A VLA/MERLIN/VLBA for Intermediate Scale Lenses and the Discovery of a New Lens System?

  • P. Augusto
  • P. N. Wilkinson
  • I. W. A. Browne
Part of the International Astronomical Union / Union Astronomique Internationale book series (IAUS, volume 173)


We are searching for small lens systems (50-250 mas or 108 – 109 M ) in a sample of ∼ 1800 flat spectrum radio sources. This is the first time a systematic search has been made “between” the VLA and VLBI resolutions. Finding any would indicate the existence of other than the “conventional” spiral/elliptical lenses (only ∼ 0.01% chance - Turner et al. (1984)). For example, faint galaxies are numerous (∼ 106 gal/deg2 - Lilly (1993), Glazebrook et al. 1995), compact (HST Medium Deep Survey (MDS) - Griffiths et al. 1994) and ideally placed for lensing (< Z >∼ 0.6 - MDS, Smail et al. (1994); c.f. Turner et al. 1984). Early-type dwarf galaxies (dE, N and cE), if extant at intermediate-z as favored by MDS are also obvious lens candidates. If no lenses are found, a limit 400 times better than the current one (Surdej et al. 1993), Ω L < 0.001, will be placed on the cosmological density of compact objects (e.g. black holes) for the above mass range.


Black Hole Spectral Index Optical Identification Compact Object Radio Astronomy 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© International Astronomical Union 1996

Authors and Affiliations

  • P. Augusto
    • 1
  • P. N. Wilkinson
    • 1
  • I. W. A. Browne
    • 1
  1. 1.Nuffield Radio Astronomy LaboratoriesUniv. of Manchester Jodrell BankMacclesfieldUK

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