Andrew R. Wetzel

From protogalaxy through thick and thin: Why did the Milky Way evolve in three kinematic phases?

Abstract APOGEE and Gaia data suggest the Milky Way’s kinematic structure evolved through three distinct phases: a disordered protogalaxy, which ‘spun up’ into a thick stellar disk, and then ‘cooled down’ to a final cold, thin stellar disk. We use a suite of FIRE-2 cosmological z...

The Star Formation History and Evolution of the Ultra-Diffuse M81 Satellite F8D1

Abstract We present deep Hubble Space Telescope (HST) imaging of one of the nearest ultra-diffuse galaxies (UDGs) outside of the Local Group: F8D1, a satellite of M81 known to be tidally disrupting. UDGs are an enigmatic and diverse population, with evolutionary pathways ranging...