First lensed quasar systems from the VST-ATLAS survey: one quad, two
  doubles and two pairs of lensless twins
  We have analyzed images from the VST ATLAS survey to identify candidate
gravitationally lensed quasar systems in a sample of WISE sources with W1 - W2
> 0.7. Results from followup spectroscopy with the Baade 6.5 m telescope are
presented for eight systems. One of these is a quadruply lensed quasar and two
are doubly lensed systems. Two are projected superpositions of two quasars at
different redshifts. In one system two quasars, though at the same redshift,
have very different emission line profiles, and constitute a physical binary.
In two systems the component spectra are consistent with the lensing
hypothesis, after allowing for micro-lensing. But as no lensing galaxy is
detected in these two, we classify them as lensless twins. More extensive
observations are needed to establish whether they are in fact lensed quasars or
physical binaries.
