Near-horizon Structure of Escape Zones of Electrically Charged Particles around Weakly Magnetized Rotating Black Hole

0496239 - ASÚ 2019 RIV US eng J - Článek v odborném periodiku
Kopáček, Ondřej - Karas, Vladimír
Near-horizon Structure of Escape Zones of Electrically Charged Particles around Weakly Magnetized Rotating Black Hole.
Astrophysical Journal. Roč. 853, č. 1 (2018), č. článku 53. ISSN 0004-637X. E-ISSN 1538-4357
Grant CEP: GA MŠMT LD15061; GA ČR(CZ) GJ17-06962Y; GA ČR GB14-37086G
Institucionální podpora: RVO:67985815
Klíčová slova: acceleration of particles * black hole physics * chaos
Obor OECD: Astronomy (including astrophysics,space science)
Impakt faktor: 5.580, rok: 2018

We discuss the role of large-scale magnetic fields in transporting the charged particles and dust grains from the bound orbits in the equatorial plane of a rotating (Kerr) black hole and the resulting acceleration along trajectories escaping the system in a direction parallel to the symmetry axis (perpendicular to the accretion disk). We consider a specific scenario of destabilization of circular geodesics of initially neutral matter by charging (e.g., due to photoionization). Some particles may be set on escaping trajectories and attain relativistic velocity. The case of charged particles differs from charged dust grains by their charge-to-mass ratio, but the acceleration mechanism operates in a similar manner. It appears that the chaotic dynamics controls the outflow and supports the formation of near-horizon escape zones. We employ the technique of recurrence plots to characterize the onset of chaos in the outflowing medium. We investigate the system numerically and construct the basin-boundary plots, which show the location and the extent of the escape zones. The effects of black hole spin and magnetic field strength on the formation and location of escape zones are discussed, and the maximal escape velocity is computed.
Trvalý link: http://hdl.handle.net/11104/0289055