Refreshed shocks: forward shock model. Left panel: initial distribution of the Lorentz factor (lower part) and kinetic power (upper part) in the flow as a function of injection time t_inj. Right panel: synthetic light curves at 2 eV (black, dotted line) and 10 keV (gray, dotted line) compared to the data from Perley et al. (2009). The kinetic energies injected in the spike and extended emission components are  erg and . We adopt , p = 2.5 in the shocked external medium together with n = 10^-3 cm^-1 and z = 0.5. The steeper thin lines at late times correspond to a conical jet (seen on-axis) of opening angle θ_jet = 0.06 rad.