Dynamical effects of stellar feedback on low-mass galaxies
Using galaxy simulations from the Feedback in Realistic Environments (FIRE) project, I have shown that feedback-driven gas outflows can couple energy from stellar feedback to the orbits of stars and dark matter. This causes stars to migrate coherently outward, producing metallicity gradients and apparent outside-in quenching signatures similar to those observed in nearby dwarf galaxies.
Because stellar feedback disrupts star forming gas clouds, the star formation rate of low-mass galaxies varies in concert with the dynamics and spatial distribution of stars and dark matter. I have shown that this leads to observationally testable predicted correlations between galaxies' star formation rates and their sizes, velocity dispersions, and dark matter density profiles.
Feedback-driven outflows are dynamically important when (a) star formation is bursty, (b) the potential is shallow, and (c) the baryon fraction is relatively high. I have shown that these conditions are satisfied not only in dwarf galaxies, but also in the high-redshift progenitors of Milky Way-mass galaxies. As a result, many of the dynamical processes discussed above also apply. In particular, I predict the oldest stars in the Milky Way to have migrated outwards since they formed, so that ancient stars are found primarily in the inner stellar halo at $z=0$.
For details, see the paper Where are the most Ancient Stars in the Milky Way?. Some popular science coverage related to these papers can be found in this article. A follow-up investigation can be found in this paper.