COSMOLOGY, COSMOMICROPHYSICS AND GRAVITATION

Автор(и)

  • A. N. Alexandrov Astronomical Observatory, Taras Shevchenko National University of Kyiv, Україна
  • V. I. Zhdanov Astronomical Observatory, Taras Shevchenko National University of Kyiv, Україна
  • S. M. Koval Astronomical Observatory, Taras Shevchenko National University of Kyiv, Україна

DOI:

https://doi.org/10.18524/1810-4215.2013.26.82486

Ключові слова:

gravitational lensing, analytic theory

Анотація

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.

Посилання

Александров О.М., Жданов В.І., Федорова О.В.: 2003, Вісник Київ. Ун-ту. Астрономія, № 39–40, 52.

Alexandrov A. N., Koval S.M., Zhdanov V.I.: 2012, Advances in Astronomy and Space Phys., 2, 184.

Alexandrov A.N., Zhdanov V.I.: 2011, Mon. Not. Roy. Astron. Soc., 417, 541.

Alexandrov A.N., Zhdanov V.I., Fedorova Е.V.: 2010, Astron. Lett., 36, 329.

Congdon A.B., Keeton C.R., Nordgren C.E.: 2008, Mon. Not. Roy. Astron. Soc., 389, 398.

Keeton C.R., Gaudi B.S., Petters A.O.: 2005, Astrophys. J. 635, 35.

Schneider P., Ehlers J., Falco E. E.: 1992, Gravitational Lenses. – Berlin: Springer.

Schneider P., Weiss A.: 1992, Astron. Astrophys., 260, 1.

Zhdanov V.I., Alexandrov A.N., Fedorova E.V., Sliusar V.M.: 2012, ISRN Astron. Astrophys., vol. 2012, ID 906951.

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Опубліковано

2013-11-08

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