case western reserve university



The QUEST RR Lyrae Survey: a search for substructure in the galactic halo

Robert Zinn (Yale)

For decades the origin of the stellar halo of the Milky Way has been a central issue in the discussion of different pictures for the formation of galaxies. The recent discoveries of stellar streams in the halo have shown that a least part of it formed through the tidal destruction of dwarf satellite galaxies, in qualitative agreement with the hierarchical merger picture of galaxy formation. The QUEST RR Lyrae survey is one of several ongoing searches for halo substructures resulting from the destruction of dwarf galaxies and globular clusters. The survey techniques and results will be discussed and as will some follow-up spectroscopic observations that contrain models of the stellar streams from the Sagittarius Dwarf Spheroidal Galaxy.