On the pair electromagnetic pulse of a black hole with electromagnetic structure
Abstract
We study the relativistically expanding electronpositron pair plasma formed by the process of vacuum polarization around an electromagnetic black hole (EMBH). Such processes can occur for EMBH's with mass all the way up to 6* 10(5M_sun) . Beginning with a idealized model of a ReissnerNordstrom EMBH with charge to mass ratio xi =0.1, numerical hydrodynamic calculations are made to model the expansion of the pairelectromagnetic pulse (PEM pulse) to the point that the system is transparent to photons. Three idealized special relativistic models have been compared and contrasted with the results of the numerically integrated general relativistic hydrodynamic equations. One of the three models has been validated: a PEM pulse of constant thickness in the laboratory frame is shown to be in excellent agreement with results of the general relativistic hydrodynamic code. It is remarkable that this precise model, starting from the fundamental parameters of the EMBH, leads uniquely to the explicit evaluation of the parameters of the PEM pulse, including the energy spectrum and the astrophysically unprecedented large Lorentz factors (up to 6* 10(3) for a 10(3) M_{sun} EMBH). The observed photon energy at the peak of the photon spectrum at the moment of photon decoupling is shown to range from 0.1 MeV to 4 MeV as a function of the EMBH mass. Correspondingly the total energy in photons is in the range of 10(52) to 10(54) ergs, consistent with observed gammaray bursts. In these computations we neglect the presence of baryonic matter which will be the subject of forthcoming publications.
 Publication:

Astronomy and Astrophysics
 Pub Date:
 October 1999
 arXiv:
 arXiv:astroph/9907030
 Bibcode:
 1999A&A...350..334R
 Keywords:

 BLACK HOLE PHYSICS;
 GAMMA RAYS: THEORY;
 GAMMA RAYS: BURSTS;
 GAMMA RAYS: OBSERVATIONS;
 Astrophysics
 EPrint:
 11 pages, 9 figures and A&