic mechanics of neutron superfluid in (magneto) elastic star crust
- Elastic stars in general relativity: IV. Axial perturbations