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MIPS : Instrument Description |
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The Multiband Imaging Photometer for Spitzer (MIPS) provides the Spitzer
Space Telescope with capabilities for imaging and photometry in broad
spectral bands centered nominally at 24, 70, and 160 microns, and for
low-resolution spectroscopy between 55 and 95 microns. The instrument
contains 3 separate detector arrays each of which resolves the telescope
Airy disk with pixels of size lambda / 2D or smaller. All three arrays
view the sky simultaneously; multiband imaging at a given point is
provided via telescope motions. The 24 micron camera provides roughly a
5 square field of view (FOV). The 70 micron camera was designed to have a
5 square FOV, but a cabling problem compromised the outputs of half the
array; the remaining side ("side A") provides a FOV that is roughly 2.5 by
5. The 160 micron array projects to the equivalent of a 0.5 by 5 FOV and
fills in a 2 by 5 image by multiple exposures. The 70 micron array also
has a narrow FOV/higher magnification mode, and is additionally used in a
spectroscopic mode. The MIPS cryogenic scan mirror mechanism (CSMM) is
integral to all observational operations, allowing selection of different
optical trains, image motion compensation during scanned imaging, and one
dimensional image dithering. A brief, high-level summary of MIPS for
astronomers appears in the ApJS Spitzer Special Issue, specifically the
paper by Rieke et al. (2004, ApJS,
154, 25) entitled "The Multiband Imaging Spectrometer for Spitzer."
There are four basic operating modes and associated Astronomical Observation Templates (AOTs) for MIPS. The Scan Mapping AOT is used to image large areas of the sky in one or more bands nearly simultaneously. The Photometry and Super Resolution AOT is used to image sources smaller than about 2 diameter, including point sources. The Spectral Energy Distribution (SED) AOT is used to obtain low-resolution (R~20) spectra in the 70 micron band. The Total Power (TP) AOT is used to measure the absolute brightness of highly extended emission, e.g., zodiacal light. Each AOT includes a number of options, providing good flexibility for designing observations. MIPS is advancing our knowledge of the far-IR universe by providing the ability to make measurements of unprecedented sensitivity and spatial resolution. Although the design of MIPS was optimized around the four defining science themes for Spitzer, its capabilities were also established from a very general perspective and it is well suited to a broad variety of investigations.
(a)Note that full spectral coverage is limited to only 32x12 because of the dead 70 micron readout and the noisy side B. (b) Slit width is 2 pixels, slit length is 16 pixels; note that full spectral coverage is only obtained over a 2.0 arcmin length of the slit because of the dead 70 micron readout. (c) Because of a bad readout at one end of the slit, the spectral coverage for 4 columns of the array is reduced to about 65-95 microns. (d) Includes scan motion required to sample PSF fully. Single frame FOV is 5.3x0.5 arcminutes.
OpticsThe telescope Point Spread Function (PSF) size (~lambda/D) is 6", 18", and 40" full width at half maximum, at 24, 70 and 160 microns respectively.
For more information, see the MIPS chapter of the SOM
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help@spitzer.caltech.edu http://ssc.spitzer.caltech.edu/mips/descrip.html
