We present the first results of the SOAR Gravitational Arc Survey ( SOGRAS ) .
The survey imaged 51 clusters in two narrow redshift intervals centered at z = 0.27 and z = 0.55 , targeting the richest clusters in each interval .
Images were obtained in the g ^ { \prime } , r ^ { \prime } , and i ^ { \prime } bands using the SOAR Optical Imager ( SOI ) , with a median seeing of 0.82 ^ { \prime \prime } , 0.74 ^ { \prime \prime } , and 0.69 ^ { \prime \prime } , respectively , in these filters .
Most of the survey clusters are located within the Sloan Digital Sky Survey ( SDSS ) Stripe 82 region and all of them are in the SDSS footprint .
Photometric calibration was therefore performed using SDSS stars located in our SOI fields .
We reached for galaxies in all fields the detection limits of g \sim 23 , r \sim 22.5 , and i \sim 22 for S / N = 3 .
As a by-product of the image processing , we generated a source catalog with 21280 entries , the vast majority of which are galaxies , where we list their positions , magnitudes , and shape parameters .
We compared our galaxy shape measurements to those of local galaxies and concluded that they were not strongly affected by seeing .
From the catalog data , we are able to identify a red sequence of galaxies in most clusters in the lower z range .
We found 16 gravitational arc candidates around 8 clusters in our sample .
They tend to be bluer than the central galaxies in the lensing cluster .
A preliminary analysis indicates that \sim 10 \% of the clusters have arcs around them , with a possible indication of a larger efficiency associated to the high- z systems when compared to the low- z ones .
Deeper follow-up images with Gemini strengthen the case for the strong lensing nature of the candidates found in this survey .