在线阅读 --自然科学版 2003年4期《S-过程元素丰度分布规律的研究》
S-过程元素丰度分布规律的研究--[在线阅读]
张凤华1,2, 刘伟伟1,2, 张波2
1. 沧州师范专科学校物理系, 河北沧州 061001;

2. 河北师范大学物理学院, 河北石家庄 050016
起止页码: 360--363页
DOI:
摘要
利用指数辐照理论的解析解研究了AGB星S-过程元素的丰度分布规律.结果表明,在低金属丰度下,AGB星核合成产量强烈依赖于金属丰度,但如果将S-m(88<A≤204)部分按质量数分为S-mh(140≤A≤204)和S-ml(88<A<140)后,在任何金属丰度下,S-mh和S-ml核素丰度分别与太阳系的相应分布基本相同或相似,因此它们各自的积累结果即各金属丰度的平均分布也与太阳系基本相同或相似,从而太阳系的S-m元素丰度分布具有典型性,可以作为研究各金属丰度下中子俘获元素丰度分布问题的基础.

Study on the S-process Abundance Distribution
ZHANG Feng-hua1,2, LIU Wei-wei1,2, ZHANG Bo2
1. Department of Physics, Cangzhou Normal College, Hebei Cangzhou 061001, China;
2. College of Physics, Hebei Normal University, Hebei Shijiazhuang 050016, China
Abstract:
Using the solution of S-process chain with an exponential neutron irradiation the S-process abundance distribution of AGB stars of different metallicities is investigated.The results show that the S-process production varies as a function of metallicity at low metallicity. However, if separate the main S-process component into two parts, 88< A< 138(S-ml) and 140< A <204(S-mh), the abundance distribution of the S_mh component for the bulk of isotopes 140≤ A ≤204 is strongly similar to the solar S-m pattern at any metallicity, while the abundance distribution of the S_ml component part with A< 140 are nearly similar to the corresponding solar elements abundance distributions. Thus the cumulative consequence of long term Galactic chemical evolution starting from low metallicity AGB stars is of same characteristics. Consequently the solar elements abundance distributions of the two parts are both typical and each can serve as a basis (standard pattern) in investigating the abundance distribution of elements covering all metallicity intervals.

收稿日期: 2002-10-14
基金项目: 国家自然科学基金资助项目(19973002)

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