%0 Journal Article
%T B1359+154: A Six Image Lens Produced by a z=1 Compact Group of Galaxies
%A D. Rusin
%A C. S. Kochanek
%A M. Norbury
%A E. E. Falco
%A C. D. Impey
%A J. Lehar
%A B. A. McLeod
%A H. -W. Rix
%A C. R. Keeton
%A J. A. Munoz
%A C. Y. Peng
%J Physics
%D 2000
%I arXiv
%R 10.1086/322251
%X HST V and I-band observations show that the gravitational lens B1359+154 consists of six images of a single z_s=3.235 radio source and its star-forming host galaxy, produced by a compact group of galaxies at z_l = 1. VLBA observations at 1.7 GHz strongly support this conclusion, showing six compact cores with similar low-frequency radio spectra. B1359+154 is the first example of galaxy-scale gravitational lensing in which more than four images are observed of the same background source. The configuration is due to the unique lensing mass distribution: three primary lens galaxies lying on the vertices of a triangle separated by 0.7 arcsec (4/h kpc), inside the 1.7 arcsec diameter Einstein ring defined by the radio images. The gravitational potential has additional extrema within this triangle, creating a pair of central images that supplement the ``standard'' four-image geometry of the outer components. Simple mass models consisting of three lens galaxies constrained by HST and VLBA astrometry naturally reproduce the observed image positions but must be finely-tuned to fit the flux densities.
%U http://arxiv.org/abs/astro-ph/0011505v1