星系中球状星团的形成机制预研究

The globular clusters are closely related to the formaiton and evolution of galaxies. The observed properties and the mechanisms of globular clusters formation still cannot be understood well by current galaxy formation theory. This project will make use of both simulation and semi-analytical model.We will employ the evolution of baryon into the dark matter halo merger trees, which are outputed by the simulation. By doing this, we will study the formation of globular clusters and galaxies and the relation between them during their formation. The model ingredients include the collapse and merger of haloes, the infall and cooling of baryonic gas, the star formation and feedback, the formation of globular clusters, the dynamical evolution and the chemical evolution. By comparing with some scaling relations from the observation, for example, the mass function, the spatial distribution and the metallicity distribution of globular clusters, we can find the initial conditions and the initial mass function for the formaiton of globular clusters in the early stage of galaxy formation. We can aslo make some improvements on the current galaxy formation model, and get more clear about the connections of globular clusters to the formation and evolution of galaxies.

球状星团与星系的形成和演化历史密切相关。目前的星系形成理论尚不能很好地解释球状星团的观测性质和形成机制。本项目综合利用数值模拟和半解析模型优点,即在数值模拟输出的暗晕并合树中加入重子的演化,以此来研究球状星团和星系的形成以及两者在形成过程中的相互关系。模型中包括暗晕的塌缩和并合、重子气体的内落和冷却、恒星的形成与反馈、球状星团的形成、动力学演化和化学演化等。结合最新的观测结果,通过考察球状星团系统的质量函数、空间分布和金属度分布等标度律,解决星系形成早期球状星团的形成条件和初始质量函数等问题,改进现有星系形成模型,深化我们对球状星团和星系形成演化关系的认识。

球状星团与星系的形成和演化过程密切相关，研究球状星团是研究星系形成和演化的重要途径之一。该项目调查总结了球状星团在观测上的统计结论，观测对理论模型的限制，利用数值模拟和半解析模型研究球状星团形成和演化等阶段的进展。理论研究主要包括球状星团的形成、密度轮廓、初始质量函数，球状星团在质量、大小、空间上的演化，星系并合对球状星团形成和演化的影响等。通过对当前研究主要模型、相关研究结果的调研,以及对该领域尚未解决的一些难题的预研究，阐明球状星团与星系的关系，深化对球状星团和星系形成和演化的认识。