1.ICRANet,Pescara,Italy;2.ICRA and University of Rome “Sapienza”,Physics Department,Rome,Italy;3.School of Astronomy,Institute for Research in Fundamental Sciences (IPM),Tehran,Iran
Abstract:
In this work we study a role of baryon load and interstellarmediumdensity to explain the nature of peaks in the ultra-relativistic prompt emission (UPE) phase of Gamma-ray Bursts (GRBs). We study the behavior of their Γ Lorenz factor fromthe moment of transparency all the way up to interstellarmedium. We finally study the characteristic of equitemporal surfaces in the UPE phase.