Building the Stellar Halo Through Feedback in Dwarf Galaxies
  We present a new model for the formation of stellar halos in dwarf galaxies.
We demonstrate that the stars and star clusters that form naturally in the
inner regions of dwarfs are expected to migrate from the gas rich, star forming
centre to join the stellar spheroid. For dwarf galaxies, this process could be
the dominant source of halo stars. The effect is caused by stellar
feedback-driven bulk motions of dense gas which, by causing potential
fluctuations in the inner regions of the halo, couple to all collisionless
components. This effect has been demonstrated to generate cores in otherwise
cuspy cold dark matter profiles and is particularly effective in dwarf galaxy
haloes. It can build a stellar spheroid with larger ages and lower
metallicities at greater radii without requiring an outside-in formation model.
Globular cluster-type star clusters can be created in the galactic ISM and then
migrate to the spheroid on 100\thinspace Myr timescales. Once outside the inner
regions they are less susceptible to tidal disruption and are thus long lived;
clusters on wider orbits may be easily unbound from the dwarf to join the halo
of a larger galaxy during a merger. A simulated dwarf galaxy
($\text{M}_{vir}\simeq10^{9}\text{M}_{\odot}$ at $z=5$) is used to examine this
gravitational coupling to dark matter and stars.
