The Sloan Bright Arcs Survey: Ten Strong Gravitational Lensing Clusters   and Evidence of Overconcentration
  We describe ten strong lensing galaxy clusters of redshift 0.26-0.56 that were found in the Sloan Digital Sky Survey. We present measurements of richness, mass and velocity dispersion for the clusters. We find that in order to use the mass-richness relation from Johnston et al. (2007), which was established at mean redshift of 0.25, it is necessary to scale measured richness values up by 1.47. We also present measurements of Einstein radius, mass and velocity dispersion for the lensing systems. The Einstein radii are all relatively small, between 5.4-13 arcseconds. Finally we consider if there is evidence that our clusters are more concentrated than standard cosmology would predict. We find that six of our clusters do not show evidence of overconcentration, while four of our clusters do. We note a correlation between overconcentration and mass, as the four clusters showing evidence of overconcentration are all lower-mass clusters. 
Matthew P. Wiesner, Huan Lin, Sahar S. Allam, James Annis, Elizabeth   J. Buckley-Geer, H. Thomas Diehl, Donna Kubik, Jeffre...
astro-ph.CO