Tests of the Las Campanas Distant Cluster Survey from Confirmation Observations for the ESO Distant Cluster Survey

Abstract

The ESO Distant Cluster Survey (EDisCS) is a photometric and spectroscopic study of the galaxy cluster population at two epochs, z~0.5 and z~0.8, drawn from the Las Campanas Distant Cluster Survey (LCDCS). We report results from the initial candidate confirmation stage of the program and use these results to probe the properties of the LCDCS. Of the 30 candidates targeted, we find statistically significant overdensities of red galaxies near 28. Of the ten additional candidates serendipitously observed within the fields of the targeted 30, we detect red galaxy overdensities near six. We test the robustness of the published LCDCS estimated redshifts to misidentification of the brighest cluster galaxy (BCG) in the survey data, and measure the spatial alignment of the published cluster coordinates, the peak red galaxy overdensity, and the brightest cluster galaxy. We conclude that for LCDCS clusters out to z~0.8, 1) the LCDCS coordinates agree with the centroid of the red galaxy overdensity to within 25'' (~150 h^{-1} kpc) for 34 out of 37 candidates with 3σgalaxy overdensities, 2) BCGs are typically coincident with the centroid of the red galaxy population to within a projected separation of 200 h^{-1} kpc (32 out of 34 confirmed candidates), 3) the red galaxy population is strongly concentrated, and 4) the misidentification of the BCG in the LCDCS causes a redshift error >0.1 in 15-20% of the LCDCS candidates. These findings together help explain the success of the surface brightness fluctuations detection method.

10 pages, 9 figures, accepted for publication in the November 10 issue of ApJ

References in corpus (5)

• The Las Campanas Distant Cluster Survey - The Catalog
• The Las Campanas Distant Cluster Survey -- The Correlation Function
• Revisiting Brightest Cluster Galaxy Evolution with the Las Campanas Distant Cluster Survey
• Cluster Galaxy Evolution from a New Sample of Galaxy Clusters at 0.3 < z < 0.9
• On the Nature of the EIS Candidate Clusters: Confirmation of z<0.6 candidates

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• Weak lensing mass reconstruction of the interacting cluster 1E0657-558: Direct evidence for the existence of dark matter
• EDisCS -- the ESO Distant Cluster Survey -- Sample Definition and Optical Photometry
• The evolution of the brightest cluster galaxies since z~1 from the ESO Distant Cluster Survey (EDisCS)
• Spectroscopy of clusters in the ESO Distant Cluster Survey (EDisCS)
• Spectroscopy of clusters in the ESO distant cluster survey (EDisCS).II. Redshifts, velocity dispersions, and substructure for clusters in the last 15 fields
• On the Incidence of Strong Gravitational Lensing by Clusters in the Las Campanas Distant Cluster Survey
• Evolution of the Early-Type Galaxy Fraction in Clusters since z = 0.8
• Noise in strong lensing cosmography
• The effect of the environment on the gas kinematics and the structure of distant galaxies
• The X-ray properties of optically-selected z>0.6 clusters in the ESO Distant Cluster Survey
• Comparison of two optical cluster finding algorithms for the new generation of deep galaxy surveys