论文标题
氦白矮人的种群综合 - 红色巨星合并以及富含锂的巨人和碳星的形成
Population synthesis of helium white dwarf--red giant star mergers and the formation of lithium-rich giants and carbon stars
论文作者
论文摘要
尚不清楚富含锂和富含碳的红色巨人的形成历史。已经提出，与红色巨型分支恒星的氦核白矮人合并可能会提供解决方案。我们已经计算了合并后演化模型的扩展网格，并将其与二元星人群合成的预测相结合。结果强烈支持这样的提议，即氦白色矮人与红色巨型分支恒星的合并可以为富含锂富含锂的红色块状星和早期R碳星的祖细胞提供。 The distribution of post-merger models in $T_{\rm eff}$, $\log g$, $\log L$, the surface abundances of lithium and carbon, and the predicted space densities agree well with the observed distributions of these parameters for Li-rich and early-R stars in the Galaxy.
The formation histories of lithium-rich and carbon-rich red giants are not yet understood. It has been proposed that the merger of a helium-core white dwarf with a red giant branch star might provide a solution. We have computed an extended grid of post-merger evolution models and combined these with predictions of binary star population synthesis. The results strongly support the proposal that the merger of a helium white dwarf with a red giant branch star can provide the progenitors of both lithium-rich red clump stars and early-R carbon stars. The distribution of post-merger models in $T_{\rm eff}$, $\log g$, $\log L$, the surface abundances of lithium and carbon, and the predicted space densities agree well with the observed distributions of these parameters for Li-rich and early-R stars in the Galaxy.
