Oblique magnetic fields and the role of frame dragging
arXiv:1901.06499 · doi:10.1002/asna.201913569
Abstract
Magnetic null points can develop near the ergosphere boundary of a rotating black hole by the combined effects of strong gravitational field and the frame-dragging mechanism. The electric component does not vanish in the magnetic null and an efficient process or particle acceleration can occur. The situation is relevant for starving (low-accretion-rate, such as the Milky Way's supermassive black hole) nuclei of some galaxies which exhibit only episodic accretion events. The presence of the magnetic field field of an external origin is an important aspect. We propose that such conditions can develop when a magnetized neutron star approaches the supermassive black hole during late stages of its inspiral motion. The field lines of the neutron star dipole thread the black hole's event horizon and change rapidly their connectivity. We put in comparison the case of a dipole-type magnetic field of a sinking and orbiting star near a non-rotating black hole, and the near-horizon structure of an asymptotically uniform magnetic field of a distant source near a fast-rotating black hole. Although the two cases are qualitatively different from each other, they both develop magnetically neutral null points near the event horizon.
arXiv comment5 pages, 3 figures; to appear in Proceedings of IWARA2018 - 8th International Workshop on Astronomy and Relativistic Astrophysics (Ollantaytambo, 8-15 September 2018), in preparation
References in corpus (13)
- Stationary Black Holes: Uniqueness and Beyond
- Surface Brightness Profile of the Milky Way's Nuclear Star Cluster
- Masses and Scaling Relations for Nuclear Star Clusters, and their Coexistence with Central Black Holes
- Three-dimensional magnetic reconnection regimes: A review
- Off-equatorial orbits in strong gravitational fields near compact objects -- II: halo motion around magnetic compact stars and magnetized black holes
- Near-horizon structure of escape zones of electrically charged particles around weakly magnetized rotating black hole
- General-relativistic electromagnetic fields around a slowly rotating neutron star: stationary vacuum solutions
- Influence of frame-dragging on magnetic null points near rotating black hole
- Oblique magnetic fields and the role of frame dragging near rotating black hole
- Coupled axisymmetric pulsar magnetospheres
- Null Points in the Magnetosphere of a Plunging Neutron Star
- Regular and chaotic motion in general relativity: The case of an inclined black hole magnetosphere
- Oblique magnetic fields and the role of frame dragging