Nicholas Metropolis Award for Outstanding Doctoral Thesis Work in Computational Physics Talk: Astrophysical Simulations in the Era of Massively-Parallel Computation

In this talk, I will describe my thesis work developing Cholla, a new hydrodynamics code for astrophysics that was designed to run natively on the graphics processing units (GPUs) that power the world’s fastest supercomputers. By harnessing the power of this new technology, Cholla is allowing us to run astrophysics simulations with unprecedented numerical resolution, leading to new insights regarding the physical structure of gas in galaxies. In addition to describing the design of the Cholla code (including details of both physical and numerical algorithms), I will also discuss the results of a recent project using Cholla to explore an interesting problem in galaxy evolution - the physics of galactic winds. Star-forming galaxies are commonly observed to be driving gas out at a variety of densities, temperatures, and velocities. These outflows are invoked to explain the discrepancy between the dark matter halo mass function and the stellar mass function of low-mass galaxies. Using petascale simulations run with Cholla on the Titan supercomputer, we can better resolve the hydrodynamic interactions between phases in these outflows, allowing us to constrain their origin and evolution. This combination of new software with new computer architectures has ushered in a new era of massively-parallel astrophysics simulations.