Abstract
Recent observations suggest that abundance pattern differences exist between
low metallicity stars in the Milky Way stellar halo and those in the dwarf
satellite galaxies. This paper takes a first look at what role the early
environment for pre-galactic star formation might have played in shaping these
stellar populations. In particular, we consider whether differences in
cross-pollution between the progenitors of the stellar halo and the satellites
could help to explain the differences in abundance patterns. Using an N-body
simulation, we find that the progenitor halos of the main halo are primarily
clustered together at z=10 while the progenitors of the satellite galaxies
remain on the outskirts of this cluster. Next, analytically modeled
supernova-driven winds show that main halo progenitors cross-pollute each other
more effectively while satellite galaxy progenitors remain more isolated. Thus,
inhomogeneous cross-pollution as a result of different high-z spatial locations
of each system's progenitors can help to explain observed differences in
abundance patterns today. Conversely, these differences are a signature of the
inhomogeneity of metal enrichment at early times.
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