ISGRI: The INTEGRAL Soft Gamma-Ray Imager
Laurent, P.; Dzitko, H.; Lebrun, F.; Blondel, C.; Sauvageon, A.; Limousin, O.; Horeau, B.; Leray, J. P.; Lavocat, P.; Crétolle, J.; Arquès, M.; Bonnin, C.; Bouère, A.; Cara, C.; Chaleil, T.; Daly, F.; Desages, F.; Mathy, F.; Mauguen, V.; Meignier, F.; Molinié, F.; Poindron, E.; Rouger, M.; Tourrette, T.
France
Abstract
For the first time in the history of high energy astronomy, a large CdTe gamma-ray camera is operating in space. ISGRI is the low-energy camera of the IBIS telescope on board the INTEGRAL satellite. This paper details its design and its in-flight behavior and performances. Having a sensitive area of 2621 cm2 with a spatial resolution of 4.6 mm, a low threshold around 12 keV and an energy resolution of ~ 8% at 60 keV, ISGRI shows absolutely no signs of degradation after 9 months in orbit. All aspects of its in-flight behavior and scientific performance are fully nominal, and in particular the observed background level confirms the expected sensitivity of 1 milliCrab for a 106 s observation.
Based on observations with INTEGRAL, an ESA project with instruments and science data centre funded by ESA member states (especially the PI countries: Denmark, France, Germany, Italy, Switzerland, Spain), Czech Republic and Poland, and with the participation of Russia and the USA.