Master Thesis Defense by Rachel Gledhill
Title: Mass and Magnification in Abell 370: Updating the lens model of a Hubble Frontier Fields galaxy cluster with JWST
Abstract: Gravitational lensing in galaxy clusters is a powerful tool with which to study both the large scale mass distribution of some of the most massive structures in the Universe and the magnified galaxies in their backgrounds. In this thesis, I will present a new parametric lens model of the matter distribution in the galaxy cluster Abell 370 made using new data from the James Webb Space Telescope. I use NIRCAM and NIRISS data to evaluate the systems of multiple images of background galaxies and discuss how they have been changed and improved by JWST. I use these systems as strong lensing constraints to construct a lens model. Using a magnification map derived from the model, I also discuss the properties of a newly spectroscopically confirmed multiply imaged galaxy at z=7.69. I constrain its properties with SED fitting and discuss the impact of different prior assumptions on the results.
Supervisor:
- Victoria Bellinger Strait, University of Copenhagen, Niels Bohr Insitute
Censor:
- Hans Kjeldsen, Aarhus University