Physics Colloquium - Dwarf-Dwarf Interactions in the Local Group

Event Date: 

Tuesday, February 9, 2016 - 4:00pm

Event Location: 

  • Broida 1640

Speaker:

Alis Deason, Lick Observatory

Abstract:

Dwarf galaxies currently present the biggest challenge to the LambdaCDM model. The proximity of the dwarf satellite population in the Local Group allows us to confront this prevailing theory with observations. It is well-known that these dwarf satellites interact with their massive host, however, we generally ignore any interaction between the dwarf galaxies themselves. This oversight may be an important missing ingredient in our comparisons between observed dwarfs and subhalos in simulations.

In this talk, I discuss the importance of dwarf-dwarf mergers and group infall in the context of LambdaCDM simulations. These simulations show that such interactions can no longer be ignored, and may be particularly important for the lowest mass dwarfs, or "ultra-faint" galaxies. I also discuss possible observational signatures of dwarf-dwarf interactions, and the promise of future surveys to identify associations between satellite dwarfs and/or substructures in our Galaxy.