The fall of the shell of dust on to a rotating black hole.
Abstract
The motion of particles falling radially from rest at infinity with zero total angular momentum on to a rotating (Kerr) black hole is studied. The shell of such particles, initially spherical, becomes prolate along the axis of symmetry during the fall onto a rotating hole. The shape of the shell from the viewpoint of distant observers is studied by means of the photons moving along the (non-shearing) geodesics of the outgoing principal null congruence. The approach of the particles towards the horizon in terms of the arrival times of these photons to a distant observer, the redshift of the radiation and its intensity show dependence exponentially on the observer's proper time as in the non-rotating case, however the characteristic e-folding times become infinite as the hole's angular momentum approaches the extreme value. In the case of an extreme Kerr black hole these exponential laws go over into power laws.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- May 1976
- DOI:
- 10.1093/mnras/175.2.381
- Bibcode:
- 1976MNRAS.175..381B
- Keywords:
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- Black Holes (Astronomy);
- Cosmic Dust;
- Interstellar Matter;
- Particle Motion;
- Stellar Rotation;
- Binary Stars;
- Celestial Geodesy;
- Equations Of Motion;
- Particle Trajectories;
- Photons;
- Red Shift;
- Relativistic Theory;
- Astrophysics