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arXiv · 1801.07919

The odd-isotope fractions of Barium in the strongly r-process enhanced (r-II) stars

Wenyuan Cui·Xiaohua Jiang·Jianrong Shi·Gang Zhao·Bo Zhang
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Abstract

We determined the \fodd\ values, $0.46\pm0.08$, $0.51\pm0.09$, $0.50\pm0.13$, $0.48\pm0.12$, which correspond to the r-contribution 100\% for four r-II stars, \cs, \hen, \hes\, and \het, respectively. Our results suggest that almost all of the heavy elements (in the range from Ba to Pb) in r-II stars have a common origin, that is, from a single r-process (the main r-process). We found that the \fodd\ has a intrinsic nature, and should keep constant value of about 0.46 in the main r-process yields, which is responsible for the heavy element enhancement of r-II stars and of our Galaxy chemical enhancement. In addition, except the abundance ratio [Ba/Eu] the \fodd\ is also an important indicator, which can be used to study the relative contributions of the r- and s-process during the chemical evolution history of the Milky Way and the enhancement mechanism in stars with peculiar abundance of heavy elements.

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Wenyuan Cui, Xiaohua Jiang, Jianrong Shi, Gang Zhao, Bo Zhang. 2018-01-24. The odd-isotope fractions of Barium in the strongly r-process enhanced (r-II) stars. https://arxiv.org/abs/1801.07919

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