星系晕较重r-过程元素产量和丰度的离散  

The Heavy R-process Elements Yields and Abundances Scatter in the Halo of Galaxy

作　　者：周晓静[1] 张波[2] 

机构地区：[1]邯郸学院物理与电气工程系,河北邯郸056005 [2]河北师范大学物理科学与信息工程学院,河北石家庄050016

出　　处：《河北师范大学学报（自然科学版）》2009年第4期473-481,共9页Journal of Hebei Normal University：Natural Science

基　　金：国家自然科学基金(10673002)

摘　　要：采用Fields等所提出的模型,将超新星爆发产生r-过程元素的事件分为2类:A类(r-rich)事件和B类(r-poor)事件,结合所得到的Ⅱ型超新星r-过程元素的产量和产区,计算了贫金属星较重r-过程元素的弥散,并与观测进行对比分析,解释早期星系化学演化.得到的主要结论:从星系化学演化角度看,星系r-过程元素主要来源于大质量星,r-过程核合成主要产生场所是较高质量的Ⅱ型超新星,质量范围在28M⊙≤M≤35M⊙.利用计算得到的产量及初始质量函数φ(m),确定产生较重r-过程元素的Ⅱ型超新星占Ⅱ型超新星总数的比例(大约为4%),计算得到星系晕中Eu,Ba,Ce,La,Nd,Pr,Sm等元素的丰度离散情况;并对计算结果进行分析.Adopting the classification of Fields 2002, the supernovae event with larger r/Fe ratio was classified as class A（r-rich event） and those with the lower ratio class B（r-poor event）. Based on the calculation of yields and productive mass range of this paper, the abundance scatter of the heavy r-process elements was calcu- lated and the results were compared with the observation. The conclusions obtained were as follows： There was a producing peak of various supernova（28M⊙ M〈 35M⊙）for the r-process element yields. Thus, massive stars （i. e. 28M⊙ 〈 M〈 35M⊙ ） were the primary sites of the r-process nucleosynthesis. The supernovaes which produced heavy r-process elements originated from a small fraction about 4 % of all Type Ⅱ supernovae stars.

关 键 词：Ⅱ型超新星 r-过程 产量 核合成主要场所 丰度离散 元素星系化学演化 

分 类 号：P142.9[天文地球—天体物理]