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Faint galaxies around quasars at z = 1 and gravitational lensing of distant objects
Received 30 November 1995 / Accepted 27 July 1996
Very deep imaging data of three optically luminous radio-loud quasars with redshifts between and are presented. The data are complete for galaxies down to . There is no evidence for excess numbers of galaxies around the quasars; foreground galaxy clusters are excluded by the data as well as clusters with richness classes greater than 1 associated with the quasars. We find clear evidence for gravitational lensing for two quasars. It is further shown that due to the high surface density of galaxies all distant () objects are moderately affected by gravitational lensing; the amplification factors are estimated to be in the range 1.1-1.5.
Key words: quasars: general gravitational lensing galaxies: halos
© European Southern Observatory (ESO) 1997
Online publication: July 3, 1998