The new two-image gravitational lens system CLASS B2319+051

Abstract

We report the discovery of a new two-image gravitational lens system from the Cosmic Lens All-Sky Survey, CLASS B2319+051. Radio imaging with the Very Large Array (VLA) and Multi-Element Radio-Linked Interferometer Network (MERLIN) shows two compact components with a flux density ratio of 5:1, separated by 1.36 arcsec. Observations with the Very Long Baseline Array (VLBA) resolve each of the radio components into a pair of parity-reversed subcomponents. Hubble Space Telescope (HST) observations with the Near-Infrared Camera and Multi-Object Spectrometer (NICMOS) show a bright elliptical galaxy (G1) coincident with the radio position, and a second irregular galaxy (G2) 3.4 arcsec to the northwest. Previous spectroscopic studies have indicated that these galaxies are at different redshifts: z(G1) = 0.624, z(G2) = 0.588. Infrared counterparts to the lensed radio components are not detected in the NICMOS image, and the source redshift has not yet been determined. Preliminary mass modeling based on the VLBA subcomponent data indicates that the lensing potential includes a strong external shear contribution. A VLA monitoring program is currently being undertaken to measure the differential time delay.

16 pages, 7 figs, several typos corrected, AJ in press (August 2001)

Cited by in corpus (14)

• The Cosmic Lens All-Sky Survey: I. Source selection and observations
• The Cosmic Lens All-Sky Survey:II. Gravitational lens candidate selection and follow-up
• Improved Cosmological Constraints from Gravitational Lens Statistics
• Self-Similar Models for the Mass Profiles of Early-type Lens Galaxies
• The redshift distribution of gravitational lenses revisited: Constraints on galaxy mass evolution
• The Cosmic Lens All-Sky Survey: statistical strong lensing, cosmological parameters, and global properties of galaxy populations
• Gravitational lensing reveals extreme dust-obscured star formation in quasar host galaxies
• The Gravitational Lens -- Galaxy Group Connection. II. Groups Associated with B2319+051 and B1600+434
• The Detection of Pure Dark Matter Objects with Bent Multiply Imaged Radio Jets
• Strong lensing constraints on the velocity dispersion and density profile of elliptical galaxies
• A novel search for gravitationally lensed radio sources in wide-field VLBI imaging from the mJIVE-20 survey
• Measuring gravitational lens time delays using low-resolution radio monitoring observations
• Finding Lensed Radio Sources with the VLA Sky Survey
• Cusped Mass Density Profiles and Magnification Ratios of Double Image Gravitational Lenses