ISGRI: the INTEGRAL Soft Gamma-Ray Imager

F. Lebrun (1) , J.-P. Leray (1) , P. Lavocat (1) , J. Crétolle (1) , M. Arquès (2) , C. Blondel (1) , C. Bonnin (1) , A. Bouère (1) , C. Cara (1) , T. Chaleil (3) , F. Daly (1) , F. Desages (4) , H. Dzitko (1) , B. Horeau (1) , Philippe Laurent (1) , O. Limousin (1) , F. Mathy (2) , V. Mauguen (1) , F. Meignier (1) , F. Molinié (3) , E. Poindron (1) , M. Rouger (4) , A. Sauvageon (1) , T. Tourette (1)

1 DAP - Département d'Astrophysique (ex SAP)
2 CEA-LETI - Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information
3 DIS - Département d'Ingénierie des Systèmes (ex SIS)
4 DEDIP - Département d'Electronique, des Détecteurs et d'Informatique pour la Physique (ex SEDI)

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.

Mots clés: IBIS.

Mots clés: Space Telescope; Cadmium Telluride Detectors; Gamma-ray Astronomy; Calibration; INTEGRAL; IBIS

Domaines: Cosmologie et astrophysique extra-galactique [astro-ph.CO]

F. Lebrun, J.-P. Leray, P. Lavocat, J. Crétolle, M. Arquès, et al.. ISGRI: the INTEGRAL Soft Gamma-Ray Imager. 2003. ⟨hal-00000723⟩