Análisis temporal y espectral de la estructura interna de las ráfagas de rayos gamma con z cercano a 1

Abstract

We investigated the internal structure of a sample of 5 long GRBs detected by Swift satellite with z close to 1. We studied the high resolved temporal and spectral structure of the selected GRBs. First, we determined the spectral lag applying an exponential model (Norris model, 2005). We fitted the pulses with Norris model in four different energy channels according to the sensitivity of the BAT detector (15-150 KeV) and calculated different lags using 4 chosen bands. We concluded that high energy photons arrived before low energy photons. Moreover, we performed spectral analysis in regions of 1 second width; the temporal evolution of spectral parameters were determined. In this analysis, we used two spectral models: power law and cutoff power law, thus we determined that the contribution of the synchrotron radiation inside the burst is important to the 45% of the GRBs’ regions. Moreover, we found that the synchrotron radiation is important to 80% of pulses. Finally, we investigated possible correlation between the spectral lag and spectral parameters associated to each pulse such as photon index and luminosity. Additionaly, we demostrated the anticorrelation between lag-luminosity. Nevertheless, we did not find a correlation between spectral lag and photon index.