Gravitational Lensing: Proceedings of a Workshop Held in Toulouse, France September 13-15, 1989 (Lecture Notes in Physics)

This is an exhaustive review of our theoretical and observational knowledge of gravitational lensing 10 years after the discovery of the first lensed quasar, Q0957+561. Gravitational optics, optical, infrared, and radio observations of quasar-lens candidates, microlensing, arcs in clusters of galaxies, and radio rings are presented. In particular, the continuing survey of quasar-lens candidates, the new measurement of the time delay in 0957+561, the suspended microlensing effect through the galaxy 2237+030, as well as the discovery of new arcs and the measurement of new redshifts for two of them are presented. Numerous papers on the modelling of arcs and rings show how it should be possible to probe dark matter with these unexpected gravitational telescopes. Finally, tables summarize all the lens candidates we know today. Pictures of gravitational lensing.- Determination of cosmological parameters by the gravitational lens effect.- Cosmic gravitational diagnostics.- Gravitational redshifts and lensing by large scale structures.- What the present observed lens systems tell about the lensing agent.- Gravitational lens models with elliptical geometry.- Amplification near a gravitational lens macro-caustic.- Statistics of lensing on extended sources.- Observational aspects of gravitational lensing.- Quasar-galaxy associations.- A search for gravitational lensing among highly luminous quasars : observational strategy and survey.- A search for gravitational lensing among highly luminous quasars: new results.- Gravitational magnification effects on distant 3CR galaxies.- 0957+561: The time delay revisited.- The time delay of Q0957-+-561 A,B from 10 years of optical monitoring.- Application of image processing techniques in a search for gravitational lenses and quasar pairs.- A search for gravitational lenses and quasar pairs and the discovery of a new multiple QSO system.- Evolution and gravitational lensing in quasar absorption line systems.- Preliminary analysis of high-resolution spectra for UM 673 A & B.- Bidimensional spectrography of the “clover leaf” H1413+117 at sub-arcsec. Spatial resolution.- The MIT search program for gravitational lenses.- First epoch VLBI observations of the gravitational lens system 2016+112.- X-ray observations of gravitational lenses.- Consequences of gravitational lensing for gamma radiation from 3C273.- Searching for cosmic strings (A la recherche des cordes perdues).- Microlensing.- Microlensing calculations with a hierarchical tree code: New results.- Statistical investigations of the amplification near gravitational lens caustics.- The deconvolution of the quasar structure from the lightcurve of a high amplification event with the regularisation method.- The Hamburg quasar monitoring program at Calar Alto: Analyses of micro-lensing variability.- Photometric monitoring of 2237+0305.- Spectrophotometry of 0957+561 and the micro-lensing effect.- IR imaging and the light curve of 2237+030.- Clusters of galaxies: A new observable class of gravitational lenses.- Lensing the background population of galaxies.- The redshift distribution of faint galaxies – Implications for gravitational lensing.- The theory and practice of radio ring lenses.- Lens and source models for ARCS in cluster Abell 370 and Cl 2244.- Modeling the giant arcs in A370 and A2390.- New results from the gravitational telescope.- Probing rich galaxy clusters with mini-arcs.- Gravitationally lensed arcs as galaxy redshift indicators.- Spatial correlation in gravitationally lensed images.- Optical-infrared studies of arcs in Abell 370.- Spectroscopy of arcs in Cl2244-02 and A370 (A5).- First results on the spectroscopy of the arc-like object in Abell 2390.- Deep photometry of C1.2244-02 in U colour with an electronographic camera.- Concluding remarks.- Gravitational lens candidates.