r-process元素产量、产区及星系化学演化

The Yields of R-process Elements and Chemical Evolution of the Galaxy

在观测到的极贫金属星Ba元素随金属丰度分布区域的左边界与单颗Ⅱ型超新星污染区域的r-过程元素丰度对应的假定下,采用Tsujimoto给出的Ⅱ型超新星爆发Mg元素的产量,利用Tsujimoto提出的方法,根据观测到的极贫金属星Ba和Mg丰度的左边界数值计算各种质量超新星r-过程的产量,得出星系中r-过程核合成的主要质量区间.根据所得到的不同质量Ⅱ型超新星r-过程的产量关系,改进Fields等人所提出的方法,解释观测到的贫金属星中子俘获元素的弥散性(scatter);根据三成份(晕、厚盘和薄盘)多相模型(气体、分子云、大小质量恒星以及剩余物质),利用所得到的Ⅱ型超新星的r-过程的产量计算了r-过程元素的均匀化学演化.

We assume that the left boundary to plan has a one-to-one correspondence to the Ba yield from individual SN Ⅱ ; others correspond to the yields of several supernovae. So we use Mg yield and the same method of Tsujimoto, then obtain main mass range for r-process. According to the obtained the function of r-process yield and SN Ⅱ progenitor mass,we improve the method of Fields, explain scatters of n-capture elements in metal poor stars and take advantage of the model named three-zone multiphase model in order to study the chemical evolution of the Galaxy.