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arXiv · 1306.5239

Chemical Abundance Patterns and the Early Environment of Dwarf Galaxies

Lauren Corlies·Kathryn V. Johnston·Jason Tumlinson·Greg Bryan
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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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Lauren Corlies, Kathryn V. Johnston, Jason Tumlinson, Greg Bryan. 2013-06-21. Chemical Abundance Patterns and the Early Environment of Dwarf Galaxies. https://doi.org/10.1088/0004-637x/773/2/105

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