Proučevanje vesolja z gravitacijskim lečenjem v novi dobi teleskopskih pregledov neba

Galaxy clusters can magnify supernovae through strong gravitational lensing, thereby creating multiple images of the same supernova. This phenomenon enables measurements of cosmological parameters, primarily the Hubble constant. Gravitationally lensed supernovae are intrinsically rare events, with fewer than ten discovered to date. In this thesis, we study the prospects for detecting strongly lensed supernovae behind galaxy clusters, with a focus on two upcoming observatories: the Vera C. Rubin Observatory (Rubin) and the Nancy Grace Roman Space Telescope (Roman). We employed two approaches: one focusing on known multiply-imaged galaxies behind cluster fields, along with supernova rates specific to those galaxies, and another based on the expected number of multiply-imaged supernovae in a given volume behind a galaxy cluster. We collected all galaxy clusters in literature with multiply-imaged galaxies that have high-quality spectroscopic and photometric data for the first estimate approach, or a well constrained lens model for the second. We provide lensed supernova yield predictions for 46 clusters visible to Rubin, as well as for 9 observable by Roman’s High Latitude Time Domain Survey. In addition, we created a publicly available index of gravitational lensing models and publications on galaxy clusters. The index represents a comprehensive database of lensing models, including those not used in our work. We predict that the number of multiply-imaged supernovae discovered by Rubin in its first three years of operation is 3.95±0.89 from the first approach, or 4.94±1.02 from the second. Based on recent proposed observing strategies for Roman’s High Latitude Time Domain Survey, the expected number of multiply-imaged supernovae ranges from 0.38±0.15 to 5.2±2.2, depending on the specific cluster observed. As the exact fields to be targeted by the survey remain a matter of discussion, we provide a recommendation for the field selection, that either the cluster MACS J0553.4-3342 or Abell 1758a should be observed by the survey to maximize the number of potential multiply-imaged supernova discoveries. We furthermore conclude that Rubin offers great prospects for detecting multiply-imaged supernovae, and that if adequate follow-up campaigns are conducted, these capabilities will enable precise measurements of cosmological parameters that are independent of conventional probes.