Flash: An adaptive mesh hydrodynamics code for modeling astrophysical thermonuclear flashes

We report on the completion of the first version of a new-generation simula tion code, FLASH. The FLASH code solves the fully compressible, reactive hy drodynamic equations and allows for the use of adaptive mesh refinement. It also contains state-of-the-art modules for the equations of state and ther monuclear reaction networks. The FLASH code was developed to study the prob lems of nuclear flashes on the surfaces of neutron stars and white dwarfs, as well as in the interior of white dwarfs. We expect, however, that the FL ASH code will be useful for solving a wide variety of other problems. This first version of the code has been subjected to a large variety of test cas es and is currently being used for production simulations of X-ray bursts, Rayleigh-Taylor and Richtmyer-Meshkov instabilities, and thermonuclear flam e fronts. The FLASH code is portable and already runs on a wide variety of massively parallel machines, including some of the largest machines now ext ant.