Smoothed Particle Hydrodynamics Coupled with Radiation Transfer

We have constructed a brand-new radiation hydrodynamics solver based upon Smoothed Particle Hydrodynamics, which works on a parallel computer system. The code is designed to investigate the formation and evolution of first-generation objects at z 10, where the radiative feedback from various sources plays important roles. The code can compute the fraction of chemical species e, H⁺, H, H⁻, H₂, and H₂⁺ by fully implicit time integration. It also can deal with multiple sources of ionizing radiation, as well as radiation at Lyman–Werner band. We compare the results for a few test calculations with the results of one-dimensional simulations, in which we find good agreements with each other. We also evaluate the speedup by parallelization, which is found to be almost ideal, as long as the number of sources is comparable to the number of processors.