ARCRAIDER II: Arc search in a sample of non-Abell clusters

TL;DR

This paper reports a search for gravitational arcs in a sample of X-ray luminous, medium redshift galaxy clusters, identifying numerous arc candidates and potential lensing events, expanding understanding of gravitational lensing in non-Abell clusters.

Contribution

It introduces the ARCRAIDER sample based on ROSAT Bright Survey clusters and presents the first systematic search for gravitational arcs in this specific non-Abell cluster sample.

Findings

Over 35 arc/arclet candidates identified

66% of clusters show potential lensing features

Includes possible radial arc and quasar triple image

Abstract

We present a search for gravitational arcs in a sample of X-ray luminous, medium redshift clusters of galaxies. The sample of clusters is called ARCRAIDER, is based on the ROSAT Bright Survey (RBS) and fulfills the following criteria: (a) X-ray luminosity Lx>=0.5x10^45erg/s (0.5-2keV band), (b) redshift range 0.1<=z<=0.52, (c) classified as clusters in the RBS, (d) not a member of the Abell catalogue and, finally, (e) visible from the ESO sites La Silla/Paranal (declination \delta<=20deg). In total we found more than 35 (giant) arc/arclet candidates, including a possible radial arc, one galaxy-galaxy lensing event and a possible quasar triple image in 14 of the 21 clusters of galaxies. Hence 66% of the sample members are possible lenses.