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Assist.

Jon Judež

Department
Department of Physics
Assist. Jon Judež

I am an astrophysicist at the University of Ljubljana, Faculty of Mathematics and Physics. I work as part of the research group led by Prof. Dr. Maruša Bradač. Our team utilizes data from the groundbreaking James Webb Space Telescope, enabling us to explore previously inaccessible regions of the universe. My primary focus is on investigating the earliest galaxies, studying their growth and evolution during the first billion years of cosmic history.

I completed my undergraduate studies in physics at the Faculty of Mathematics and Physics and pursued further education at Stockholm University, where I earned a Master's degree in astrophysics. During this time, I also gained valuable experience in research of planets orbiting other stars. Currently, I am a young researcher at our faculty, engaged in doctoral studies.

I am part of the Guaranteed Time Observations (GTO) program CANUCS (CAnadian NIRISS Unbiased Cluster Survey) on the James Webb Space Telescope. I am also a member of the VENUS collaboration (Vast Exploration for Nascent, Unexplored Sources).

We observe areas of massive galaxy clusters, which, due to their large mass and dark matter contents, cause strong gravitational lensing of distant galaxies behind them. This gives us a unique insight into young galaxies during the Epoch of Reionisation. Lensing strongly stretches and magnifies these distant galaxies and I am developing numerical methods to model those effects in order to obtain intrinsic morphologies of these galaxies. In other words, I am taking the distorted images of lensed galaxies and finding out what they really look like.

In this way I am researching galaxy growth and assembly, inner structures such as stellar clusters, and also highly magnified Little Red Dots (LRDs).