Using Stellar Streams as a Probe for Dark Matter Substructures

The Rubin Observatory will observe, and likely discover new, stellar streams in the Milky Way (MW). Stellar streams are filamentary structures made up of stars from disrupted dwarf galaxies tidally stripped/stretched by more massive galaxies. They serve as a probe of dark matter (DM) via their gravitational interactions with DM sub-structures that create disruptions in the streams. We can learn about the mass and distribution of DM-sub-structures in the MW using observations of its stellar streams as tracers! Rubin’s high resolution will be instrumental to (i) identifying these perturbations in the streams. In addition, these observations can be (ii) compared with what simulations predict for the shape a disruption will take to (iii) refine our current models of DM (CDM, WDM, etc) and its distribution. Rubin will also observe the stellar streams of other galaxies.