A possible gravitational lens in the Hubble Deep Field South

We model an apparent gravitational lens system HDFS 2232509–603243in the Hubble Deep Field South. The system consists of a blue V = 25 mag arc separated by 0. ′′9 from a red V = 22 mag elliptical galaxy. A mass distribution which follows the observed light distribution with a constant mass-to-light ratio can fit the arc component positions if external shear is added. A good fit is also obtained with simple parameterized models, and all the models predict a fourth image fainter than the detection limit. The inferred mass-to-light ratio is ∼ 15 in solar units if the lens is at z = 0.6. The lens models predict a velocity dispersion of ∼ 280 km s−1 which could be confirmed with spectroscopy. Subject headings: cosmology: observations — galaxies: individual (HDFS 2232509– 603243) — gravitational lensing