Analytic Expressions for Mean Magnification by a Quadrupole Gravitational Lens
Open Access
- 20 September 2002
- journal article
- research article
- Published by American Astronomical Society in The Astrophysical Journal
- Vol. 577 (1) , 51-56
- https://doi.org/10.1086/342163
Abstract
We derive an analytic expression for the mean magnification due to strong gravitational lensing, using a simple lens model: a singular isothermal sphere embedded in an external shear field. We compute separate expressions for two-image and four-image lensing. For four-image lensing, the mean magnification takes a particularly simple form: μ4 = 3.6/ , where γ is the external shear. We compare our analytic results with a numerical evaluation of the full magnification distribution. The results can be used to understand the magnification bias that favors the discovery of four-image systems over two-image systems in flux-limited lens surveys.Keywords
All Related Versions
This publication has 19 references indexed in Scilit:
- Resolved nuclear CO(1-0) emission in APM 08279+5255: gravitational lensing by a naked cusp?Monthly Notices of the Royal Astronomical Society, 2002
- Gravitationally lensed radio sources in the Jodrell Bank-VLA Astrometric SurveyMonthly Notices of the Royal Astronomical Society, 1999
- Lens models with density cuspsMonthly Notices of the Royal Astronomical Society, 1998
- The Gravitationally Lensed Radio Source MG 0751+2716The Astronomical Journal, 1997
- Shear and Ellipticity in Gravitational LensesThe Astrophysical Journal, 1997
- The Flat‐Spectrum Radio Luminosity Function, Gravitational Lensing, Galaxy Ellipticities, and CosmologyThe Astrophysical Journal, 1996
- Biases, selection effects and image multiplicities in the Jodrell Bank-VLA gravitational lens surveyMonthly Notices of the Royal Astronomical Society, 1996
- The implications of lenses for galaxy structureThe Astrophysical Journal, 1991
- The quadrupole gravitational lensThe Astrophysical Journal, 1987
- Fermat's principle, caustics, and the classification of gravitational lens imagesThe Astrophysical Journal, 1986