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

本项目的主要目标是建立一个宇宙流体力学代码，这是定量研究原星系和原星系团演化所必需的，并建立一个理论模型，以分析和补充的方式解决上述问题。具体地说，我们的研究成果总结如下：(1)我们编写了一个基于光滑粒子流体动力学方法并能适当考虑气体辐射过程的宇宙学代码。(2)我们导出了引力束缚物体形成和毁灭率的解析表达式。结合非线性球面模型，计算了单个原始星系团发出的热轫致辐射光谱，并对星系团产生的宇宙x射线背景通量和光谱进行了理论预测。(3)虽然最近在室女座星系团中发现了造父变星，更多的星系为哈勃常数H_0 - 80km/sec/Mpc提供了额外的支持，但其他距离指标建议的值相对较低，H_0 - 50km/sec/Mpc。为了探索局部确定的H_0与其全局平均值显著不同的观点，我们考虑了嵌入在空间平坦宇宙中的局部开放宇宙模型。我们找到了全局哈勃常数下限的解析表达式，以及局部宇宙中给定哈勃常数值的宇宙年龄上限的解析表达式。我们计算了超新星核心旋转坍缩的引力波形式。比较各种角动量分布的结果，我们发现，只要银河系中出现了旋转的超新星，LIGO就可以探测到这样的信号。另一方面，我们开发了一种新的广义相对论流体力学代码，该代码假定球对称并采用全隐式格式。我们认为这个代码对研究延迟机制很有用。少

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