Given the very accurate data from the BATSE and the Rossi X-Ray Timing Explorer and Chandra satellites, we use GRB 991216 as a prototypical case to test 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 paradigm). It leads as well to a reconsideration of the relative roles of the afterglow and burst in GRBs by defining two new phases in this complex phenomenon: (1) the injector phase, giving rise to the proper GRB, and (2) the beam-target phase, giving rise to the extended afterglow peak emission and to the afterglow. Such differentiation leads to a natural possible explanation of the bimodal distribution of GRBs observed by BATSE. The agreement with the observational data in regions extending from the horizon of the EMBH all the way out to the distant observer confirms the uniqueness of the model. Subject headings: black hole physics -gamma rays: bursts -supernovae: generalThe most decisive tool in the identification of the energetics of gamma-ray bursts (GRBs) has been the discovery by BeppoSAX of the afterglow phenomenon. In this Letter, we show how the afterglow data can be fitted using the theory that relates the GRB energy to the extraction process of the electromagnetic energy of a black hole endowed with electromagnetic structure (the EMBH model).

The GRB 991216 and its relevant data acquired from the BATSE experiment and RXTE and Chandra satellites are used as a prototypical case to test the theory linking the origin of gamma ray bursts (GRBs) to the process of vacuum polarization occurring during the formation phase of a black hole endowed with electromagnetic structure (EMBH). The relative space-time transformation paradigm (RSTT paradigm) is presented. It relates the observed signals of GRBs to their past light cones, defining the events on the worldline of the source essential for the interpretation of the data. Since GRBs present regimes with unprecedently large Lorentz γ factor, also sharply varying with time, particular attention is given to the constitutive equations relating the four time variables: the comoving time, the laboratory time, the arrival time at the detector, duly corrected by the cosmological effects. This paradigm is at the very foundation of any possible interpretation of the data of GRBs.

Using GRB 991216 as a prototype, it is shown that the intensity substructures observed in what is generally called the "prompt emission" in gamma ray bursts (GRBs) do originate in the collision between the accelerated baryonic matter (ABM) pulse with inhomogeneities in the interstellar medium (ISM). The initial phase of such process occurs at a Lorentz factor γ ∼ 310. The crossing of ISM inhomogeneities of sizes ∆R ∼ 10 15 cm occurs in a detector arrival time interval of ∼ 0.4 s implying an apparent superluminal behavior of ∼ 10 5 c. The long lasting debate between the validity of the external shock model vs. the internal shock model for GRBs is solved in favor of the first.To reproduce the observed light curve of GRB 991216, we have adopted, as initial conditions (Ruffini et al. 2002a) at t = 10 −21 s ∼ 0 s, a spherical shell of electron-positronphoton neutral plasma laying between the radii r 0 = 6.03 × 10 6 cm and r 1 = 2.35 × 10 8 cm: the temperature of such a plasma is 2.2 MeV, the total energy E tot = 4.83 × 10 53 erg and the total number of pairs N e + e − = 1.99 × 10 58 .Such initial conditions follow from the EMBH theory we have recently developed based on energy extraction from a black hole endowed with electromagnetic structure (EMBH)