Are The Ultra-faint Galactic Satellites The Fossils Of The First Galaxies?
Abstract
We present the results from a new set of CDM simulations suggesting that a fraction of the recently discovered ultra-faint dwarf population consists of the fossil remnants of galaxies that formed the majority of their stars before reionization. Our new simulations allow us to map the distribution of fossil and non-fossil dwarfs in the Local Group and compare the simulated maps to observations. We show good agreement between our simulations and observations of the ultra-faints in both their radial distribution within the Milky Way virial radius and their stellar properties. However, the properties of the faintest ultra-faint satellites found within 50 kpc of the Galactic Center do not agree with being well preserved fossils of the first galaxies, perhaps because they are modified by tidal effects. We also find some discrepancies with respect to the number of dwarfs in regions outside of the Milky Way virial radius.
- Publication:
-
American Astronomical Society Meeting Abstracts #215
- Pub Date:
- January 2010
- Bibcode:
- 2010AAS...21545708B