All the elements heavier than Fe are produced either by the slow (-s) or rapid (-r) neutron-capture process. The neutron density prevailing in the stellar sites is one of the major factors that determines the type of neutron-capture processes. We present the results based on the estimates of corrected value of absolute carbon abundance, [C/N] ratio, carbon isotopic ratio and [hs/ls] ratio obtained from the high-resolution spectral analysis of six stars that include both CH stars and CEMP stars. All the stars show enhancement of neutron-capture elements. Location of these objects in the A(C) vs. [Fe/H] diagram shows that they are Group I objects, with external origin of carbon and neutron-capture elements. Low values of carbon isotopic ratios estimated for these objects may also be attributed to some external sources. As the carbon isotopic ratio is a good indicator of mixing, we have used the estimates of $$^{12}$$ 12 C/ $$^{13}$$ 13 C ratios to examine the occurrence of mixing in the stars. While the object HD 30443 might have experienced an extra mixing process that usually occurs after red giant branch (RGB) bump for stars with log(L/L $$_{\odot }$$ ⊙ ) > 2.0, the remaining objects do not show any evidence of having undergone any such mixing process. The higher values of [C/N] ratios obtained for these objects also indicate that none of these objects have experienced any strong internal mixing processes. Based on the estimated abundances of carbon and the neutron-capture elements, and the abundance ratios, we have classified the objects into different groups. While the objects HE 0110−0406, HD 30443 and CD−38 2151 are found to be CEMP-s stars, HE 0308−1612 and HD 176021 show characteristic properties of CH stars with moderate enhancement of carbon. The object CD−28 1082 with enhancement of both r- and s-process elements is found to belong to the CEMP-r/s group.

中文翻译：

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CH 和碳增强贫金属 (CEMP) 星中中子俘获元素的丰度

所有比 Fe 重的元素都是通过慢 (-s) 或快 (-r) 中子俘获过程产生的。恒星位置的中子密度是决定中子俘获过程类型的主要因素之一。我们根据从包括 CH 星和 CH 星的高分辨率光谱分析中获得的绝对碳丰度、[C/N] 比、碳同位素比和 [hs/ls] 比的校正值的估计值来介绍结果。 CEMP 星星。所有的恒星都显示出中子俘获元素的增强。这些物体在 A(C) vs. [Fe/H] 图中的位置表明它们是 I 组物体，具有外部来源的碳和中子俘获元素。为这些天体估算的碳同位素比值偏低也可能归因于某些外部来源。由于碳同位素比率是混合的一个很好的指标，我们使用 $$^{12}$$ 12 C/ $$^{13}$$ 13 C 比率的估计值来检查恒星中混合的发生。虽然物体 HD 30443 可能经历了一个额外的混合过程，通常发生在 log(L/L $$_{\odot }$$⊙ ) > 2.0 的恒星的红巨星分支 (RGB) 碰撞之后，其余的物体没有显示任何经历过任何此类混合过程的证据。为这些物体获得的较高的 [C/N] 比值也表明这些物体都没有经历过任何强烈的内部混合过程。根据碳和中子俘获元素的估计丰度以及丰度比，我们将物体分为不同的组。虽然发现对象 HE 0110−0406、HD 30443 和 CD−38 2151 是 CEMP-s 恒星，HE 0308−1612 和 HD 176021 显示出具有中等碳增强的 CH 星的特征。发现具有增强的 r 和 s 过程元素的对象 CD-28 1082 属于 CEMP-r/s 组。