2000AJ....120.2879M

We present new optical observations of the z=0.282 cluster Abell 697 from Keck Observatory. Images show asymmetric disturbed structure in the cD halo and a previously unknown source that is likely a faint gravitational lens arc. A spectrum of the arc did not yield a redshift, but its spectrum and colors suggest that it lies at z>1.3. We construct plausible models for the inner cluster potential that are able to reproduce the arc, but in each case the models require the inner potential to be quite elliptical. The cD morphology and the best lens models suggest that this cluster may have undergone a recent merger and is in the process of forming its cD galaxy and halo. Analysis of X-ray data from ROSAT and ASCA suggests that the merging process is sufficiently advanced that the gas in the cluster has relaxed, and A697 lies along the L_X-T_X relation for normal clusters.