The INTErnational Gamma-Ray Astrophysics Laboratory
is an astronomical satellite for observing the gamma-ray sky.
INTEGRAL is a truly international mission with the participation
of ESA member states, the United States, Russia, Czech Republic and Poland.
It was launched on October, 17th, 2002 and is planned to keep obtaining
high-quality data from most violent astronomical objects at least until 2014.
The two main instruments of the observatory are:
- The Spectrometer on INTEGRAL (SPI) which measures the energy of gamma-rays
with an extraordinary accuracy over an energy range between 20 keV and 8 MeV.
This is achieved thanks to an array of 19 hexagonal high-purity germanium detectors.
- The Imager on Board the INTEGRAL Satellite (IBIS) which has been optimised for fine
imaging and precise detection of radiation sources. The detector uses two parallel planes of pixels
located one on top of the other, thus allowing detection of both low and
high energy photons. The top layer, ISGRI, is made of 16,384 CdTe (Cadmium-Tellure)
pixels and the bottom layer, PICsIT, is made of 4096 CsI (Cesium-Iode) pixels.
IBIS achieves an angular resolution of 12 arcmin over an energy range between 15 keV and 1 MeV.