Spitzer Space Telescope - Instruments

Instruments

Spitzer carries three instruments on-board:

• IRAC (Infrared Array Camera), an infrared camera which operates simultaneously on four wavelengths (3.6 µm, 4.5 µm, 5.8 µm and 8 µm). Each module uses a 256×256-pixel detector—the short wavelength pair use indium antimonide technology, the long wavelength pair use arsenic-doped silicon impurity band conduction technology. The two shorter wavelength bands (3.6 µm & 4.5 µm) for this instrument remain productive after LHe depletion in the spring of 2009, at the telescope equilibrium temperature of around 30 K, so IRAC continues to operate as the "Spitzer Warm Mission". The principal investigator is Giovanni Fazio of Harvard University; the flight hardware was built by Johns Hopkins University Applied Physics Laboratory.

• IRS (Infrared Spectrograph), an infrared spectrometer with four sub-modules which operate at the wavelengths 5.3–14 µm (low resolution), 10–19.5 µm (high resolution), 14–40 µm (low resolution), and 19–37 µm (high resolution). Each module uses a 128×128-pixel detector—the short wavelength pair use arsenic-doped silicon blocked impurity band technology, the long wavelength pair use antimony-doped silicon blocked impurity band technology. The principal investigator is James R. Houck of Cornell University; the flight hardware was built by Ball Aerospace.

• MIPS (Multiband Imaging Photometer for Spitzer), three detector arrays in the far infrared (128 × 128 pixels at 24 µm, 32 × 32 pixels at 70 µm, 2 × 20 pixels at 160 µm). The 24 µm detector is identical to one of the IRS short wavelength modules. The 70 µm detector uses gallium-doped germanium technology, and the 160 µm detector also uses gallium-doped germanium, but with mechanical stress added to each pixel to lower the bandgap and extend sensitivity to this long wavelength. The principal investigator is George H. Rieke of the University of Arizona; the flight hardware was built by Ball Aerospace.

As an example of data from the different instruments, the nebula Henize 206 was imaged in 2004, allowing comparison of images from each device.