Uncovering the Nature of Dark Matter with Stellar Streams in the Milky Way

Globular clusters are large sphere-shaped congregations of stars which gradually lose their members to form long, thin stellar streams. In pristine conditions, these streams have a nearly uniform density; however, recent observations of such structures in the Milky Way have revealed disturbances that suggest a close encounter with a massive and dense perturber, quite likely a clump of dark matter. This discovery opens the exciting possibility that detailed observations of stellar streams could finally shed light on the elusive nature of dark matter—one of the hottest topics in astronomy today.

Program:

• 6:30 p.m. Doors open
• 7 p.m. Short musical performance
• 7:30 p.m. Lecture begins

About the Speaker:

Ana Bonaca, a staff scientist at Carnegie Observatories, is creating a 3D, high-resolution map of the Milky Way halo, which is dominated by dark matter. Her research employs data from ground- and space-based observatories, analyzes numerical simulations, and develops new statistical tools. Prior to joining  Carnegie Observatories, Bonaca received her Ph.D. from Yale and was a fellow at the Institute for Theory and Computation at Harvard.

Artist representation of our Milky Way Galaxy surrounded by dozens of stellar streams. | James Josephides and S5 Collaboration.

Carnegie Observatories presents the 22nd season of talks highlighting the most exciting discoveries in today’s golden age of astronomy.Carnegie Observatories scientists have transformed humankind’s understanding of the Cosmos, from the revelation of the universe’s expansion to the discovery of dark energy—and the groundbreaking work continues today. Carnegie scientists are still at the vanguard of astronomical research at the world-famous Las Campanas Observatory in Chile, home of the twin 6.5m Magellan telescopes and future site of the 24m Giant Magellan Telescope.