High-resolution Follow-up Observations Research Articles

CLASS B0739+366: A New Two-Image Gravitational Lens System

We present the discovery of CLASS B0739 + 366, a new gravitational lens system from the Cosmic Lens All-Sky Survey. Radio imaging of the source with the Very Large Array shows two compact components separated by with a flux density ratio of similar to6:1. High-resolution follow-up observations using the Very Long Baseline Array (VLBA) at 1.7 GHz detect weak, parity-reversed jet emission from each of the radio components. Hubble Space Telescope Near Infrared Camera and Multi-Object Spectrometer (NICMOS) F160W observations detect infrared counterparts to the lensed images, as well as an extended object between them, which we identify as the lensing galaxy. Redshifts for the galaxy and lensed source have not yet been obtained. For typical lens and source redshifts of z = 0.5 and z = 1.5, respectively, preliminary mass modeling predicts a time delay of similar to7 h(-1) days in a flat Omega (M) = 1.0 verse. The small predicted time delay and weak radio components will make CLASS B0739 + 366 a challenging target for Hubble constant determination.