  We have developed a new massively-parallel radiation-hydrodynamics code
(Cosmos) for Newtonian and relativistic astrophysical problems that also
includes radiative cooling, self-gravity, and non-equilibrium, multi-species
chemistry. Several numerical methods are implemented for the hydrodynamics,
including options for both internal and total energy conserving schemes.
Radiation is treated using flux-limited diffusion. The chemistry incorporates
27 reactions, including both collisional and radiative processes for atomic
hydrogen and helium gases, and molecular hydrogen chains. In this paper we
discuss the equations and present results from test problems carried out to
verify the robustness and accuracy of our code in the Newtonian regime. An
earlier paper presented tests of the relativistic capabilities of Cosmos.
