I primarily explore how the Local Group, together with numerical simulations, can inform galaxy formation theory. Most recently, I have begun working with the FIRE (Feedback in Realistic Environments) collaboration to include hydrodyanmics, star formation, and stellar/supernova feedback in cosmological simulations of the Local Group.

A large set of movies illustrating the evolution of Milky Way-mass galaxies in the FIRE simulations are available here.

A similar set of movies for the recently completed ELVIS on FIRE suite is in progress.


ELVIS on FIRE applies the FIRE models for star formation, feedback, etc. to environments that are designed to mimic the real Local Group, with analogues to both the Milky Way and Andromeda. The FIRE physics yield dwarf galaxy populations that match observations both in terms of the number and internal structure of dwarf galaxies around the Milky Way. The image above cycles between the 3D dark matter, stellar, and gas density in one simulation.


The publicly available Exploring the Local Volume in Simulations (ELVIS) suite, consisting of 12 Local Group-like halo pairs and 24 mass-matched isolated halos, allows for a statistical understanding of the LG and its history, and provides the basis for predictions regarding future observations. ELVIS has enabled over forty publications since its inception, and continues to provide an ideal laboratory for exploring ΛCDM predictions for structure in the Local Group.

Dwarf Galaxies

Dwarfs are the most dark matter dominated objects in the Universe, and they are crucial for understanding the particle nature of dark matter, the earliest epochs of galaxy formation, the aftermath of reionization, and much more. Their abundances, internal structures, total masses, star formation histories, metallicities, and phase-space distributions around the Milky Way and Andromeda galaxies all provide stringent tests of ΛCDM. (Image credit: ESO DSS-2)


First Author Publications

Nth Author Publications