Search academic texts

Information × Registration Number 0216U001289, 0112U006957 , R & D reports Title The investigation of gravitationally lensed quasars - the way to the study of the structure of quasars and dark matter problem solving popup.stage_title Head Zheleznyak Olexandr Petrovich, Registration Date 03-02-2016 Organization Kharkov National University named after V.N. Karazin popup.description2 The object of study - the phenomenon of gravitational lens, microlensing and quasars. The purpose - to obtain the new astrophysical and cosmological information based on theoretical developments and ground-based astronomical observations, with the subsequent processing and interpretation of the data. Research methods - theoretical consideration and computer simulations of different aspects of the phenomenon of gravitational lenses, ground-0based observation, photometry and spectroscopy in the visible range, statistical and correlation analysis. The theory of gravitational lenses for a system uniform disk + central body was considered, the possibility of forming of 3 Einstein rings had been shown. Possible impact on the modern scale of distances in the Universe by gravitational lenses was reviewed. Simulation of quasar microlensing considering lensing galaxy of finite thicknessl was performed as well as analyzing of the derived results. As part of the N-body problem the influence of the initial conditions for the evolution of self-gravitating torus that is placed in the gravity field of central mass was considered. According to the observations of gravitationally lensed quasar Q2237 + 0305 a histogram of probabilities of microlensing gain was built, whose analysis gave an upper limit on the proportion of the mass of dark matter in the lensing galaxy (<50%). Confirmed the presence of extensive structure of the accretion disk around a quasar Q2237 + 0305. For gravitationally lensed quasars НЕ 0435-1223, PG1115+080, Н1413+117, SBS 1520+530 the new or improved values of time delay were obtained. Using time delay and the lens model for SBS 1520 + 530 the value of Hubble constant H0 of 66.5 km/s/MPc was calculated. The search for gravitationally lensed quasars using Sloan Sky survey data (SDSS) was performed, the new lensed quasar SDSS J1442 + 4055 was discovered. A new algorithm for estimation of time delays from lightcurves of lensed quasars which takes into account microlensing was developed. The search for microlensing events using optimal subtraction algorithm was continued, which gave as the result 26 new variable stars. A method for collimation for two-mirror telescopes of Ritchey-Chretien system was developed and implemented. Product Description popup.authors O.Кочетов І.Сінельніков В. Дудінов В.Конічек В.Цвєткова О.Баннікова О.Железняк О.Сєргєєв popup.nrat_date 2020-04-02 Close