The XMM/2dF survey III: Comparison between optical and X-ray cluster detection methods

Abstract

We directly compare X-ray and optical techniques of cluster detection by combining SDSS photometric data with a wide-field ($\sim 1.8$ deg${}^2$) XMM-{\em Newton} survey in the North Galactic Pole region. The optical cluster detection procedure is based on merging two independent selection methods - a smoothing+percolation technique, and a Matched Filter Algorithm. The X-ray cluster detection is based on a wavelet-based algorithm, incorporated in the SAS v.5.2 package. The final optical sample counts 9 candidate clusters with richness of more than 20 galaxies, corresponding roughly to APM richness class. Three, of our optically detected clusters are also detected in our X-ray survey. The most probable cause of the small number of optical cluster candidates detected in our X-ray survey is that they are relatively poor clusters, fainter than the X-ray flux limit (for extended sources) of our survey $f_x(0.3-2\mathrm{keV})\simeq 2\times 10^{-14}ergc{m}^{-2}{s}^{-1}$.

9 pages, 5 figures, MNRAS accepted

References in corpus (4)

• The Galaxy Luminosity Function and Luminosity Density at Redshift z=0.1
• The Evolution of X-ray Clusters of Galaxies
• A Merged Catalog of Clusters of Galaxies from Early SDSS Data
• The XMM-Newton/2dF survey I: X-ray properties of normal galaxies

Cited by in corpus (16)

• Measuring the mean and scatter of the X-ray luminosity -- optical richness relation for maxBCG galaxy clusters
• RASS-SDSS Galaxy Cluster Survey. V. The X-ray-Underluminous Abell Clusters
• ChaMP Serendipitous Galaxy Cluster Survey
• The 2XMMi/SDSS Galaxy Cluster Survey I. The first cluster sample and X-ray luminosity-temperature relation
• Clustering of X-Ray-Selected AGN
• X-ray Galaxy Clusters in NoSOCS: Substructure and the Correlation of Optical and X-ray Properties
• Cosmology with clusters of galaxies
• The X-ray properties of optically-selected z>0.6 clusters in the ESO Distant Cluster Survey
• The Serendipitous XMM-Newton Cluster Athens Survey (SEXCLAS): Sample selection and the cluster log N - log S
• The X-ray Properties of Optically Selected Clusters of Galaxies
• XMM-{\em Newton} Observations of Optically Selected SDSS Clusters
• The XMM Cluster Survey: evolution of the velocity dispersion -- temperature relation over half a Hubble time
• Abell 315: reconciling cluster mass estimates from kinematics, X-ray, and lensing
• Detection of X-ray galaxy clusters based on the Kolmogorov method
• The XMM-Newton/2dF survey-VIII: The extended X-ray sources
• Optical Confirmation of X-ray selected Galaxy clusters from the Swift AGN and Cluster survey with MDM and Pan-STARRS Data (Paper III)