4 The GRB - afterglow connection

We can put the above numbers in the context of a standard fireball internal shock scenario and make some rough

predictions on the evolution of the shell through the different phases: from the initial free-expansion fireball phase, to the late time blast wave (snow-plow) phase, using the analytic solutions of Piran et al. (1993) and Blandford & McKee (1976). In particular, the shell parameters derived above for the GRB phase can be used to predict the subsequent evolution parameters of the optical-radio afterglows which are associated with the blast wave phase. Hence the SCC model is highly predictive in that it tightly connects the GRB spectral evolution parameters to the afterglow parameters once the ISM/CBM density and the proton loading of the ejecta shell are specified.