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Paper: The Lost Flux Method: A New Algorithm for Improving the Precision of Space-Based Near-Infrared Stellar Photometry with Lossy Detectors
Volume: 376, Astronomical Data Analysis Software and Systems XVI
Page: 405
Authors: Mighell, K.J.
Abstract: Current infrared detector technology can produce imagers with non-uniform intra-pixel response functions. Cameras based on such detectors can have large systematic errors in the measurement of the total stellar flux. Although this problem can be mitigated by oversampling the stellar image, many near-infrared cameras are undersampled in order to achieve a large field of view. The combination of undersampling stellar images with non-uniform detectors is currently diminishing some of the potential science return of some infrared imagers onboard the Hubble Space Telescope and the Spitzer Space Telescope. Although the recorded flux and position of point sources is corrupted by using detectors with non-uniform intrapixel response functions, it is still possible to achieve excellent stellar photometry and astrometry—if the image formation process inside the detector is accurately modeled. A new analysis algorithm called the Lost Flux Method is described and used to demonstrate how the precision of stellar photometry from an existing space-based near-infrared camera with a lossy detector can be significantly improved. Multiple observations of a single bright isolated star obtained with Channel 1 of the Spitzer Space Telescope Infrared Array Camera (IRAC) instrument are analyzed with the Lost Flux Method which yields an improvement in photometric precision of more than 100% over the best results obtained with aperture photometry.
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