The aim of the Center on Astrophysical Thermonuclear Flashes is to solve the long-standing problem of thermonuclear flashes on the surfaces of compact stars such as neutron stars and white dwarfs, and in the interior of white dwarfs. This problem is remarkable for the breadth of physical phenomena involved, ranging from accretion flow onto the surfaces of these compact stars, to shear flow and Rayleigh-Taylor instabilities on the stellar surfaces, ignition of nuclear burning under conditions leading to convection, and either deflagration or detonation, stellar envelope expansion, and the possible creation of a common envelope binary star system. Because virtually every aspect of this problem represents a computational Grand Challenge, large-scale numerical simulations are at the heart of its resolution. Click on the image to view a larger version. The vertical axis is a 500 meter section through the upper layers of the neutron star, with the dark blue line tracking the surface.
Different colors represent different temperatures, with the hottest material appearing the darkest.
Overlayed is the velocity field, represented by the gray arrows, which shows material erupting from the neutron star. The reason is that astrophysical thermonuclear flashes involve a variety of distinct and complex nonlinear physical processes which have widely disparate length and time scales. Figure provided by F. X. Timmes, Michael Zingale, Kevin Olson, B. A. Fryxell, and Don Lamb. This core group includes scientists at the University of Chicago and Argonne National Laboratory. In addition, computer scientists at the Rensselaer Polytechnic Institute will join us to strengthen the partnership still further.