First Results of the Gamma-Ray Mission INTEGRAL

INTEGRAL is an ESA space mission to study the sky at hard X-ray and soft gamma-ray energies. Its two main instruments SPI and IBIS cover the energy range 20 keV to 10 MeV, and are mainly devoted to high resolution spectroscopy and fine source imaging, respectively. The observational program started in late December 2002 and concentrated mainly towards the galactic plane, and especially the inner Galaxy. Highlights from the first 15 months of the mission are results on nucleosynthesis and solar flare gamma-ray lines, on a survey of hard X-ray binary sources and their identification, on the origin of the "diffuse" galactic ridge emission, and on gamma-ray bursts.