1600+434 - A NEW GRAVITATIONAL LENS SYSTEM

We report the discovery of a new gravitational lens system associated with the flat-spectrum radio source 1600+434. The system has been foun d in a new large survey of such radio sources. It consists of a 1.4-ar csec double radio source with an associated optical double at the same position and orientation, and with an almost identical flux density r atio to that in the radio. Spectra of the light from two optical image s show broad emission lines with a redshift of 1.61. The spectral data are not of sufficient quality to show that both images have identical spectra. Nevertheless, we argue that the probability that 1600+434 is indeed a lensed system is very high.