Serhieiev O. Gravitationally lensed system SBS 1520 + 530 : optical observations and modeling

The thesis is dedicated to the study of a gravitational lensing effect and based on optical observations of the gravitationally lensed system SBS 1520 + 530. The fundamentals of the theory, examples and cosmological applications of gravitational lensing are presented. Modern approaches to processing of astronomical CCD images are discussed. Algorithms and methods for photometry of gravitationally lensed quasars, and the analysis of the obtained light curves for determining the time delays are presented. Photometry of the CCD images of GLS SBS 1520 + 530 in the VRI spectral bands obtained at the 1.5-m AZT-22 telescope of the Maidanak Observatory (Uzbekistan) in 1999-2009 was carried out. The values of (V-I) color indices versus R magnitudes and (V-I) versus (V-R) were determined on the basis of the obtained quasar light curvesof images A and B. The light curves of quasar images of the SBS 1520+530 system demonstrate the evidence of microlensing effect. Its quantitative estimation was obtained in this work. The time delay between two images A and B (dt = 96 days) was determined taking into account the microlensing effect . The model of the SBS 1520+530 gravitationally lensed system was constructed. It provides a possibility to estimate the value of the Hubble constant H0 = 66.5 km/c/Mpc. Numerical statistical modeling of the microlensing process in the SBS 1520 + 530 system was performed, using GPU computing technology (CUDA). Estimation of the most probable size of quasar emitting region, as well as a mass of a microlenses of the lensing galaxy, were estimated.