Electromagnetic fields in the exterior of an oscillating relativistic star -- II. Electromagnetic damping
arXiv:1605.01709 · doi:10.1093/mnras/stw864
Abstract
An important issue in the asteroseismology of compact and magnetized stars is the determination of the dissipation mechanism which is most efficient in damping the oscillations when these are produced. In a linear regime and for low-multipolarity modes these mechanisms are confined to either gravitational-wave or electromagnetic losses. We here consider the latter and compute the energy losses in the form of Poynting fluxes, Joule heating and Ohmic dissipation in a relativistic oscillating spherical star with a dipolar magnetic field in vacuum. While this approach is not particularly realistic for rapidly rotating stars, it has the advantage that it is fully analytic and that it provides expressions for the electric and magnetic fields produced by the most common modes of oscillation both in the vicinity of the star and far away from it. In this way we revisit and extend to a relativistic context the classical estimates of McDermott et al. Overall, we find that general-relativistic corrections lead to electromagnetic damping time-scales that are at least one order of magnitude smaller than in Newtonian gravity. Furthermore, with the only exception of (gravity) modes, we find that (fundamental), (pressure), (interface) and (shear) modes are suppressed more efficiently by gravitational losses than by electromagnetic ones.
21 pages, 1 figure; for paper I see arXiv:gr-qc/0406018; MNRAS in press
References in corpus (26)
- Magnetars: the physics behind observations
- 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
- Elastic or magnetic? A toy model for global magnetar oscillations with implications for QPOs during flares
- Alfvén QPOs in Magnetars
- Gravitational wave asteroseismology with fast rotating neutron stars
- Neutron star oscillations and QPOs during magnetar flares
- Oscillations of rapidly rotating relativistic stars
- Hydromagnetic Instabilities in Neutron Stars
- Variability from Nonaxisymmetric Fluctuations Interacting with Standing Shocks in Tilted Black Hole Accretion Disks
- Quasi-Periodic Oscillations in Short Recurring Bursts of the magnetars SGR 1806-20 and SGR 1900+14 Observed With RXTE
- Alfvén Polar Oscillations of Relativistic Stars
- Axisymmetric oscillations of magnetic neutron stars
- Modulating the magnetosphere of magnetars by internal magneto-elastic oscillations
- Differential rotation of the unstable nonlinear r-modes
- High frequency oscillations during magnetar flares
- Oscillation Driven Magnetospheric Activity In Pulsars
- The Magnetosphere of Oscillating Neutron Stars in General Relativity
- A Pulsational Model for the Orthogonal Polarization Modes in Radio Pulsars
- The influence of differential rotation on the detectability of gravitational waves from the r-mode instability
- A Quantitative Non-radial Oscillation Model for the Subpulses in PSR B0943+10
- Torsional Oscillations of Slowly Rotating Relativistic Stars
- Axisymmetric toroidal modes of general relativistic magnetized neutron star models
- Discovery of Quasi-Periodic Oscillations in the Recurrent Burst Emission from SGR 1806-20
Cited by in corpus (6)
- Theory of pulsar magnetosphere and wind
- Continuous gravitational wave from magnetized white dwarfs and neutron stars: possible missions for LISA, DECIGO, BBO, ET detectors
- Electromagnetic fields of slowly rotating magnetized compact stars in conformal gravity
- On the Persistence of QPOs During the SGR 1806-20 Giant Flare
- Multipolar electromagnetic fields around neutron stars: general-relativistic vacuum solutions
- Methods for relativistic self-gravitating fluids: From binary neutron stars to black hole-disks and magnetized rotating neutron stars