Beaming in Gamma-Ray Bursts: Evidence for a Standard Energy Reservoir

D. A. Frail; S. R. Kulkarni; R. Sari; S. G. Djorgovski; J. S. Bloom; T. J. Galama; D. E. Reichart; E. Berger; F. A. Harrison; P. A. Price; S. A. Yost; A. Diercks; R. W. Goodrich; F. Chaffee

doi:10.1086/338119

arXiv · astro-ph/0102282

Beaming in Gamma-Ray Bursts: Evidence for a Standard Energy Reservoir

D. A. Frail·S. R. Kulkarni·R. Sari·S. G. Djorgovski·J. S. Bloom·T. J. Galama·D. E. Reichart·E. Berger·F. A. Harrison·P. A. Price·S. A. Yost·A. Diercks·R. W. Goodrich·F. Chaffee

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Abstract

Gamma-ray bursts (GRBs) are the most brilliant objects in the Universe but efforts to estimate the total energy released in the explosion -- a crucial physical quantity -- have been stymied by their unknown geometry: spheres or cones. We report on a comprehensive analysis of GRB afterglows and derive their conical opening angles. We find that the gamma-ray energy release, corrected for geometry, is narrowly clustered around 5x10**50 erg. We draw three conclusions. First, the central engines of GRBs release energies that are comparable to ordinary supernovae, suggesting a connection. Second, the wide variation in fluence and luminosity of GRBs is due entirely to a distribution of opening angles. Third, only a small fraction of GRBs are visible to a given observer and the true GRB rate is at least a factor of 500 times larger than the observed rate.

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D. A. Frail, S. R. Kulkarni, R. Sari, S. G. Djorgovski, J. S. Bloom, T. J. Galama, D. E. Reichart, E. Berger, F. A. Harrison, P. A. Price, S. A. Yost, A. Diercks, R. W. Goodrich, F. Chaffee. 2001-02-15. Beaming in Gamma-Ray Bursts: Evidence for a Standard Energy Reservoir. https://doi.org/10.1086/338119

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