Overview about first results from the Gamma-Ray Astronomy Mission INTEGRAL

摘要

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 15 keV to 10 MeV, and are mainly devoted to high resolution spectroscopy (ΔE ～ 2,5 keV at 1 MeV) and fine source imaging (Δv ～ 12 arcmin), respectively. The 4 tons heavy payload was brought into an excentric orbit of 153.000 km apogee and 9.000 km perigee on October 17, 2002 by a Russian Proton rocket. After a successful performance and verification phase, the observational program started in late December 2002 by executing open-time proposals and guaranteed core-time observations. The observations concentrated mainly towards the galactic plane, and especially the inner Galaxy. Highlights from the first 18 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. Whereas line measurements generally require deep exposures of several million seconds (1 month and more), results on compact objects can be obtained much easier - in most cases they require exposures of only one or a few days.