Stellar Streams as Probes of Galactic Structure and Dark Matter Halos

When a globular cluster or a dwarf galaxy is tidally disrupted due to its host galactic potential, the unbound stars assemble into coherent filamentary structures known as stellar streams. Given the ordered nature of their dynamical formation mechanism, streams are highly sensitive to the structure and substructure of the underlying potential in which they evolve. Nearly 100 such streams have been observed in the Milky Way, and over the coming decade, we expect to detect thousands more in nearby galaxies with the Roman Space Telescope, the Euclid Mission, and the Rubin Observatory. In this talk, I will review the various galactic characteristics that a stellar stream can probe, including the shape and mass of the galaxy, the evolution of the galactic potential, non-axisymmetric components like a galactic bar, and the nature of dark matter substructure. I will show how these galactic characteristics can lead to similar morphological manifestations, and demonstrate methods that can be used to break these degeneracies. Finally, I will discuss how the anticipated detection of streams in other galaxies provides both new opportunities and new challenges for applying these techniques to study the nature of dark matter halos.