Place: 4421 Sterling Hall, Coffee and cookies 3:30 PM, Talk begins 3:45 PM
Speaker: Professor Elena D'onghia, UW Madison Astronomy Department
Abstract: The Gaia satellite is currently mapping the phase-space of a few million stars in the solar neighborhood showing time-varying phenomena. About 350,000 stars within 200 pc of the Sun are identified in streams, bundles of stars that move together in the same direction with a velocity that is distinct from neighboring
stars. I will present a set of N-body simulations of the Milky Way disk that shows the role of a long stellar bar and spiral arms in understanding the complex kinematics of the solar vicinity. Finally, the passage of Sagittarius dwarf galaxy induces rapid time-variations in the potential that lead to a significant bias of the Oort limit through the Jeans modeling. This calls for the development of non-equilibrium methods to estimate the dynamical matter density locally and in the outer disk.