Determination of galaxy masses by the gravitational lens effect

1986 ◽  
Vol 309 ◽  
pp. 467 ◽  
Author(s):  
U. Borgeest
Keyword(s):  
Gravitational Lens ◽  
Lens Effect ◽  
Galaxy Masses

Gravitational Lens Effect: An Observational Test

Science ◽  
1966 ◽  
Vol 151 (3706) ◽  
pp. 73-74 ◽  
Author(s):  
W. A. Feibelman
Keyword(s):  
Gravitational Lens ◽  
Lens Effect ◽  
Observational Test

A diffraction limit on the gravitational lens effect

1981 ◽  
Vol 78 (1) ◽  
pp. 199-210 ◽  
Author(s):  
Robert J. Bontz ◽  
Mark P. Haugan
Keyword(s):  
Diffraction Limit ◽  
Gravitational Lens ◽  
Lens Effect

scholarly journals VLBI Observations of Gravitational Lens Systems

1988 ◽  
Vol 129 ◽  
pp. 191-199
Author(s):  
Edwin L. Turner
Keyword(s):  
Gravitational Lens ◽  
Lens System ◽  
Additional Test ◽  
System A ◽  
Vlbi Observations ◽  
Vlbi Data ◽  
Cosmological Tests ◽  
Superluminal Expansion ◽  
Additional Constraints

Four specific and particularly powerful types of possible VLBI lens studies are discussed. First, comparison of mas scale structure in putative pairs of images separated by arc seconds can provide a powerful additional test of the lens hypothesis in specific candidate systems. Second, VLBI searches for lens systems with image separations too small for resolution by optical or VLA searches will limit (or even determine!) the cosmological density of condensed objects with individual masses ∼ 106M⊙. Third, study of multiply imaged superluminal expansion events will allow a determination of the light travel time delay between different images in a lens system, a quantity which is quite difficult to measure by other means but which would allow profound cosmological tests. Fourth, VLBI data can be used to determine relative image parities and even the full magnification matrix of various images in a lens system, thus providing powerful additional constraints on detailed lens models. Finally, the speculative possibility of detecting Galactic stellar lensing events using VLBI techniques is discussed.

scholarly journals Photometric Monitoring Of The Lensed QSO 0957+561

1996 ◽  
Vol 173 ◽  
pp. 53-54
Author(s):  
D. Sinachopoulos ◽  
M. Burger ◽  
E. van Dessel ◽  
M. Geffert ◽  
M. Thibor ◽  
...  
Keyword(s):  
Time Delay ◽  
Gravitational Lens ◽  
Large Field ◽  
Photometric Study ◽  
First Results ◽  
Photometric Monitoring

We present our first results of a photometric monitoring project of the twin quasar 0957+561. This project aims mainly at the improvement of the determination of the time delay ΔT(A,B) for this gravitational lens, since the “time delay controversy on QSO 0957+561 (is) not yet decided” (Pelt et al. 1994). In addition, the quite large field of the CCD used allows also a long-term astrometric and photometric study of stars and galaxies in the field within a radius of about 10 arcminutes around the lens.

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