An upscattering spectral formation model for the prompt emission of Gamma Ray Bursts
Wednesday 13 June 2012
to 14:00 at
Ruben Farinelli (Ferrara University)
We propose a model for the spectral formation of Gamma Ray Burst (GRB) prompt
emission. We suggest that the Band function spectrum is a result of two upscattering processes. The first one is due to Comptonization of a blackbody-like seed photon spectrum of a few keV temperature or less off a hot electron population moving outward with subrelativistic bulk velocity.
In the second phase, this thermal plus bulk Comptonization spectrum is phenomenologically convolved with an upscattering Green function and thus gives rise to the extended high-energy powerlaw component above the sub-MeV peak energy. We discuss the implementation of our model in the XSPEC package and show some results applied to a sample of GRBs. Additionally, we show how this scenario could explain the Amati relation in which the peak energy of the emergent GRB spectrum correlates with the fluence.