On the interpretation of the burst structure of gamma-ray bursts

Given the very accurate data from the BATSE and the Rossi X-Ray Timing Expl orer and Chandra satellites, we use GRB 991216 as a prototypical case to te st the theory that links the origin of the energy of gamma-ray bursts (GRBs ) to the extractable energy of electromagnetic black holes (EMBHs). The fit of the afterglow fixes the only two free parameters of the model and leads to a new paradigm for the interpretation of the burst structure (the IBS p aradigm). It leads as well to a reconsideration of the relative roles of th e afterglow and burst in GRBs by defining two new phases in this complex ph enomenon: (1) the injector phase, giving rise to the proper GRB, and (2) th e beam-target phase, giving rise to the extended afterglow peak emission an d to the afterglow. Such differentiation leads to a natural possible explan ation of the bimodal distribution of GRBs observed by BATSE. The agreement with the observational data in regions extending from the horizon of the EM BH all the way out to the distant observer confirms the uniqueness of the m odel.