ISGRI: The INTEGRAL soft gamma-ray imager
/ Authors
F. Lebrun, J. Leray, P. Lavocat, J. Cretolle, M. Arques, C. Blondel, C. Bonnin, A. Bouère, C. Cara, T. Chaleil
and 14 more authors
F. Daly, F. Desages, H. Dzitko, B. Horeau, Philippe Laurent, O. Limousin, F. Mathy, V. Mauguen, F. Meignier, F. Molinié, E. Poindron, M. Rouger, A. Sauvageon, T. Tourette
/ Abstract
For the first time in the history of high energyastronomy, 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 itsin-flight behavior and performances. Having a sensitive area of 2621 cm$^2$ with a spatial resolution of 4.6 mm, a low threshold around 12 keV and an energy resolution of $\sim$ 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 observedbackground level confirms the expected sensitivity of 1 milliCrab for a 10$^6$s observation.
Journal: Astronomy and Astrophysics