FLASH: A Multidimensional Hydrodynamics Code for Modeling Astrophysical Thermonuclear Flashes

We report on the completion of the first version of a new-generation simulation code, FLASH. The FLASH code solves the fully-compressible, reactive hydrodynamic equations, allowing for the use of adaptive mesh refinement. It also contains state-of-the-art modules for the equation of state and thermonuclear reaction networks. FLASH was developed to study the problems of thermonuclear flashes on the surfaces of neutron stars and white dwarfs and in the interiors of white dwarfs. We expect, however, that FLASH will be useful for solving other astrophysical problems. The first version of this code has been subjected to a large suite of test cases, and it is currently being used for production simulations of X-ray bursts, the Rayleigh-Taylor and Richtmyer-Meshkov instabilities, and thermonuclear flame fronts. FLASH is modular, extensible, and portable, and it already runs on a wide variety of massively parallel machines, including some of the largest now in existence. This work is supported by the U.S. Department of Energy under Grant No. B341495 to the Center for Astrophysical Thermonuclear Flashes at the University of Chicago.