Figure 9 from Simpson et al. 2017 in prep.
Dwarf Galaxies and the Local Group
My focus in galaxy formation is on dwarf galaxies and the Local Group. I have done simulation work on isolated, low mass dwarf galaxies, exploring the interplay of stellar feedback and reionization. I have also studied the effects of momentum feedback on dwarf galaxy formation. In the context of the Local Group, I am currently working on a study of ram pressure stripping and quenching of satellite galaxies using the Auriga simulations.
Cosmic Rays
I am interested in the effects of supernova feedback on galaxies generally, however, recently I have focused specifically on feedback from cosmic rays. Cosmic rays are a significant source of pressure in the ISM of the Milky Way and may be dynamically important in large-scale galactic gas flows.
The movie to the right shows the impact of cosmic rays on the ISM and their ability to drive outflows. See Simpson et al. 2016 for more details.
Figure 1 from Simpson et al. 2015
Hydrodynamic Simulation Codes
I am a part of the development teams of the Enzo and AREPO simulation codes. These codes are highly-parallel, hydrodynamic and nbody simulation codes used for a wide array of astrophysical problems, particularly for cosmology problems. My development in both codes has focused on techniques for modeling supernova feedback. In Enzo, I have also developed techniques for improving the efficiency of cosmological zoom simulations through the use of must-refine particles.
I am also a part of the AGORA collaboration for galaxy simulation code comparison as part of the Enzo team. My work on this project has focused on cosmological nbody simulations.