Lee Hartmann

Professor Hartmann studies the processes by which cold clouds of gas and dust fragment and then collapse, forming stars and a surrounding rotating disk; and the evolution of disks which ultimately can form planets. Because protostellar clouds form in complex, highly structured and turbulent gas, time-dependent (magneto)hydrodynamics is required to follow fragmentation and collapse to stars and disks.  Similarly, the evolution of planet-forming disks involves both gravitational and magnetic turbulence. Simulations of cloud and disk evolution over the necessary timescales (10⁵ to 10⁶ years) with reasonable resolution demands extensive parallel processing.