2015/04/23 by Michael Baumer, Aaron Roodman, Baumer, Michael +1
Physics and Astronomy · #FOS: Physical sciences #Instrumentation and Methods for Astrophysics (astro-ph.IM) #astro-ph.IM
paper · pdf · doi:10.48550/arxiv.1504.06088
8 pages, 6 figures, Submitted to the proceedings of "Precision Astronomy with Fully Depleted CCDs", held at Brookhaven National Laboratory, December 4-5, 2014
arxiv created 2015/04/23 · arxiv updated 2015/04/24
The ambitious science goals of the Large Synoptic Survey Telescope (LSST) have motivated a search for new and unexpected sources of systematic error in the LSST camera. Flat-field images are a rich source of data on sensor anomalies, although such effects are typically dwarfed by shot noise in a single flat field. After combining many (∼ 500) such images into `ultraflats' to reduce the impact of shot noise, we perform photon transfer analysis on a pixel-by-pixel basis and observe no spatial structure in pixel linearity or gain at light levels of 100 ke- and below. At 125 ke-, a columnar structure is observed in the gain map--we attribute this to a flux-dependent charge transfer inefficiency. We also probe small-scale variations in effective pixel size by analyzing pixel-neighbor correlations in ultraflat images, where we observe clear evidence of intrinsic variation in effective pixel size in an LSST prototype sensor near the ∼ .3% level.