A&A 411, L141-L148 (2003)
ISGRI: The INTEGRAL Soft Gamma-Ray ImagerF. Lebrun1, J. P. Leray1, P. Lavocat1, J. Crétolle1, M. Arquès2, C. Blondel1, C. Bonnin1, A. Bouère1, C. Cara1, T. Chaleil3, F. Daly1, F. Desages4, H. Dzitko1, B. Horeau1, P. Laurent1, O. Limousin1, F. Mathy2, V. Mauguen1, F. Meignier1, F. Molinié3, E. Poindron1, M. Rouger4, A. Sauvageon1 and T. Tourrette1
1 CEA-Saclay, DSM/DAPNIA/Service d'Astrophysique, 91191 Gif-sur-Yvette Cedex, France,
2 CEA-Grenoble, LETI, 17 rue des Martyrs, Grenoble Cedex 9, France,
3 CEA-Saclay, DSM/DAPNIA/SIS, 91191 Gif-sur-Yvette Cedex, France,
4 CEA-Saclay, DSM/DAPNIA/SEDI, 91191 Gif-sur-Yvette Cedex, France
(Received 17 July 2003 / Accepted 4 September 2003)
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 10 6 s observation.
Key words: space telescope -- cadmium telluride detectors -- gamma-ray astronomy -- calibration -- INTEGRAL -- IBIS.
Offprint request: F. Lebrun, email@example.com
© ESO 2003