High resolution spectroscopy of the X-ray emission of GRBs by IMXS-BOSS on the ISS

The IMXS (Interstellar and intergalactic Medium X-ray Survey) - BOSS (gamma-ray Burst Observatory and Spectroscopy Survey) is an experiment proposed to fly on the ISS (International Space Station), in order to perform an all-sky survey to study the diffuse X-ray emission and to measure the spectra of Gamma-Ray Bursts (GRB) with high energy resolution in the 0.1-10 keV energy range, In a 3 years lifetime mission, the experiment will detect about 20 to 40 GRBs. In several events, we can perform high resolution spectroscopy of the iron emission lines and absorption edges. Such components have been observed by BeppoSAX and Chandra. The measurements of these features would provide a direct diagnostic of the physical and kinematical state of the medium surrounding a GRB, Further-more, they would supply information about the origin of the progenitors of the GRBs (probably a supernova explosion of massive stars) and their site formation (possibly a star-forming region).