Influence of nonuniform charge-coupled device pixel response on aperture photometry
Abstract
The extensive use of charge-coupled devices (CCDs) in astronomical
imaging and spectroscopic applications has resulted in techniques
being developed to correct for sensitivity variations attributable to
the focal plane array detector. One normally overlooked effect is that
these sensitivity variations also include intrapixel spatial effects that can
influence measurements made with CCDs in certain circumstances. We
demonstrate the influence of CCD pixel response nonuniformity on photometric
measurements. An investigation is presented of how the relation
between pixel size and the image size affects the photometric accuracy.
Results are presented for a front-illuminated CCD array using an experimentally
measured pixel sensitivity functions.