Spitzer Documentation & Tools
Peakup Imaging Darks

Dark subtraction removes zodiacal emission in addition to detector dark current. Users whose science interests require accurate zodiacal light measurements will need to add this back.

Dark cubes for each exposure time (6, 14, 30s) were run through the slope_finder module to produce a 2D image. In the normal science pipeline, the combination of dark subtraction and the darkdrift module removes jailbar artifacts from the data. See the IRS Instrument Handbook for details on the pipeline.

Users will not wish to reintroduce such artifacts when adding back the dark cutouts provided here, so we run the 2D dark image through darkdrift to remove jailbars from the dark image. The 2D dark image was then flat fielded, blue and red image cutouts were made, and the image cutouts were multiplied by the appropriate zeropoint to convert from e-/s to MJy/sr. The header keywords BUNIT and FLUXCONV were edited to match.

Note - the 6s dark cutouts have residual jailbars (red) and a flux gradient along the y axis (blue).

Users may download the blue and red peakup dark below:

# IMAGE NPIX MEAN MIDPT STDDEV MIN MAX Comment
b0_r6_bdark.fits 2296 13.27 14.45 3.5 0. 16.7 6 second blue dark
b0_r6_rdark.fits 2296 13.94 15.75 4.349 0. 16.666 second red dark
b0_r14_bdark.fits 2296 12.26 14.03 4.106 0. 14.6114 second blue dark
b0_r14_rdark.fits 2296 14. 15.52 4.163 0. 16.514 second red dark
b0_r30_bdark.fits 2296 12.12 13.71 3.85 0. 14.3730 second blue dark
b0_r30_rdark.fits 2296 13.88 15.32 3.999 0. 16.630 second red dark