Author: Ruben Salvaterra
Abstract: The Swift mission has represented a breakthrough for the detection of GRBs from the local Universe up to the highest redshifts. However, statistical studies of their rest-frame properties and their evolution with cosmic time are still hampered by the fact that most of the observed GRBs lack of redshift measurements. I will present a complete sub-sample of 58 Swift bright long GRBs.The sample was selected considering bursts with favorable observing conditions for ground-based follow-up observations and with the 1-second peak flux above a flux threshold of 2.6 ph/cm2/s in the 15-150 keV energy band. This sample has a redshift completeness level higher than 90%. In the light of this complete sample, I will discuss the properties of long GRBs and their evolution with cosmic times, focusing in particular on the GRB luminosity function, the prompt emission spectral-energy correlations and the nature of dark bursts.