Formation of Dwarf Galaxies in Reionized Universe with Heterogeneous Multi-computer System

摘要

HMCS (Heterogeneous Multi-Computer System) is a very powerful and ideal computational environment for large scale computational astrophysics simulations including multiple physical phenomena. In this system, general purpose and special purpose parallel processing systems are involved to realize very high performance computation. We have constructed a system with MPP and PC-cluster as general purpose side and GRAPE-6 gravity engine as special purpose side. We perform 3D radiation smoothed-particle-hydrodynainics (RSPH) simulations on the formation and the photoevaporation of subgalactic objects (M ～ 10~8 - 10~9 solar mass). We confirm the suppression of the formation of small galaxies after the reionization. We also find that the galaxies that undergo violent photoevaporation process, still retain certain amount of stars, which are formed at small scale high density peaks. These cooled components merge with each other when the dark matter halo of the whole system is formed. It is also found these low mass galaxies should have large mass-to-light ratio, and these systems could be the progenitor of dwarf spheroidal galaxies in Local Group.