Universe Colloquium: Discovery of a north‐south asymmetry in the distribution of local stars and its implications

by Susan Gardner (Univ. Kentucky, USA)

Wednesday 3 Jul 2013, 16:30 → 17:30 Europe/Berlin

Seminar room, basement (Universe)

Studies which would try to fix the local dark matter density through observations of the nearby stars invariably assume that the stars are in gravitational equilibrium. In recent years, however, it has become clear that the Milky Way displays many transient phenomena; it is a much more violent place than earlier thought. Susan will show how observations of the local solar neighborhood from the Sloan Digital Sky Survey can probe the vertical equilibrium of the Galactic disk, by testing the symmetries present in the stars' distribution. Our analysis reveals a failure of north-south symmetry with respect to the galactic plane and thus that vertical equilibrium is wanting. Susan will consider their result in light of other observational studies, suggest further observational tests, and finally offer a perspective on its implications for dark-matter direct detection experiments. The Universe Colloquium is followed by a social gathering with wine and cheese.