Table of Contents
Journal of Thermodynamics
Volume 2012 (2012), Article ID 791870, 6 pages
http://dx.doi.org/10.1155/2012/791870
Research Article

Relativistic Accretion into a Reissner-Nordström Black Hole Revisited

Laboratoire Cassiopée-UMR 6202, Observatoire de la Côte d'Azur, University of Nice-Sophia Antipolis, BP 4222, 06304 Nice, Cedex 4, France

Received 20 June 2011; Revised 26 September 2011; Accepted 28 September 2011

Academic Editor: Y. Peles

Copyright © 2012 J. A. de Freitas Pacheco. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The accretion of relativistic and nonrelativistic fluids into a Reissner-Nordström black hole is revisited. The position of the critical point, the flow velocity at this point, and the accretion rate are only slightly affected with respect to the Schwarzschild case when the fluid is nonrelativistic. On the contrary, relativistic fluids cross the critical point always subsonically. In this case, the sonic point is located near the event horizon, which is crossed by the fluid with a velocity less than the light speed. The accretion rate of relativistic fluids by a Reissner-Nordström black hole is reduced with respect to those estimated for uncharged black holes, being about 60% less for the extreme case (charge-to-mass ratio equal to one).