The Study of the evolution of star clusters, galaxies, clusters of galaxies by ultra-fast Special-purpose Computer for many-body problem

多体问题超高速专用计算机研究星团、星系、星系团的演化

• 批准号: 04102002
• 负责人: SUGIMOTO Daiichiro
• 金额: $ 120.96万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Specially Promoted Research
• 财政年份: 1992
• 资助国家: 日本
• 起止时间: 1992 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-04102002/
• 关键词: Special-purpose computer; Globular clusters; Galaxies; Clusters of galaxies; Gravitational many-body system; 重力多体問題; 星団; 並列処理; 多体問題; 並列計算機; LSI; 重力

In this year, we continued the simulation of the evolution of globular clusters, galaxies and clusters of galaxies using GRAPE-4. In addition, we developed a new host interface board for GRAPE-4, which allows use to use faster host computers. For this new host interface board we adopted the PCI bus, which is now available on wide variety of computers from personal computers to supercomputers. We bought high-performance workstations with this PCI interface as new host computers, fast and large tape systems to save the data, and enhanced the memory capacity of host computersMain scientific results of this year include (a) The determination of the structure of the central region of the CDM halo, (b) The study of the evolution of the massive black hole binaries in merging galaxies, and (c) the systematic survey of the effect of encounters to the structure of galaxies in the clusters.Here we briefly summarize (a). Previous simulations of the formation of the dark matter halo in galactic scale typically employed only 20,000-30,000 particles. Because of this small number of particles, the structure within 10 kilo parsec was strongly affected by the two-body relaxation effect, which is not present in real galaxies. We performed the simulation using 786,432 particles, and successfully determined the structure down to 1 kilo parsec. The result is that the inner region is almost isothermal with temperature slightly decreasing inward, which is inconsistent with the observed structure of large elliptical galaxies. This result and the simulation of galaxy merger with central black holes strongly suggest the dynamical effect of massive central objects is crucial to explain the observed structure of large ellipticals.

在这一年，我们继续使用GRAPE-4模拟球状星团，星系和星系团的演化。此外，我们还为GRAPE-4开发了一个新的主机接口板，允许使用更快的主机。对于这个新的主机接口板，我们采用了PCI总线，它现在可用于从个人计算机到超级计算机的各种计算机。我们购买了具有这种PCI接口的高性能工作站作为新的主机，快速和大容量的磁带系统来保存数据，并增强了主机的内存容量。今年的主要科学成果包括：（a）确定CDM晕中心区域的结构，（B）研究合并星系中大质量黑洞双星的演化，（c）星系团中星系碰撞对星系结构影响的系统研究。以前在银河系尺度上对暗物质晕形成的模拟通常只使用了20，000 - 30，000个粒子。由于粒子数量很少，10千秒差距内的结构受到两体弛豫效应的强烈影响，这在真实的星系中是不存在的。我们使用786，432个粒子进行了模拟，并成功地确定了1千秒差距的结构。结果是，内部区域几乎是等温的，温度向内略有下降，这与观测到的大椭圆星系的结构不一致。这一结果以及星系与中心黑洞合并的模拟强烈表明，大质量中心天体的动力学效应对于解释观测到的大椭圆星系结构至关重要。

项目成果

J.Makino: "Merging of Galaxies with Central Black Holes II. Evolution of the Black Hole Binary and the Structure of the Core" The Astrophysical Journal. 478 (in press). (1997)

J.Makino：“星系与中央黑洞的合并 II。黑洞双星的演化和核心结构”《天体物理学杂志》。

T.Fukushige and J.Makino: "N-body Simulations of Gulaxy Formation on GRAPE-4 Special-Purpose Computer" Proceedings of Supercomputing '96. (CD-ROM). (1996)

T.Fukushige 和 J.Makino：“GRAPE-4 专用计算机上的星系形成的 N 体模拟”超级计算 96 论文集。

Toshiyoki Fukushige and Junichiro Makino: "The Origin of Cusps in Dark Matter Halos" The Astrophysical Journal Letters. (in press). (1997)

Toshiyoki Fukushige 和 Junichiro Makino：“暗物质光环尖点的起源”《天体物理学杂志快报》。

D.Sugimoto etal.,: "GRAPE Project for a Dedicated Tera-flops Computev" The First Aizu International Symposium. 38-44 (1995)

D.Sugimoto 等人：“专用 Tera-flops Computev 的 GRAPE 项目”第一届会津国际研讨会。

T.Fukushige,M.Taiji,et al.: "A Highly-Parallelized Special-Purpose Computer for Many-Body Simulations with an Arbitrary Central Force : MD-GRAPE" The Astrophysical Journal. 468. 51-61 (1996)

T.Fukushige、M.Taiji 等人：“用于具有任意中心力的多体模拟的高度并行专用计算机：MD-GRAPE”《天体物理学杂志》。