Constraining Dark Matter In External Galaxies Using Stellar Streams

Although the shapes of galaxies’ dark matter distributions have been extensively theorized and simulated, they remain challenging to measure. This project focuses on using stellar streams – elongated structures formed when smaller satellite systems are tidally disrupted by the gravitational forces of a larger host galaxy – to map the total gravitational potential, sourced in part by the dark matter. In this project I build off work analyzing deep-space images from the European Space Agency’s Euclid mission to identify galaxies hosting stellar streams. These streams serve as dynamical tracers of the host galaxy’s total gravitational potential, which we model. By further modeling and subtracting the baryonic contribution, I isolate the dark matter component and derive its mass distribution and shape.