High-energy emission: spectra. The time-integrated spectrum (0–15 s) is plotted from the keV to the GeV range for the same cases as in Fig. 18. Top left panel: reference Cases A and B. Bottom left panel: Cases A and B with a varying accelerated electron fraction ζ. Top right panel: Case B with a sharp initial distribution of the Lorentz factor (see text) and a constant or a varying accelerated electron fraction ζ. Bottom right panel: Case B with a constant ejected mass flux (see text) and a constant or a varying accelerated electron fraction ζ.