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H. Thomas Diehl, Douglas Tucker; Fermi National Accelerator Laboratory


dark energy, galaxies, particles, gravity


Astrophysics and Astronomy | External Galaxies | Instrumentation


Astronomical images taken from a telescope must go through “astronomical image processing” to remove instrumental signatures. The Dark Energy Survey (DES), which will start operations in 2012, will use a 570 megapixel Dark Energy Camera (DECam) to study the mystery of the acceleration of the expanding universe. The DECam will use DES filters and 74 of a new type of astronomical Charge Coupled Device (CCD) that is particularly efficient in detecting near-infrared light. Together, the DES filters and DECam CCDs are optimized for the measurement of redshifts of distant galaxies. In preparation for the DES, data were collected from the 1 meter telescope at Cerro Tololo Inter-American Observatory (CTIO) in Chile, using a DES filter set and a DECam CCD as a test set for the initial analysis of data. Here, these CTIO-1m data were used to determine the relationship between the apparent measured brightness of stars of known brightness (standard stars) and the amount of atmosphere the telescope looks through (angular distance from the zenith or “airmass”). This relationship was tested against the results from another telescope using similar filters. Finally, this relationship was used to calibrate the brightness of stars of unknown brightness that were also observed in the CTIO 1m data set.


Copyright permission granted by The Journal of Experimental Secondary Science



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