IRAC High Precision Photometry

Due to the under-sampled nature of the PSF, the warm IRAC arrays show variations of as much as 8% in sensitivity as the center of the PSF moves across a pixel due to normal spacecraft motions. These intra-pixel gain variations are the largest source of correlated noise in IRAC photometry. Many data reduction techniques rely on the science data themselves to remove the gain variations as a function of position.  The SSC has generated a high-resolution gain map from standard star data, which can be used as an alternative when reducing data.