Local Group Dwarf Galaxies in the LCDM Cosmology
Author | : Erik Jon Tollerud |
Publisher | : |
Total Pages | : 263 |
Release | : 2012 |
ISBN-10 | : 1267367334 |
ISBN-13 | : 9781267367334 |
Rating | : 4/5 (34 Downloads) |
Book excerpt: Dwarf galaxies include some of the most extreme low-luminosity objects in the universe, and provide important windows into a wide variety of processes in galaxy formation and evolution. In this thesis, I describe a series of comparisons between observations of dwarf galaxies and predictions of the LCDM concordance cosmology, with a focus on Local Group satellites. I first correct the Milky Way satellite luminosity function for luminos- ity bias under the assumption of a typical LCDM satellite distribution, finding consistency with the observations and a prediction of possibly hundreds of faint Milky Way satellites. I also describe a new technique to connect the luminous properties of these satellites (as well as brighter galaxies) to their expected dark matter halo properties. I further consider the brightest Milky Way satellite, the Large Magellanic cloud (LMC), in a cosmological context by comparing it to similar galaxies in the Sloan Digital Sky Survey (SDSS). This shows that LCDM n-body simulations provide a good match to observations of such satel lites. I also show that, while LMC-like satellites are not uncommon, the LMC is unusual in how blue it is, especially given that the SDSS satellites are significantly redder than typical galaxies of their size. Finally, I present a large new data for faint satellites of M31, the nearest galaxy similar to the Milky Way, providing a second data point for detailed studies of faint satellite systems. I also show that its satellites are very similar in their general properties to that of the Milky Way satellites.