The Stromlo Missing Satellites Survey

Abstract

According to cosmological theory, density fluctuations of Cold Dark Matter (CDM) form the first structures in the Universe. The gravitational potential wells of these dark matter halos suck in primordial gas and provide the seeds for the formation of stars via energy dissipation and cooling, a billion years after the Big Bang. The observational Universe today is filled with these galaxies, the prime repositories of shining baryonic matter. For obvious reasons, most of the detected and catalogued galaxies are intrinsically the largest and the brightest, those that can be seen from the greatest distance and are most easily studied against the night sky. Ironically, a major limitation on our ability to develop a consistent model that describes how galaxies emerged out of dark matter comes from the incompleteness of our picture of the nearby universe, in particular from the lack of a detailed understanding of the phenomenon dwarf galaxies.