Wednesday, April 20, 2011, 11:00 am, Pratt Conference Room
Complexity in the Smallest Galaxies
Dr. Matthew Walker (CfA)
| Dwarf spheroidal galaxies represent the extreme lower limit of galaxy formation and are the smallest stellar systems with kinematics suggestive of an internal dark matter component. At present, cosmologically motivated models of galaxy formation have met with some success in accounting for scaling relations that have recently been observed among the Milky Way's dSph satellites. However, observationally we are still firmly in the data-gathering stage, particularly for the faintest dSphs that have been discovered only recently, and we continue to find evidence for complexities that introduce scatter in previously tight scaling relations. Here I will summarize recent observational results and present a new spectroscopic study of the Bootes I dSph, where we find direct evidence that binary orbital motions contribute significantly to the measured velocity dispersion (and ensuing mass estimates). |
Bootes I dSph
Credit: Vasily Belokurov, SDSS-II Collaboration