Dark Matter and Galactic Dynamics

par Matt Walker (Harvard -- Smithsonian Center for Astrophysics)

vendredi 12 juil. 2013, 14:00 → 15:00 Europe/Paris

Auditorium (Annecy-le-Vieux)

I will explain how to use the motions of stars to learn about the nature of particles. More specifically, I will translate the stellar kinematics observed in the nearest, smallest and 'darkest' galaxies into a test of the standard hypothesis that dark matter consists of 'cold' and 'collisionless' (i.e., weakly interacting) particles. This model seems to require that baryon-driven processes (e.g., energetic feedback from supernova explosions) alter the internal structure of galactic dark matter halos systematically with respect to predictions derived from cosmological N-body simulations. I will identify future work -- both observational and theoretical -- that I expect will tell definitively whether such reconciliation is energetically feasible or whether the dark matter model requires additional complexity.