Numerical study of evolution of proto-galaxies and proto-clusters for observational cosmology in the next generation.

下一代观测宇宙学中原星系和原星团演化的数值研究。

• 批准号: 05640312
• 负责人: SUTO Yasushi
• 金额: $ 1.34万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05640312/
• 关键词: Proto-galaxy; Clusters of galaxies; Observational cosmology; Numerical simulation; Supernova; 粒子法

The prinicpal goal of the present project is to develop a cosmological hydrodynamic code which is indispensible in quantitatively examining the evolution of proto-galaxies and proto-clusters, and to construct a theoretical model which can approach the above problem in a analytical and complementary manner. To be more specific, the results of our research are summarized as follows :(1) We have written up a cosmological code which is based on the smoothed particle hydrodynamic method and can properly take into account the gas-radiative processes.(2) We have derived analytical expressions for formation and destruction rates of gravitationally bound objects. Combining with the nonlinear spherical model, we computed the thermal bremsstrahlung spectrum emitted from individual proto-clusters of galaxies, and then made theoretical predictions of the cosmic X-ray background flux and spectrum due to the clusters of galaxies.(3) While the recent discovery of the Cepheid variables in the Virgo clu … More ster galaxies puts additional support for the Hubble constant H_0 - 80km/sec/Mpc, a relatively lower value H_0 - 50km/sec/Mpc is suggested by other distance indicators. In order to explore an idea that locally determined H_0 is significantly different from its global average, we considered a model of a locally open universe embedded in the spatially flat universe. We found analytic expressions for the lower limit on the global Hubble constant, and the upper limit on the age of the universe with a given value for the Hubble constant in the local universe.We calculated the gravitational wave form from a rotationally collapsing supernova core. Comparing the results for various angular momentum distributions, we found that LIGO can detect such a signal provided that a rotating supernova occurs in our galaxy. On the other hand, we have developed a new general relativistic hydrodynamics code in which spherical symmetry is assumed and fully implicit scheme is adopted. We think this code is useful to study the delayd mechanism. Less

本项目的主要目标是建立一个定量研究原星系和原星系团演化所必需的宇宙学流体动力学程序，并建立一个理论模型，以分析和补充的方式处理上述问题。具体来说，我们的研究成果概括如下：（1）我们编写了一个基于光滑粒子流体力学方法的宇宙学程序，该程序能适当地考虑气体辐射过程。(2)我们导出了引力束缚物体的形成和破坏速率的解析表达式。结合非线性球模型，计算了单个星系团的热韧致辐射谱，并对星系团产生的宇宙X射线背景通量和谱进行了理论预测。(3)虽然最近在室女座clu中发现造父变星， ...更多信息 ster星系对哈勃常数H_0 - 80 km/sec/Mpc的进一步支持，其它距离指示器建议的H_0 - 50 km/sec/Mpc值相对较低。为了探索局域决定的H_0与其全局平均值有显著差异的观点，我们考虑了一个嵌入在空间平坦宇宙中的局域开放宇宙模型。我们找到了全局哈勃常数下限的解析表达式，以及局部宇宙中哈勃常数给定值时宇宙年龄上限的解析表达式，并计算了旋转坍缩的超新星核的引力波形式。比较各种角动量分布的结果，我们发现LIGO可以检测到这样的信号，只要我们的星系中发生旋转超新星。另一方面，我们开发了一个新的广义相对论流体力学程序，其中假设球对称，并采用全隐式格式。我们认为这段代码对研究delayd机制很有用。少

项目成果

佐々木伸、高原文郎、須藤靖: "A simple model of cosmological reionization" Progress of Theoretical Physics. 90. 85-96 (1993)

Shin Sasaki、Fumio Takahara、Yasushi Sudo：“宇宙再电离的简单模型”理论物理学进展 90. 85-96 (1993)。

Haruhiko Ueda, Makoto Itoh and Yasushi Suto: "Clusters and Groups of Galaxies as Cosmological Probes" The Astrophysical Journal. 408. 3-16 (1993)

Haruhiko Ueda、Makoto Itoh 和 Yasushi Suto：“作为宇宙学探测器的星系团和星系群”《天体物理学杂志》。

牧野伸義,須藤靖: "X-ray gas mass fraction in the Shapley supercluster and its implication on the cosmological baryon-density parameter" Publications of the Astronomical Society of Japan. 45. L13-L19 (1993)

Nobuyoshi Makino、Yasushi Sudo：“沙普利超星系团中的 X 射线气体质量分数及其对宇宙学重子密度参数的影响”，日本天文学会出版物 45。L13-L19 (1993)。

Shoichi Yamada and Katsuhiko Sato: "Numerical Study of Rotating Core Collapse in Supernova Explosions" The Astrophysical Journal. 434. 268-276 (1994)

Shoichi Yamada 和 Katsuhiko Sato：“超新星爆炸中旋转核心塌陷的数值研究”《天体物理学杂志》。

山田章一,佐藤勝彦: "Numerical study of rotating core collapse in supernova explosions" The Astrophysical Journal. 434. 268-276 (1994)

Shoichi Yamada、Katsuhiko Sato：“超新星爆炸中旋转核心塌陷的数值研究”《天体物理学杂志》434. 268-276 (1994)。