Spectroscopic redshifts for seven lens galaxies

The use of gravitationally lensed quasars for cosmological applications and as probes of galaxy structure and evolution requires knowledge about the lens redshift, which is unknown for a large fraction of lenses. We report Very Large Telescope observations of 11 lensed quasars, designed to measure the redshifts of their lens galaxies. We successfully determined the redshifts for seven systems, five of which were previously unknown. The securely measured redshifts for the lensing galaxies are: HE 0047-1756 z 0: 408; PMN J0134-0931 z 0: 766; HE 0230-2130 z = 0.522; HE 0435-1223 z = 0.455; SDSS 0924+021 z = 0.393; LBQS 1009-025 z = 0.871; and WFI J2033-472 z = 0.658,all with uncertainties of 0.001. For four additional systems (BRI 0952-0115, Q1017-207, Q1355-2257, and PMN J1632-003) we estimate tentative redshifts based on some features in their spectra.