The Blanco Cosmology Survey: Data Acquisition, Processing, Calibration, Quality Diagnostics and Data Release

Abstract

The Blanco Cosmology Survey (BCS) is a 60 night imaging survey of $\sim$80 deg${}^2$ of the southern sky located in two fields: ($\alpha$,$\delta$)= (5 hr, $-55^{\circ }$) and (23 hr, $-55^{\circ }$). The survey was carried out between 2005 and 2008 in $griz$ bands with the Mosaic2 imager on the Blanco 4m 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 PSF 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 $\sim 45$ milli-arcsec. We calibrate our absolute photometry using the stellar locus in $grizJ$ bands, and thus our absolute photometric scale derives from 2MASS which has $\sim 2$% accuracy. The scatter of stars about the stellar locus indicates a systematics floor in the relative stellar photometric scatter in $griz$ that is $\sim$1.9%, $\sim$2.2%, $\sim$2.7% and$\sim$2.7%, respectively. A simple cut in the AstrOmatic star-galaxy classifier {\tt 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 $\delta z/(1+z)=0.054$ with an outlier fraction $\eta <5$% to $z\sim 1$. We highlight some selected science results to date and provide a full description of the released data products.

23 pages, 23 figures . Response to referee comments. Paper accepted for publication. BCS catalogs and images available for download from http://www.usm.uni-muenchen.de/BCS

References in corpus (16)

• The imprints of primordial non-gaussianities on large-scale structure: scale dependent bias and abundance of virialized objects
• The All-wavelength Extended Groth Strip International Survey (AEGIS) Data Sets
• Stellar SEDs from 0.3-2.5 Microns: Tracing the Stellar Locus and Searching for Color Outliers in SDSS and 2MASS
• SDSS Standard Star Catalog for Stripe 82: the Dawn of Industrial 1% Optical Photometry
• High resolution CMB power spectrum from the complete ACBAR data set
• Galaxy clusters discovered with a Sunyaev-Zel'dovich effect survey
• The Galaxy Content of SDSS Clusters and Groups
• A Galaxy Photometric Redshift Catalog for the Sloan Digital Sky Survey Data Release 6
• Cosmological Constraints from the Red-Sequence Cluster Survey
• The Atacama Cosmology Telescope: Physical Properties and Purity of a Galaxy Cluster Sample Selected via the Sunyaev-Zel'dovich Effect
• MegaZ-LRG: A photometric redshift catalogue of one million SDSS Luminous Red Galaxies
• A Measurement of the Correlation of Galaxy Surveys with CMB Lensing Convergence Maps from the South Pole Telescope
• The Northern Sky Optical Cluster Survey III: A Cluster Catalog Covering Pi Steradians
• The Dark Energy Survey Data Management System
• Physical Properties of Four SZE-Selected Galaxy Clusters in the Southern Cosmology Survey
• Cyber-infrastructure to Support Science and Data Management for the Dark Energy Survey

Cited by in corpus (50)

• Galaxy Clusters Discovered via the Sunyaev-Zel'dovich Effect in the 2500-square-degree SPT-SZ survey
• Beasts of the Southern Wild: Discovery of nine Ultra Faint satellites in the vicinity of the Magellanic Clouds
• The unWISE Catalog: Two Billion Infrared Sources from Five Years of WISE Imaging
• Star-galaxy Classification Using Deep Convolutional Neural Networks
• Photometric redshift analysis in the Dark Energy Survey Science Verification data
• Redshifts, Sample Purity, and BCG Positions for the Galaxy Cluster Catalog from the first 720 Square Degrees of the South Pole Telescope Survey
• Convolution kernels for multi-wavelength imaging
• Characterization and correction of charge-induced pixel shifts in DECam
• Mass and galaxy distributions of four massive galaxy clusters from Dark Energy Survey Science Verification data
• The Blanco Cosmology Survey: An Optically-Selected Galaxy Cluster Catalog and a Public Release of Optical Data Products
• DES13S2cmm: The First Superluminous Supernova from the Dark Energy Survey
• Portrait of a Dark Horse: a Photometric and Spectroscopic Study of the Ultra-faint Milky Way Satellite Pegasus III
• The LMC geometry and outer stellar populations from early DES data
• Modelling the Transfer Function for the Dark Energy Survey
• A Search for Kilonovae in the Dark Energy Survey
• Instrumental response model and detrending for the Dark Energy Camera
• Testing Isotropy in the Local Universe
• Combining Dark Energy Survey Science Verification Data with Near Infrared Data from the ESO VISTA Hemisphere Survey
• A Neural Network Gravitational Arc Finder based on the Mediatrix filamentation Method
• The XXL survey XV: Evidence for dry merger driven BCG growth in XXL-100-GC X-ray clusters
• Stellar metallicities from SkyMapper photometry I: A study of the Tucana II ultra-faint dwarf galaxy
• Optical Confirmation and Redshift Estimation of the Planck Cluster Candidates overlapping the Pan-STARRS Survey
• Candidate Clusters of Galaxies at $z>1.3$ Identified in the Spitzer SPT Deep Field Survey
• A Study of Quasar Selection in the Dark Energy Survey Supernova fields
• Environmental dependence of the galaxy stellar mass function in the Dark Energy Survey Science Verification Data
• Effect of training characteristics on object classification: an application using Boosted Decision Trees
• Structured star formation in the Magellanic inter-Cloud region
• The stellar mass - size relation for cluster galaxies at z=1 with high angular resolution from the Gemini/GeMS multi-conjugate adaptive optics system
• The XXL Survey: XXXVI. Evolution and black hole feedback of high-excitation and low-excitation radio galaxies in XXL-S
• Identification of RR Lyrae stars in multiband, sparsely-sampled data from the Dark Energy Survey using template fitting and Random Forest classification
• The OTELO survey. I. Description, data reduction, and multi-wavelength catalogue
• Searching for Extragalactic Sources in the VISTA Variables in the Vía Láctea Survey
• The relation between globular cluster systems and supermassive black holes in spiral galaxies. The case study of NGC 4258
• Preparing for advanced LIGO: A Star-Galaxy Separation Catalog for the Palomar Transient Factory
• Analysis of Sunyaev-Zel'dovich Effect Mass-Observable Relations using South Pole Telescope Observations of an X-ray Selected Sample of Low Mass Galaxy Clusters and Groups
• A panoramic view of the Local Group dwarf galaxy NGC 6822
• Tracing the Assembly History of NGC 1395 through its Globular Cluster System
• Morphological Star-Galaxy Separation
• The Clusters Hiding in Plain Sight (CHiPS) survey: Complete sample of extreme BCG clusters
• UV-Luminous, Star-Forming Hosts of z~2 Reddened Quasars in the Dark Energy Survey
• Radio-Optical Galaxy Shape Correlations in the COSMOS Field
• CosmoDM and its application to Pan-STARRS data
• ShapePipe: A modular weak-lensing processing and analysis pipeline
• Spectroscopy of NGC 4258 globular cluster candidates: membership confirmation and kinematics
• A model-independent test of the evolution of gas depletion factor for SPT-SZ and Planck ESZ clusters
• Constraints on Self-Interacting dark matter from relaxed galaxy groups
• A pilot search for MeV gamma-ray emission from five galaxy clusters using archival COMPTEL data
• Clash of Titans: The Impact of Cluster Mergers in the Galaxy Cluster Red Sequence
• Cosmic Ray Rejection with Attention Augmented Deep Learning
• A test of galaxy cluster fundamental plane for the X-COP sample