GRB 090423 at redshift 8.1: A theoretical interpretation

GRB 090423 is the farthest gamma ray burst ever observed, with a redshift of about 8.1. We present within the fireshell scenario a complete analysis of this GRB.We model the prompt emission and the first rapid flux decay of the afterglow emission as being to the canonical emission of the interaction in the interval 0 ≤ t ≤ 440 s by using accelerated baryonic matter with the circumburst medium. After the data reduction of the Swift data in the BAT (15 - 150 keV) and XRT (0.2 - 10 keV) energy bands, we interpret the light curves and the spectral distribution in the context of the fireshell scenario. We also confirm in this source the existence of a second component, a plateau phase, as being responsible for the late emission in the X-ray light curve. This extra component originates from the fact that the ejecta have a range of the bulk Lorentz I' factor, which starts to interact each other ejecta at the start of the plateau phase.