贫金属星中子俘获元素的丰度分布

THE ABUNDANCE DISTRIBUTION OF ELEMENTS CAPTURED BY NEUTRONS IN METAL POOR STARS

在提出的贫金属星中子俘获元素丰度的计算模型基础上研究 1 999年新发表的 2 1颗贫金属星的中子俘获元素丰度分布 .结果表明 ,对较重的中子俘获元素理论预测曲线与观测值符合得很好 ,而对较轻的中子俘获元素二者有所偏离 .这表明在贫金属环境下 ,对较重的中子俘获元素各核合成过程产生的丰度分布与太阳系中相应过程的丰度分布相似 ,但贡献比例与太阳系不同 ;而对较轻的中子俘获元素丰度分布与太阳系的丰度分布有所偏离 ;这也说明较轻的和较重的中子俘获元素的核合成场所不同 ,即具有不同的核合成机制 .同时还特别讨论了丰度观测误差对表征各核合成过程的分量系数的影响 .

Based on our model to compute the heavy element abundances in metal poor stars, the authors study the heavy element abundance distributions in 21 metal poor stars published in 1999. The results show that the heavier elements agree well with the observed data, but the lighter elements deviate from them, and this further shows that the heavier element abundances from different nucleosynthesis processes in metal poor surroundings are similar to those from corresponding processes in the solar system but the contribution ratios are different, and the lighter element abundances deviate from that of the solar system. At the same time the results suggest the nucleosynthesis sites of the lighter and heavier heavy elements are different, namely they have different nucleosynthesis mechanisms. In this paper, the authors especially discuss the influence of the observed abundance errors on the component coefficients of different nucleosynthesis processes.