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Astron. Astrophys. 319, 365-370 (1997)

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Faint galaxies around quasars at z = 1 and gravitational lensing of distant objects

J.W. Fried

Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg, Germany (fried@mpia-hd.mpg.de)

Received 30 November 1995 / Accepted 27 July 1996


Very deep imaging data of three optically luminous radio-loud quasars with redshifts between [FORMULA] and [FORMULA] are presented. The data are complete for galaxies down to [FORMULA]. 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 ([FORMULA]) 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

SIMBAD Objects


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© European Southern Observatory (ESO) 1997

Online publication: July 3, 1998