论文标题
与渐近巨型分支星星的共同环
Common-envelope evolution with an asymptotic giant branch star
论文作者
论文摘要
共同嵌入式阶段对于许多二元系统的演变是决定性的。特别令人感兴趣的是渐近巨型分支（AGB）主要恒星的病例，因为它们被认为是各种天体物理瞬变的祖细胞。在带有移动网格代码的三维流体动力学模拟中，我们研究了$ 1.0 \，m _ {\ odot} $早期 - 阿格布星的共同 - 固定型演变，与不同的群众同伴。尽管AGB恒星的恒星包膜比红色巨人的结合不太紧密，但我们发现核心二元的轨道能量释放不足以弹出超过百分之二十的信封质量。但是，在扩展的包膜中释放的电离能可以导致完整的包膜弹射。由于重组在我们的模拟中很大程度上进行了光学深度，因此这种效应确实在考虑的系统中确实起着重要作用。质量损失的效率和核心二进制系统的最终轨道分离取决于伴侣和主要恒星之间的质量比。我们的结果表明，最终轨道分离与此参数的比率之间存在线性关系。
Common-envelope phases are decisive for the evolution of many binary systems. Of particular interest are cases with asymptotic giant branch (AGB) primary stars, because they are thought to be progenitors of various astrophysical transients. In three-dimensional hydrodynamic simulations with the moving-mesh code AREPO, we study the common-envelope evolution of a $1.0\,M_{\odot}$ early-AGB star with companions of different masses. Although the stellar envelope of the AGB star is less tightly bound than that of a red giant, we find that the release of orbital energy of the core binary is insufficient to eject more than about twenty percent of the envelope mass. Ionization energy released in the expanding envelope, however, can lead to complete envelope ejection. Because recombination proceeds largely at high optical depths in our simulations, it is likely that this effect indeed plays a significant role in the considered systems. The efficiency of mass loss and the final orbital separation of the core binary system depend on the mass ratio between the companion and the primary star. Our results suggest a linear relation between the ratio of final to initial orbital separation and this parameter.
