Infrared Array Camera
[[File:Spitzer IRAC View of the Trifid Nebula.jpg|thumb|Here is a four-band IRAC image. Because its near-to mid infrared, the wavelengths the cameera see's are mapped to the visible colors that humans see for an image (See [[False color). In this image of the Trifid nebula 3.6 microns (blue), 4.5 microns (green), 5.8 microns (orange) and 8.0 microns (red).]] Infrared Array Camera (IRAC) is an instrument on the Spitzer Space Telescope.[1] It is an electronic infrared camera for astronomical imaging, and it can detect from the near to mid infrared.[2] The sensor can detect light with a wavelength of 3 microns to 8 microns when chilled.[3] The detectors have a resolution of 256 by 256 pixels, and there is four detectors that view four bands at the same time.[4][5]
Light bands IRAC can observe in wavelength microns:[6][7]
- 3.6
- 4.5
- 5.8
- 8.0
It can view all four wavelength bands at the same time, whats called a broad-band image.[8] The 3.6 and 4.5 micron bands use InSb (Indium antimonide) detectors, and the 5.8 and 8 micron bands use Si:As (Silicon doped with Arsenic) detecors[9][10][11] The 3.6 and 4.5 wavelengths band could be operated when the coolant runs out and the telescope warms up, whereas the 5.8 and 8 microns wavelength bands operated only when the coolant chilled the telescope to even colder temperatures.[12] The IRAC instrument is contained in the Spitzer Multiple Instrument Chamber with several other pieces of technology, including the other focal plane instruments.[13] In the MIC is the Infrared Array Camera, Infrared Spectrograph, and Multiband Imaging Photometer as well as the pointing calibration reference sensor.[14] The MIC is attached to the cryostat and it is intended to keep the science instruments cold, including IRAC, but also to keep stray light.[15]