The FIRST-Optical-VLA Survey for Lensed Radio Lobes

Abstract

We present results from a survey for gravitationally lensed radio lobes. Lensed lobes are a potentially richer source of information about galaxy mass distributions than lensed point sources, which have been the exclusive focus of other recent surveys. Our approach is to identify radio lobes in the FIRST catalog and then search optical catalogs for coincident foreground galaxies, which are candidate lensing galaxies. We then obtain higher-resolution images of these targets at both optical and radio wavelengths, and obtain optical spectra for the most promising candidates. We present maps of several radio lobes that are nearly coincident with galaxies. We have not found any new and unambiguous cases of gravitational lensing. One radio lobe in particular, FOV J0743+1553, has two hot spots that could be multiple images produced by a z = 0.19 spiral galaxy, but the lensing interpretation is problematic. Subject headings: gravitational lensing — galaxies: individual (FOV J0743+1553) — galaxies: spiral — radio continuum: galaxies 1.