Abstract
Most of the known cases of strong gravitational lensing involve multiple imaging of an active galactic nucleus. The properties of lensed active galactic nuclei make them promising systems for astrophysical applications of gravitational lensing; in particular, they show structure on scales of milliseconds of arc to tens of seconds of arc, they are variable, and they are polarized. More than 20 cases of strong gravitational lenses are now known, and about half of them are radio sources. High-resolution radio imaging is making possible the development of well-constrained lens models. Variability studies at radio and optical wavelengths are beginning to yield results of astrophysical interest, such as an independent measure of the distance scale and limits on source sizes.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Greenfield P. E., Roberts D. H., Burke B. F. The double quasar 0957+561: examination of the gravitational lens hypothesis using the very large array. Science. 1980 May 2;208(4443):495–497. doi: 10.1126/science.208.4443.495. [DOI] [PubMed] [Google Scholar]
- Lawrence C. R., Schneider D. P., Schmidt M., Bennett C. L., Hewitt J. N., Burke B. F., Turner E. L., Gunn J. E. Discovery of a new gravitational lens system. Science. 1984 Jan 6;223(4631):46–49. doi: 10.1126/science.223.4631.46. [DOI] [PubMed] [Google Scholar]
- McGarrity S. T., Stephenson A. H., Webster R. O. Regulation of human neutrophil functions by adenine nucleotides. J Immunol. 1989 Mar 15;142(6):1986–1994. [PubMed] [Google Scholar]
- Roberts D. H., Greenfield P. E., Burke B. F. The double quasar 0957+561: a radio study at 6-centimeters wavelength. Science. 1979 Aug 31;205(4409):894–896. doi: 10.1126/science.205.4409.894. [DOI] [PubMed] [Google Scholar]
- Walsh D., Carswell R. F., Weymann R. J. 0957 + 561 A, B: twin quasistellar objects or gravitational lens? Nature. 1979 May 31;279(5712):381–384. doi: 10.1038/279381a0. [DOI] [PubMed] [Google Scholar]