The High Energy Budget Allocations in Shocks and GRB

Understand

The statistical distribution of energies among particles responsible for long Gamma Ray Burst (GRB) emission is analyzed in light of recent results of the Fermi Observatory.

• The allsky flux, $F_{\gamma}$, recorded by the Gamma Ray Burst Monitor (GBM) is shown, despite its larger energy range, to be not significantly larger than that reported by the Burst and Transient Explorer (BATSE), suggesting a relatively small flux in the 3 - 30 MeV energy range.
• The present-day energy input rate in $\gamma$-rays recorded by the GBM from long GRB is found, assuming star-formation rates in the literature, to be $\dot W(0)=0.5 F_{\gamma} H/c = 5 \times 10^{42}\ \rm{erg/Mpc^3 yr}$.
• The Large Area Telescope (LAT) fluence, when observed, is about 5-10\% per decade of the total, in good agreement with the predictions of saturated, non-linear shock acceleration.