GRB4 - Models for GRBs |
Speaker |
Patricelli, Barbara |
Talk Title |
A new spectral energy distribution of photons in the Fireshell Model of GRBs: preliminary results |
Abstract |
The behaviour of the N(E) spectrum of the prompt emission of Gamma Ray Bursts (GRBs) is usually described as a ``power-law''. The Fireshell model postulates that the emission process is thermal in the comoving frame of the fireshell and the effective spectrum has a non thermal-shape, being the convolution of various thermal spectra having different temperatures over the Equitemporal Surfaces (EQTS) and observational time. This assumption has been successfully tested on many GRBs; nevertheless, it can be considered just a first approximation. \\ We investigate the possibility of reproducing the observed spectra and light curves of GRBs within the Fireshell Model by assuming a phenomenologically modified black body spectrum for photons changing the energy slope of the spectrum and introducing the index $\alpha$. We obtain all the equations involved in the determination of the GRB luminosity, taking into account the convolution over the EQTS. We test the new model on several GRBs, obtaining in all cases $\alpha \sim -1.8$. We present as specific examples the cases of GRB 080319 and GRB 050904. |
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