An arc system with a radial gravitational image in the cluster MS 2137-23

This Letter presents the first detection of a radial gravitational image candidate in a cluster of galaxies. In addition, the field of the cluster MS 2137-23 (z=0.315) contains a large arc and a few arclets. The radial image is embedded within the halo of the central cD galaxy and can be seen only with high-resolution images. The color and brightness of this image are similar to other arc(let)s and strongly favor the radial gravitational image hypothesis. The radial image implies a small core radius for the cluster