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

By S. Desai, R. Armstrong, J. J. Mohr, D. R. Semler, J. Liu, E. Bertin, S. Allam, W. Barkhouse, G. Bazin, Elizabeth Buckley-Geer and 10 more. 2012

187 citations recorded by the source corpus.

The Blanco Cosmology Survey (BCS) is a 60 night imaging survey of ∼80 deg2 of the southern sky located in two fields: (α, δ) = (5 hr, −55°) and (23 hr, −55°). 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 10σ 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 ∼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 ∼2% accuracy. The scatter of stars about the stellar locus indicates a systematic floor in the relative stellar photometric scatter in griz that is ∼1.9%, ∼2.2%, ∼2.7%, and ∼2.7%, respectively. A simple cut in the AstrOmatic star–galaxy classifier spread_model produces a star sample with good spatial uniformity. We use the resulting photometric catalogs to calibrate photometric redshifts for the survey and demonstrate scatter δz/(1 + z) = 0.054 with an outlier fraction η < 5% to z ∼ 1. We highlight some selected science results to date and provide a full description of the released data products.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/c4041dc9bf6d34dcd17e6aa676f9b3a8137caa11

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Citations in the corpus

BEASTS OF THE SOUTHERN WILD: DISCOVERY OF NINE ULTRA FAINT SATELLITES IN THE VICINITY OF THE MAGELLANIC CLOUDS (2015, background): “A sensible selection threshold for bright stars would be |SPREAD_MODEL| < 0.003 (Desai et al. 2012; Annunziatella et al. 2013), however for faint magnitudes this cut causes significant incompleteness in stars.”
EIGHT ULTRA-FAINT GALAXY CANDIDATES DISCOVERED IN YEAR TWO OF THE DARK ENERGY SURVEY (2015, methodology): “Photometric Calibration: Photometric calibration was performed using the stellar locus regression technique (SLR: Ivezić et al. 2004; MacDonald et al. 2004; High et al. 2009; Gilbank et al. 2011; Coupon et al. 2012; Desai et al. 2012; Kelly et al. 2014).”
TWO MICRON ALL SKY SURVEY PHOTOMETRIC REDSHIFT CATALOG: A COMPREHENSIVE THREE-DIMENSIONAL CENSUS OF THE WHOLE SKY (2013, methodology): “Whenever a sufficiently large and representative training set is available, ANNz is a highly competitive tool when compared with traditional template-fitting methods (Firth et al. 2003; Collister & Lahav 2004; Wang et al. 2009; Abdalla et al. 2011) and has been used for various data sets, including ”
The Dark Energy Survey Image Processing Pipeline (2018, methodology): “The individual SPREAD_MODEL are weighted by the inverse 7 SPREAD_MODEL is a SEXTRACTOR parameter derived from the Fisher’s linear discriminant between a model of the PSF and an extended source model convolved with the PSF (Desai et al. 2012).”
THE DARK ENERGY CAMERA (2004, background): “Note that the typical best quartile of realized image quality of the previous prime focus camera (MOSAIC II) at the Blanco telescope over a 0°.6 diameter field in the r-band filter was 0 89 with a median of 0 99 (Desai et al. 2012).”
EIGHT NEW MILKY WAY COMPANIONS DISCOVERED IN FIRST-YEAR DARK ENERGY SURVEY DATA (2015, methodology): “We refer to Sevilla et al. (2011), Desai et al. (2012), and Mohr et al. (2012) for a more detailed description of the DES singleepoch and coadd image processing.”
Dark Energy Survey Year 1 Results: The Photometric Data Set for Cosmology (2017, methodology): “The second variable, SPREAD MODEL, is derived from the Fisher’s linear discriminant between a model of the PSF and an extended source model convolved with the PSF (Desai et al. 2012; Bouy et al. 2013; Soumagnac et al. 2015).”
THE REDMAPPER GALAXY CLUSTER CATALOG FROM DES SCIENCE VERIFICATION DATA (2016, background): “Details of the DES single-epoch and coadd processing can be found in Sevilla et al. (2011) and Desai et al. (2012).”
THE DIFFERENCE IMAGING PIPELINE FOR THE TRANSIENT SEARCH IN THE DARK ENERGY SURVEY (2015, methodology): “DECam is mounted on the Blanco 4-m telescope at the Cerro Tololo Inter-American Observatory (CTIO) and the data are processed by the DES data management system (Sevilla et al. 2011; Mohr et al. 2012; Desai et al. 2012) at the National Center for Supercomputing Applications (NCSA).”
Photometric redshift analysis in the Dark Energy Survey Science Verification data (2014, methodology): “The data were processed using the same routines used by DES Data Management (DESDM) in their processing pipeline (Mohr et al. 2012; Desai et al. 2012), in particular for image detrending, astrometric calibration (SCAMP, Bertin (2006)), image remapping and coaddition (SWarp, Bertin et al. (2002)),…”
The DES Science Verification weak lensing shear catalogues (2015, methodology): “The SV data were reduced by the DES Data Management (DESDM) system (Mohr et al. 2012; Desai et al. 2012), resulting in calibrated and background-subtracted images.”
Dark Energy Survey Year 1 results: measurement of the baryon acoustic oscillation scale in the distribution of galaxies to redshift 1 (2017, methodology): “The DES Data Management (DESDM) system (Mohr et al. 2008; Sevilla et al. 2011; Desai et al. 2012) detrended, calibrated, and co-added these DES images in order to catalogue astrophysical objects.”
The Dark Energy Survey: Data Release 1 (2018, methodology): “The most common classification scheme makes use of the SExtractor SPREAD_MODEL, which compares the fit of a local PSF model to a slightly extended exponential disk model (Desai et al. 2012).”
GALAXY CLUSTERS DISCOVERED VIA THE SUNYAEV–ZEL'DOVICH EFFECT IN THE 2500-SQUARE-DEGREE SPT-SZ SURVEY (2014, methodology): “Initially, clusters were confirmed using preexisting imaging from the Blanco Cosmology Survey (BCS; Menanteau et al. 2010b; Desai et al. 2012; Bleem et al. 2015, see Section 4.3) as well as targeted imaging on the Blanco/ MOSAIC-II49, and Magellan/IMACS imagers (Dressler et al. 2006) (see High et…”
Star-galaxy Classification Using Deep Convolutional Neural Networks (2016, methodology): “Currently ongoing and forthcoming large-scale photometric surveys, such as the Dark Energy Survey (DES) and the Large Synoptic Survey Telescope (LSST), aim to collect photometric data for hundreds of millions to billions of stars and galaxies.”