A Summary of Observational Data of the Local Group and a Comparison to LambdaCDM

The Local group's dwarf galaxies may well be the key to connecting observation and theory in galaxy formation. I will use this thesis to outline contributions I have made to collecting data related the galaxies in the Local Group. I will also describe several uses of LambdaCDM substructure to investigate seemingly anomalous distributions of dwarf galaxies in the Local Group. The first such anomalous distribution is that of the Milky Way's brightest dwarf satellites which, while presumed to represent a complete sample, are quite different, both in number and in spacial distribution from LambdaCDM AND from those of our nearest large neighbor, the Andromeda Galaxy (M31). The conclusion drawn from this mismatch is that the MW's bright dwarf galaxies are potentially quite incomplete. The second anomalous distribution of satellites is M31's so called Great Plane of Satellites (POS), which consists of 16 dwarf galaxies that lie at a root mean square (RMS) distance of 13 kpc from a common plane and appear to be co-rotating about M31. I find that only one of the 44 high resolution simulated host halos has a great POS that is this thin, which is not corotating while several or more of the halos' thinnest POS are corotating at rates comparable to that of M31. The subhalos of the ELVIS suite of high resolution simulations serves as a simple, yet powerful, empirical tool to relate mass to tracer velocity dispersion. Using this combined with spectroscopic data which I helped to collect, I determine an M31 virial mass of 1:2 x 1012 which is consistent with mass estimates calculated from different data sets.