An Efficient Search for Gravitationally-Lensed Radio Lobes

Abstract

We performed an automated comparison of the FIRST radio survey with the APM optical catalog to find radio lobes with optical counterparts. Based on an initial survey covering ~3000 square degrees, we selected a sample of 33 lens candidates for VLA confirmation. VLA and optical observations of these candidates yielded two lens systems, one a new discovery (J0816+5003), and one of which was previously known (J1549+3047). Two other candidates have radio lobes with galaxies superposed, but lack evidence of multiple imaging. One of our targets (J0958+2947) is a projected close pair of quasars (8'' separation at redshifts 2.064 and 2.744). Our search method is highly efficient, with >5% of our observing targets being lensed, compared to the usual success rate of <1%. Using the whole FIRST survey, we expect to find 5--10 lenses in short order using this approach, and the sample could increase to hundreds of lensed lobes in the Northern sky, using deeper optical surveys and planned upgrades to the VLA. Such a sample would be a powerful probe of galaxy structure and evolution.

Submitted to ApJ, 2000.07.28, revised 2000.09.12. Minor revisions and new observations of best example. Eleven eps figures. Uses AASTeX/LaTeX, psfig2.tex

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Cited by in corpus (16)

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• The FIRST-2MASS Red Quasar Survey II: An anomalously high fraction of LoBALs in searches for dust-reddened quasars
• The redshift distribution of gravitational lenses revisited: Constraints on galaxy mass evolution
• FIRST `Winged' and `X'-shaped Radio Source Candidates
• The genesis of morphologies in extended radio sources: X-shapes, off-axis distortions and giant radio sources
• Galaxy Number Counts and Implications for Strong Lensing
• Cosmic Evolution of Virial and Stellar Mass in Massive Early-Type Galaxies
• FIRST "Winged" and X-shaped Radio Source Candidates: II. New Redshifts
• Improving efficiency in radio surveys for gravitational lenses
• The FIRST-Optical-VLA Survey for Lensed Radio Lobes
• Investigation of flat spectrum radio sources by the interplanetary scintillation method at 111 MHz
• Strong gravitational lensing with upcoming wide-field radio surveys
• Finding Lensed Radio Sources with the VLA Sky Survey
• A Morphological Identification and Study of Radio Galaxies from LoTSS DR2. I. The "Winged'' Radio Galaxies
• A doubled double hotspot in J0816+5003 and the logarithmic slope of the lensing potential
• J0316+4328: a Probable "Asymmetric Double" Lens