| Autor: |
A. N. Alexandrov, V. I. Zhdanov, S. M. Koval |
| Jazyk: |
angličtina |
| Rok vydání: |
2013 |
| Předmět: |
|
| Zdroj: |
Odessa Astronomical Publications, Vol 26, Iss 2, Pp 169-171 (2013) |
| Druh dokumentu: |
article |
| ISSN: |
1810-4215 |
| DOI: |
10.18524/1810-4215.2013.26.82486 |
| Popis: |
We derive approximate formulas for the coordinates and magnification of critical images of a point source in a vicinity of a cusp caustic arising in the gravitational lens mapping. In the lowest (zero-order) approximation, these formulas were obtained in the classical work by Schneider&Weiss (1992) and then studied by a number of authors; first-order corrections in powers of the proximity parameter were treated by Congdon, Keeton and Nordgren. We have shown that the first-order corrections are solely due to the asymmetry of the cusp. We found expressions for the second-order corrections in the case of general lens potential and for an arbitrary position of the source near a symmetric cusp. Applications to a lensing galaxy model represented by a singular isothermal sphere with an external shear y are studied and the role of the second-order corrections is demonstrated. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
|
