Elucidation on the Origin of First Generation Objects by HMCS-E (Heterogeneous MultiComputer System-Embedded)

宇宙中第一代天体的形成是阐明宇宙演化、星系形成和重元素产生的根本问题。该项目的目标是通过执行超高分辨率模拟来阐明宇宙中第一代天体的起源。为此，新开发了重力计算专用板“Blade-GRAPE”，并完成了每个节点嵌入Blade-GRAPE的PC机群系统COSMO模拟器“FIRST”。这是天体物理模拟专家和计算机技术专家之间的合作。第一个由256个节点和496个CPU组成，拥有两台文件服务器。前者的峰值性能为33TFLOPS，其中主机系统为3.1TFLOPS，部分Blade-GRAPES为33TFLOPS。此外，GFILE文件系统是一个可扩展的虚拟文件系统，它联合了集群节点的本地文件系统，提供了22TB的文件S…更有系统。这种混合计算机系统的发展在世界上是独一无二的。利用FIRST进行了大规模的模拟，得到了如下各种结果：(1)发现了第一代天体形成对暗物质尖点的依赖，(2)通过辐射流体动力学模拟推导了第一代恒星辐射反馈的判据，(3)提出了利用辐射流体力学形成球状星团的新图景，并对紫外线背景辐射中星团的形成进行了N体模拟。(4)原始星系电离光子逃逸几率的推导；(5)非平衡原子过程对星系团碰撞的影响；(6)星系团与卫星星系碰撞产生的“仙女座泪”新图像的提出。特别地，与以前的模拟相比，通过将质量分辨率提高两个数量级以上，获得了结果(1)。这给出了一幅第一代物体的新奇图景。较少

The formation of first generation objects in the universe is an fundamental issue to clarify the cosmic evolution, the galaxy formation, and the generation of heavy elements. The objective of the project is to elucidate the origin of first generation objects in the universe by performing ultra-high resolution simulations. For the purpose, the special purpose board for gravity calculations "Blade-GRAPE" has been newly developed, and Cosmo Simulator "FIRST", which is a PC cluster system with embedded Blade-GRAPE in each node, has been completed. This is the collaboration between experts on astrophysical simulations and those on computer technology. FIRST is composed of 256 nodes and 496CPUs, and possesses two file servers. The peak performance of FIRST is 33TFLOPS in total, where the host system is 3.1 TFLOPS and the part of Blade-GRAPEs is 33TFLOPS. Also, Gfarm file system, which is a scalable virtual file system federating local file systems of cluster nodes, is providing a 22TB file s … More ystem. The development of such a hybrid computer system is quite unique in the world.Large-scale simulations have been performed with FIRST, and a variety of results are obtained as follows : (1) discovery of the dependence on dark matter cusps of the formation of first generation objects, (2) derivation of the criteria for radiative feedback by first stars by radiation hydrodynamic simulations, (3) proposal of a new picture of globular cluster formation by radiation hydrodynamic and N-body simulations on the formation of star clusters in ultraviolet background radiation. (4) derivation of the escape probability of ionizing photons from primeval galaxies, (5) effects of non-equilibrium atomic processes on the collision of galaxy clusters, (6) proposal of a new picture of 'Andromeda tears' through the collision with a satellite galaxy. In particular, the result (1) has been obtained by raising the mass resolution by more than two order of magnitude compared to previous simulations. This gives a novel picture of first generation objects. Less