University of Pennsylvania Astrophysics Seminar

Near-field Cosmology with Stellar Streams

Stellar streams, the tidal remnants of globular clusters and dwarf galaxies orbiting throughout the Milky Way’s halo, are some of the most powerful tools in the study of near-field cosmology. In particular, they are sensitive probes of the distribution and properties of dark matter across multiple scales, from the smallest subhalos, to the entire dark matter halo, as well as being excellent tracers of the growth and structure of our Galaxy. Thanks to recent large photometric, astrometric, and spectroscopic surveys, the population of stellar streams around the Milky Way is finally being revealed. In this talk, I will present the discovery, characterization, and modeling of the Milky Way stellar streams. I will also present the first comparative studies of stream populations in observations and cosmological simulations, which have revealed inconsistencies in orbital parameters, as well as a wealth of potentially yet to be detected stellar streams. In addition, I will present plans to use upcoming surveys like the Rubin Observatory LSST in order to discover and analyze tidal structures throughout the Milky Way and across the local Universe. These data will further revolutionize the study of near-field cosmology, and reveal the answers to critical questions about the structure and assembly of our Galaxy and the nature of dark matter.

Date & Time

April 03, 2024 | 3:30pm – 5:00pm


U.Penn, David Rittenhouse Laboratory, 4E19


Nora Shipp, Carnegie Mellon