Search of the Energetic Gamma Ray Experiment Telescope (EGRET) Data for High Energy Gamma Ray Microsecond Bursts
Session 67 -- Cosmology and Distance Indicators
Oral presentation, Thursday, January 13, 2:15-3:45, Crystal Forum Room (Crystal City Marriott)

## [67.04] Search of the Energetic Gamma Ray Experiment Telescope (EGRET) Data for High Energy Gamma Ray Microsecond Bursts

C. E. Fichtel, D. L. Bertsch, R. C. Hartman, S. D. Hunter, D. J. Thompson (NASA/GSFC), B. L. Dingus, P. Sreekumar (NASA/GSFC, USRA), J. R. Mattox (NASA/GSFC, CSC), G. Kanbach, H. A. Mayer-Hasselwander, C. von Montigny (MPE), Y. C. Lin, P. F. Michelson, P. L. Nolan (Stanford Univ.), and E. Schneid (Grumman)

Hawking (1974) and Page and Hawking (1976) investigated theoretically the possibility of detecting high energy gamma rays produced by the quantum-mechanical decay of a small black hole created in the early Universe. They concluded, that at the very end of the life of the small black hole, it would radiate a burst of gamma rays peaked near 250 MeV with a total energy of about 10$^{34}$ ergs in the order of a microsecond or less. The characteristics of a black hole are determined by laws of physics beyond current knowledge so whether this theory, or another, is correct is unknown. Earlier attempts by the SAS-2 high energy gamma ray telescope and ground-based vvery high energy gamma ray have set limits on these possible bursts. The Compton Observatory EGRET has the capability of detecting such bursts at a much fainter level than SAS-2, and a continuing search of the EGRET data is being made. None have yet been seen.

\noindent{Hawking, S. W., 1974, Nature, 248, 30}

\noindent{Page, D. N., and Hawking, S. P., 1976, ApJ, 206, 1}