Near-field Cosmology with Stellar Streams

Abstract:

Stellar streams, the tidally-disrupted 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 revealed inconsistencies in orbital parameters and disruption rates, 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.

Bio:

Nora Shipp is a near-field cosmologist and Galactic dynamicist who uses observations and simulations of the Milky Way to understand dark matter and galaxy formation physics. She uses large astronomical surveys like the Dark Energy Survey, Gaia, and soon the Rubin Observatory LSST, along with cosmological and idealized simulations, to study the population of Milky Way satellite galaxies and star clusters across the spectrum of tidal disruption.

Learn More:

• See her faculty webpage from the University of Washington site: https://astro.washington.edu/people/nora-shipp 
• View her personal website here: https://www.norashipp.com/ 
• Read a short biography on Nora from the Vera Rubin C. Observatory staff page: https://rubinobservatory.org/explore/staff/nora-shipp 

Links:

• See the "Star Steams of NGC 5907", taken by R. Jay Gabany from Blackbird Observatory in collaboration with D. Martinez-Delado from IAC/MPIA: APOD: 2019 November 16 - The Star Streams of NGC 5907 (nasa.gov)