The Sloan Bright Arcs Survey: Ten Strong Gravitational Lensing Clusters and Evidence of Overconcentration

TL;DR

This paper reports on ten strong gravitational lensing galaxy clusters from the Sloan Digital Sky Survey, measuring their properties and investigating whether they are more concentrated than standard cosmological models predict.

Contribution

It provides new measurements of mass, richness, and lensing properties for these clusters and examines their concentration levels relative to cosmological expectations.

Findings

Six clusters show no evidence of overconcentration.

Four clusters exhibit overconcentration, mainly lower-mass ones.

A correlation exists between overconcentration and lower mass.

Abstract

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.