CCA Special Seminar: Adrian Price-Whelan

Title: Mapping dark matter with stellar streams: Imprints of Galaxy-scale dynamical phenomena

Abstract: As they orbit within a host galaxy like the Milky Way, tidally-disrupting satellite galaxies and star clusters produce streams of stars that nearly trace out the orbit of their progenitor system. These resulting stellar streams therefore provide otherwise unobservable information about the galactic force field and are one of the most promising tools for measuring the sub-galaxy-scale properties of dark matter. However, streams that form in more realistic galactic environments also record many other interesting dynamical phenomena, such as time-dependent perturbations from the Galactic bar and the gravitational influence of the Magellanic Clouds. I will show recent work on a few of the most prominent streams in the Milky Way that demonstrate that streams not only have the capacity to deliver precise constraints on the nature of dark matter, but are also sensitive to the physical processes at work during the assembly and evolution of our Galaxy. I will argue that, in order to deliver accurate and meaningful constraints on dark matter in either of these contexts, we must understand how these other complex–but interesting–effects may bias our inferences and conclusions from modeling individual streams.

To join the talk remotely to go this Zoom link.