Class B0631+519: Last of the Class Lenses

Journal Article · Tue May 31 00:00:00 EDT 2005 · Mon.Not.Roy.Astron.Soc.361:259-271,2005

DOI:https://doi.org/10.1111/j.1365-2966.2005.09170.x· OSTI ID:890857

York, Tom; Jackson, N; Browne, I W.A.; Koopmans, L V.E.; McKean, J P; Norbury, M A; Biggs, A D; Blandford, R D; de Bruyn, A G; Fassnacht, C D; Myers, S T; Pearson, T J; Phillips, P M; Readhead, A C.S.; Rusin, D; Wilkinson, P N

We report the discovery of the new gravitational lens system CLASS B0631+519. Imaging with the VLA, MERLIN and the VLBA reveals a doubly-imaged flat-spectrum radio core, a doubly-imaged steep-spectrum radio lobe and possible quadruply-imaged emission from a second lobe. The maximum separation between the lensed images is 1.16 arcsec. High resolution mapping with the VLBA at 5 GHz resolves the most magnified image of the radio core into a number of sub-components spread across approximately 20 mas. No emission from the lensing galaxy or an odd image is detected down to 0.31 mJy (5{sigma}) at 8.4 GHz. Optical and near-infrared imaging with the ACS and NICMOS cameras on the HST show that there are two galaxies along the line of sight to the lensed source, as previously discovered by optical spectroscopy. We find that the foreground galaxy at z=0.0896 is a small irregular, and that the other, at z=0.6196 is a massive elliptical which appears to contribute the majority of the lensing effect. The host galaxy of the lensed source is detected in the HST near-infrared imaging as a set of arcs, which form a nearly complete Einstein ring. Mass modeling using non-parametric techniques can reproduce the near-infrared observations and indicates that the small irregular galaxy has a (localized) effect on the flux density distribution in the Einstein ring at the 5-10% level.

• Research Organization: Stanford Linear Accelerator Center (SLAC)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-76SF00515
• OSTI ID: 890857
• Report Number(s): SLAC-PUB-11256; astro-ph/0505093
• Journal Information: Mon.Not.Roy.Astron.Soc.361:259-271,2005, Journal Name: Mon.Not.Roy.Astron.Soc.361:259-271,2005
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
Astrophysics
ASTRO
CAMERAS
DISTRIBUTION
FLUX DENSITY
GALAXIES
LENSES
RESOLUTION
SIMULATION
SPECTROSCOPY