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The Energy of Gamma-Ray Bursts

Tsvi Piran
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Abstract

The energy of a Gamma-Ray Burst is one of the most interesting factors that can help determining the origin of these mysterious explosions. After the discovery that GRBs are cosmological it was thought, for a while that they are standard candles releasing $\sim 10^{51}$ergs. Redshift measurements that followed the discovery of GRB afterglow revealed that GRBs are (i) further than what was initially believed and (ii) have a very wide luminosity function. Some bursts revealed an enormous energy release with a record estimate of $ 1.4 \times 10^{54}$ergs for GRB990123. The energy budget was stretched even further when it was suggested that the conversion efficiency of producing gamma-rays is low. The realization that GRBs are beamed changed this perspective and brought the energy budget of GRBs down back to a "modest" $\sim 5 \times 10^{50}$ergs. I discuss here various estimates showing that GRB energy is narrowly distributed and discuss the implications of this conclusion to GRB models.

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Tsvi Piran. 2001-11-15. The Energy of Gamma-Ray Bursts. https://arxiv.org/abs/astro-ph/0111314

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