摘要
The neutron-capture process is traditionally postulated to be responsible for the nucleosynthesis of heavy elements beyond Fe.Based on theleast squares method and solar isotopic abundances from the classical model,we estimate the relative contributions of the s- and r-processes to the abundance of neutron-capture elements in the metalpoor star HD 175305 from the component coefficients.Applying the calculated component coefficients C_(r) and C_(s),the model predicts the isotopic fractions of elements Nd,Sm and Eu to be f_(142+144) =0.482,f_(152+154) =0.525 and f_(l51) =0.450,respectively.As well as the observed abundances,the isotropic fractions are also consistent with the calculations.Finally,for the first time,we estimated the contribution percentage of the two neutron processes (the r- and s-processes) from the observed isotopic fractions of different elements in HD 175305,e.g.an r-process contribution of 67%^(+21%)_(-32%) from the 4604 (A) line of Sm.
作者
ZHANG Jiang
WANG Bo
ZHANG Bo
HAN Zhan-Wen
张江;王博;张波;韩占文(National Astronomical Observatories/Yunnan Observatory,Chinese Academy of Sciences,Kunming 650011;Key Laboratory for the Structure and Evolution of Celestial Objects,Chinese Academy of Sciences,Kunming 650011;School of Mathematics and Science,Shijiazhuang University of Economics,Shijiazhuang 050016;Department of Physics,Hebei Normal University,Shijiazhuang 050016)
基金
Supported by the National Natural Science Foundation of China under Grant Nos 10973006,10821061,11033008,11103072,10973036 and 11003002
the National Basic Research Program of China under Grant No 2009CB824800
the Knowledge Innovation Program of the Chinese Academy of Sciences under Grant No KJCX2-YW-T24.