Lensed Arcs and Inner Structure of Abell 697
Abstract
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 LX-TX relation for normal clusters. Based on observations obtained at the W. M. Keck Observatory, which is operated as a scientific partnership by the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The observatory was made possible by the generous financial support of the W. M. Keck Foundation.
- Publication:
-
The Astronomical Journal
- Pub Date:
- December 2000
- DOI:
- 10.1086/316843
- arXiv:
- arXiv:astro-ph/9909166
- Bibcode:
- 2000AJ....120.2879M
- Keywords:
-
- galaxies: clusters: individual (Abell 697);
- Galaxies: Elliptical and Lenticular;
- cD;
- Cosmology: Gravitational Lensing;
- Astrophysics
- E-Print:
- LaTeX