Spitzer's Infrared Array Camera
The Infrared Array Camera (IRAC) is one of Spitzer's three science instruments,
and provides imaging capabilities at near- and mid-infrared wavelengths. It is a general-purpose camera that will be used by observers on Spitzer for a wide variety of astronomical research programs.
IRAC is a four-channel camera that provides simultaneous 5.12 x 5.12 arcmin
images at 3.6, 4.5, 5.8, and 8 microns. Each of the four detector arrays in the camera are 256 x 256 pixels in size. IRAC uses two sets of detector arrays. The two short-wavelength channels are imaged by composite detectors made from indium and antimony. The long-wavelength channels use silicon detectors that have been specially treated with arsenic. The only moving part in IRAC is the camera shutter.