Publications of the Astronomical Society of Australia | |
Co-Production of Light p-, s- and r-Process Isotopes in the High-Entropy Wind of Type II Supernovae | |
K. Farouqi1  | |
[1] K.-L. Kratz | |
关键词: nuclear reactions; nucleosynthesis; abundances; stars: winds; outflows; supernovae: general; | |
DOI : 10.1071/AS08075 | |
学科分类:天文学(综合) | |
来源: CSIRO | |
【 摘 要 】
We have performed large-scale nucleosynthesis calculations within the high-entropy-wind (HEW) scenario of Type II supernovae. The primary aim was to constrain the conditions for the production of the classical ‘p-only’ isotopes of the light trans-Fe elements. We find, however, that for electron fractions in the range 0.458 ≤ Ye ≤ 0.478, sizeable abundances of p-, s- and r-process nuclei between 64Zn and 98Ru are coproduced in the HEW at low entropies (S ≤ 100) by a primary charged-particle process after an α-rich freezeout. With the above Ye–S correlation, most of the predicted isotopic abundance ratios within a given element, e.g. 64Zn(p)/70Zn(r) or 92Mo(p)/94Mo(p), as well as of neighboring elements, e.g. 70Ge(s + p)/74Se(p) or 74Se(p)/78Kr(p) agree with the observed Solar-System ratios. Taking the Mo isotopic chain as a particularly challenging example, we show that our HEW model can account for the production of all 7 stable isotopes, from ‘p-only’ 92Mo, via ‘s-only’ 96Mo up to ‘r-only’ 100Mo. Furthermore, our model is able to reproduce the isotopic composition of Mo in presolar SiC X-grains.
【 授权许可】
Unknown
【 预 览 】
Files | Size | Format | View |
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RO201912040531988ZK.pdf | 260KB | download |