大样本恒星演化研究组知识库

The neutron-capture process is traditionally postulated to be responsible for the nucleosynthesis of heavy elements beyond Fe. Based on the least 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 metal-poor 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(151) = 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 angstrom line of Sm.