APPLICATIONS OF STRONG-LENSING FOR SOME GRAVITATIONAL LENSES

In our work present, the application of strong-Lensing observations for some gravitational lenses have been adopted to study the geometry of the universe and to explain the physics and the size of the quasars. The first procedure was to study the geometrical of the Lensing system to determine the relation between the redshift of the gravitational observations with its distances. The second procedure was to compare between the angular diameter distances "DA" calculated from the Euclidean case with that from the Freedman models, then evaluating the diameter of the system lens. The results concluded that the phenomena are restricted to the ratio of distance between lens and source with the diameter of the lens noticing. Introduction One of the most important tasks that the astronomers have undertaken in the twentieth century is the determination of the distances of the galaxies. This work is of special importance since galaxies and clusters of galaxies make the basic structure of the universe. Thus the ability to answer fundamental questions about the origin and fat of the universe depends on how well we know the distances of galaxies [1]. Source of observations All the information of the gravitational lens systems, were taken from the CfAArizona Space Telescope Lens Survey of gravitational lenses (CASTLES survey), which including images and data observed by Hubble Space Telescope "HST" and radio images [2]. We select observations of nine gravitational lens systems, which contain enough information, available and enable, for implementing calculations. The data of observation for these nine lenses are given in Table (1). Where G denotes the accuracy of the observed data, that is type A means an accurate Lensing system, Zs is the red shift of the source, and zL is the red shift of the Lens. Table (1) The observational data for nine lenses. Image Lens Name G zs zl B0218+357 A 0.96 0.68 RXJ0911+0551 A 2.80 0.77 Q0957+561 A 1.41 0.36 PG1115+080 A 1.72 0.31 SBS1520+530 A 1.86 0.72 B1600+434 A 1.59 0.41 B1608+656 A 1.39 0.63 PKS1830-211 A 2.51 0.89 HE2149-2745 A 2.03 0.50