Near‐horizon structure of escape zones of electrically charged particles around weakly magnetized rotating black hole: Case of oblique magnetosphere

Abstract

We study the effects of large-scale magnetic fields on the dynamics of charged particles near a rotating black hole. We consider a scenario in which the initially neutral particles on geodesic orbits in the equatorial plane become ionized, and hence they are destabilized by the charging process. Fraction of charged particles are then accelerated out of the equatorial plane and then follow jet-like trajectories with relativistic velocities. We explore nonaxisymmetric systems in which the magnetic field is inclined with respect to the black hole spin. We study the system numerically in order to locate the zones of escaping trajectories and compute the terminal escape velocity. By breaking the axial symmetry, we notice increasing fraction of unbound orbits which allow for acceleration to ultrarelativistic velocities.

On Innermost Stable Spherical Orbits near a Rotating Black Hole: A Numerical Study of the Particle Motion near the Plunging Region

“…For the case of circular orbits (upper-left panel of Figure 13) the distribution of different orbits in these regions appears random, while it becomes more organized for spherical orbits (Q > 0), and large escape zones also develop here. Especially in Figures 14 and 15, the structures in these regions may resemble fractal geometry encountered in analogous plots of escape zones in a previously studied nonintegrable system (Kopáček & Karas 2020;Karas & Kopáček 2021). Nevertheless, since here we investigate a fully integrable system, these unexpected features associated with deterministic chaos are necessarily of a numerical origin, i.e., caused by numerical errors of the integration.…”

“…In our previous studies (Kopáček & Karas 2018b, we investigated a different dynamical system with escapes Karas & Kopáček 2021) by a straightforward, yet effective, approach based on escapeboundary plots. Such a graphic representation of the dynamics is inspired by standard basin-boundary plots, which illustrate the basins of the attraction of attractors in systems with dissipation.…”

Magnetized Black Holes: Interplay between Charge and Rotation

“…In the case of B > 1 a special effect of chaotic scattering can be relevant [36,37] when the ionized particle can be accelerated along the magnetic field lines after a period of chaotic motion that decreases with increasing magnetic parameter [38]. In such situations, the magnetic Penrose process could be realized with extremely high efficiency.…”

Magnetized black holes: the role of rotation, boost, and accretion in twisting the field lines and accelerating particles

“…Initial locations of escaping particles form escape zones whose emergence and evolution with respect to the parameters of the system was discussed in our previous papers. 1,2,4 Efficiency of the acceleration mechanism was quantified by the final Lorentz factor of escaping particles leading to the conclusion that also ultrarelativistic velocities with very high energies may be achieved within the non-axisymmetric model.…”

“…In particular, the number of escaping orbits generally increases and acceleration to ultrarelativistic energies becomes possible in the oblique magnetosphere. 2,4 Furthermore, 5 by employing a boost transformation of the system into a frame in translation motion, we explored the electromagnetic aspects of the linear (kick) velocity of the black hole. Refer to enlightening discussions by various authors 6,7 and see also the relevant context of these solutions.…”