High redshift GRBs observed by GLAST

The Gamma-ray Large Area Space Telescope (GLAST) is the next generation satellite for high energy astronomy. The flight hardware production is now complete, the sixteen towers have been integrated into the flight grid and the ACD is already placed onsite. The detector will now be integrated with the spacecraft in the next few months. GLAST will be launched in 2007 and it will cover the energy range from 10 keV to more than 300 GeV Inspiring ourself to the huge explosion observed the 4th September of 2005 by the Swift mission [1], we use the full simulation chain developed by the GLAST collaboration to simulate an high-redshift Gamma-Ray Burst, combining all the information available in literature on GRB 050904 with some assumptions, especially for the high energy emission. Our simulation takes care both of the effect of the cosmological expansion on the spectra and on the light curve, as well as the absorption of radiation by photon-photon interaction with the Extragalactic Background Light (EBL).