THE BLANCO COSMOLOGY SURVEY: DATA ACQUISITION, PROCESSING, CALIBRATION, QUALITY DIAGNOSTICS, AND DATA RELEASE

Journal Article · Thu Sep 20 00:00:00 EDT 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/757/1/83· OSTI ID:22092227

Desai, S.; Mohr, J. J.; Semler, D. R.; Liu, J.; Bazin, G.; Zenteno, A. ^[1]; Armstrong, R. ^[2]; Bertin, E. ^[3]; Allam, S. S.; Buckley-Geer, E. J.; Lin, H.; Tucker, D. ^[4]; Barkhouse, W. A. ^[5]; Cooper, M. C. ^[6]; Hansen, S. M. ^[7]; High, F. W. ^[8]; Lin, Y. -T. ^[9]; Ngeow, C. -C. ^[10]; Rest, A. ^[11]

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1. Department of Physics, Ludwig-Maximilians-Universitaet, Scheinerstr. 1, D-81679 Muenchen (Germany)
2. Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104 (United States)
3. Institut d'Astrophysique de Paris, UMR 7095 CNRS, Universite Pierre et Marie Curie, 98 bis boulevard Arago, F-75014 Paris (France)
4. Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510 (United States)
5. Department of Physics and Astrophysics, University of North Dakota, Grand Forks, ND 58202 (United States)
6. Department of Physics and Astronomy, Frederick Reines Hall, University of California, Irvine, CA 92697 (United States)
7. University of California Observatories and Department of Astronomy, University of California, Santa Cruz, CA 95064 (United States)
8. University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States)
9. Institute for Physics and Mathematics of the Universe, University of Tokyo, 5-1-5 Kashiwa-no-ha, Kashiwa-shi, Chiba 277- 8568 (Japan)
10. Graduate Institute of Astronomy, National Central University, No. 300 Jhongda Road, Jhongli City 32001, Taiwan (China)
11. Space Telescope Science Institute, 3700 San Martin Dr., Baltimore, MD 21218 (United States)

The Blanco Cosmology Survey (BCS) is a 60 night imaging survey of {approx}80 deg{sup 2} of the southern sky located in two fields: ({alpha}, {delta}) = (5 hr, -55 Degree-Sign ) and (23 hr, -55 Degree-Sign ). The survey was carried out between 2005 and 2008 in griz bands with the Mosaic2 imager on the Blanco 4 m telescope. The primary aim of the BCS survey is to provide the data required to optically confirm and measure photometric redshifts for Sunyaev-Zel'dovich effect selected galaxy clusters from the South Pole Telescope and the Atacama Cosmology Telescope. We process and calibrate the BCS data, carrying out point-spread function-corrected model-fitting photometry for all detected objects. The median 10{sigma} galaxy (point-source) depths over the survey in griz are approximately 23.3 (23.9), 23.4 (24.0), 23.0 (23.6), and 21.3 (22.1), respectively. The astrometric accuracy relative to the USNO-B survey is {approx}45 mas. We calibrate our absolute photometry using the stellar locus in grizJ bands, and thus our absolute photometric scale derives from the Two Micron All Sky Survey, which has {approx}2% accuracy. The scatter of stars about the stellar locus indicates a systematic floor in the relative stellar photometric scatter in griz that is {approx}1.9%, {approx}2.2%, {approx}2.7%, and {approx}2.7%, respectively. A simple cut in the AstrOmatic star-galaxy classifier spread{sub m}odel produces a star sample with good spatial uniformity. We use the resulting photometric catalogs to calibrate photometric redshifts for the survey and demonstrate scatter {delta}z/(1 + z) = 0.054 with an outlier fraction {eta} < 5% to z {approx} 1. We highlight some selected science results to date and provide a full description of the released data products.

• OSTI ID: 22092227
• Journal Information: Astrophysical Journal, Vol. 757, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ACCURACY
ASTRONOMY
ASTROPHYSICS
CALIBRATION
CATALOGS
COSMOLOGY
DATA ACQUISITION
DATA ANALYSIS
GALAXIES
GALAXY CLUSTERS
IMAGE PROCESSING
PHOTOMETRY
RED SHIFT
STARS
TELESCOPES