Stephanie Tonnesen joined the foundation in 2017 as an associate research scientist at the Center for Computational Astrophysics. Her research interests lie in the fields of galaxy formation and evolution. A focus of her research is examining how a galaxy’s environment can impact its growth. To study how galaxies evolve, Tonnesen uses both cosmological simulations spanning large regions of the ‘universe’ and smaller, galaxy-scale simulations. She completed her Ph.D. at Columbia University. Before joining the foundation, Tonnesen was a Lyman Spitzer, Jr. Postdoctoral Fellow at Princeton University and an Alvin E. Nashman Fellow at the Observatories of the Carnegie Institution for Science.