The extended emission to the east seen in the VLBApls, VLBA2cm1, and
VLBA2cm2 images is not seen in our image, probably because of the
paucity of data on shorter baselines.
This is also a bright radiosource in our sample. At one arcminute North-West
there is a group around a bright galaxy (G). This group is associated with the
largest shear bar in the field (0.032) as it often happens in shear simulation
by Large Scale Structures (Wambsganss et al. 1995, ref. ?). This effect can be
understood because the shear is high when the convergence is also high at the
immediate proximity of strong critical lenses (Bartelmann & Schneider (1995 A&A
248,349)). One can condlude that it is more likely that we have a distant
cluster in E with a deep potential well. This cluster shall contribute to a
weak magnification of the QSO by itself. There is also a small clump of
galaxies in the close vicinity of the radiosource with the brightest member at
a distance of 8 arcseconds. The situation is similar to the case of the
multiple QSO 2345+007 (Bonnet et al. 1993). The nearby galaxies could be the
dominant lensing agent which provides a larger magnification, especially if the
nearby cluster has already provided a substantial part of the critical
projected mass density.
Q1508-0531 (PKS 1508-05, z_em_ = 1.191)
We find no published spectra for this object and our spectra show no
absorption lines. Spectrum #1 for this object suffers from the
flattening problem in the July 1988 spectra.