NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-06-25 T13:03:11 PDT
Help | Comment | NED Home

For refcode 1993AJ....105.2064S:
Retrieve 466 NED objects in this reference.
Please click here for ADS abstract

NED Abstract

Copyright by American Astronomical Society. Reproduced by permission
1993AJ....105.2064S GRAVITATIONAL LENSING STATISTICS BASED ON A LARGE SAMPLE OF HIGHLY LUMINOUS QUASARS J. SURDEJ AND J. F. CLAESKENS Institut d'Astrophysique, Universite de Liege, Avenue de Cointe 5, B-4000 Liege, Belgium Electronic mail: surdej@astra.astroulg.ac.be., claeskens@astra.astro.ulg.ac.be D. CRAMPTON Dominion Astrophysical Observatory, 5071 west Saanich Road, Victoria British Columbia V8X 4M6, Canada Electronic mail: crampton@dao.nrc.ca A. V. FILIPPENKO Department of Astronomy, University of California, Berkeley, California 94720 Electronic mail: alex%avf.hepnet@lbl.bitnet D. HUTSEMEKERS AND P. MAGAIN Institut d'Astrophysique, Universite de Liege, Avenue de Cointe 5, B-4000 Liege, Belgium Electronic mail: hutsemek@astra.astro.ulg.ac.be, magain@astra.astro.ulg.ac.be B. PIRENNE ST-ECF, c/o ESO, Karl-Schwarzschild str. 2, D-8046 Garching bei Munchen, Germany Electronic mail: bpirenne@eso.org C. VANDERRIEST Observatoire de Meudon, DAEC, Place J. Janssen 5, F-92l95 Meudon Principal Cedex, France Electronic mail: vanderri@frmeu5l.bitnet H. K. C. YEE Department of Astronomy, University of Toronto, Toronto, Ontario, Canada M5S 1A7 Electronic mail: hyee@utorphys.bitnet Received 1992 May 15; revised 1992 December 21 ABSTRACT Results on gravitational lensing statistics applied to a sample of 469 highly luminous quasars are reported. The objects were directly imaged, either from the ground (ESO, CFH) under optimal seeing conditions, or using the Hubble Space Telescope. We have derived values for the effectiveness parameter F of galaxies, modeled by means of singular isothermal spheres, to produce macrolensed images of distant quasars, and upper limits on the density parameter {OMEGA}_L_ of compact objects with masses ~10^10^ - 10^12^ M_sun_. Adopting H_0_ = 50 km/s/Mpc, {OMEGA}_0_= 1 and {lambda} = 0, we find that at the 99.7% confidence level, 0.005 < F < 0.478 and that {OMEGA}_L_ < 0.02. A critical discussion of these results is presented. Finally, comparing the efficiencies of ground-based and space instruments used to search for gravitational lens systems among highly luminous quasars, we conclude that for the near future, ground based direct imaging characterized by a good dynamical range still constitutes the best observational strategy.
Retrieve 466 NED objects in this reference.
Please click here for ADS abstract

Back to NED Home