Broadband Photometry of 105 Giant Arcs: Redshift Constraints and Implications for Giant Arc Statistics

Understand

We measure the photometric properties of 105 giant arcs that were identified in systematic searches for galaxy-cluster-scale strong lenses in the Second Red-Sequence Cluster Survey (RCS-2) and the Sloan Digital Sky Survey (SDSS).

• The cluster lenses span 0.2 < z_lens < 1.2 in redshift, with a median z_lens = 0.58.
• Using broadband color criteria we sort the entire arc sample into redshift bins based on u-g and g-r colors, and also r-z colors for the ~90% of arcs that have z-band data.
• This analysis yields broad redshift constraints with 71 +5 -4 % of the arcs at z > 1.0, 64 +6 -4 % at z > 1.4, 56 +5 -4 % at z > 1.9, and 21 +4 -2 % at z > 2.7.