Spitzer Documentation & Tools
MIPS Instrument Handbook

2.2.2        Field of View

All three arrays simultaneously view non-overlapping fields on the sky. The 24 m array has a ~5 square field of view; roughly 8 away is the 70 m array. The 70 m array suffers from thermally-activated high resistance in a cable connection that is external to the instrument, but feeds it. This has resulted in significantly increased noise on side B of the array, rendering that side essentially unusable. Also, one readout on side A (located in the lower right corner in data oriented as observers receive it, next to side B) is inoperative; the resulting shape (roughly 2.5x5) can be seen in 70 m bad pixel mask (see section 6.5).

 

Basic parameters of interest for MIPS are summarized in Table 2.1.

Table 2.1: MIPS principal optical parameters.

Band Mode Array Format Pointed FOV (arcmin) Pixel Size (arcsec)  (m) F/#  
24m Imaging 128x128 5.4x5.4 2.49x2.60 23.7 7.4 4.7m
70m Wide FOV 32x32 5.2x2.6 9.85x10.06 71 18.7 19 m
70m Narrow FOV/ Super Res 32x32 2.7x1.35 5.24x5.33 71 37.4 19 m
70m SED 32x241 2.7x0.342 9.8 55-953 18.7 1.7 m/px
160m Imaging 2x20 5.3x2.14 15.96x18.04 156 46 35 m

1 Note that full spectral coverage is limited to only 32x12 because of the dead 70 m readout and the noisy side B.

2 Slit width is 2 pixels, slit length is 16 pixels; note that full spectral coverage is only obtained over a 2.0 length of the slit because of the dead 70 m readout.

3 Because of a bad readout at one end of the slit, the spectral coverage for 4 columns of the array is reduced to about 65-106 m.

4 Includes scan motion required to sample PSF fully. Single frame FOV is 5.3x0.5 arcminutes.

 

In a single pointing,the 160 m array views two 5.3 by 16 strips separated by a 16 wide blank strip giving a 5.3x0.75 unfilled FOV. The central blank strip of the 160 m array is filled by taking images at interleaved scan positions. One block of 5 contiguous pixels in the 160 m array exhibits anomalous behavior attributable to a thermally-activated short in cabling external to MIPS but well inside the Cryogenic Telescope Assembly. In data oriented as observers receive it, this block is located in the bottom row; it is the third group of 5 pixels in from the left. The ''bite'' taken out of the array is visible in the 160 m bad pixel mask (see section 6.5). These pixels are not quite square at 16x18. Occasionally for brevity, we refer to these pixels as 16 square with the knowledge that they are slightly rectangular.