arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新，休息一下吧，周末愉快~~
arXiv 0910.0522astro-ph.SR
收藏

进入公共信封阶段之前旋转信封

Spinning-Up the Envelope Before Entering a Common Envelope Phase

Ealeal Bear, Noam Soker

备注：
New Astronomy, in press
发表信息：
New Astron.15:483-490,2010
阅读 PDF
arXiv 页面 ↗HTML 原文 ↗

摘要：

我们计算了双星系统的轨道演化，其中主星是一个演化的红巨星分支（RGB）的明星，而次要的明星是一个低质量的主序星（MS）或棕矮星。演化开始于潮汐相互作用，导致次级螺旋进入。然后，在非常短的时间内形成公共包络（CE），或者可选地，系统达到同步并且螺旋进入过程显著减慢。后者的一些系统后来进入CE阶段。我们发现，对于一个大范围的系统参数，二进制系统达到稳定的同步轨道的CE阶段开始之前。这种稳定的同步轨道允许RGB星在CE阶段开始之前失去质量。即使在次级恒星进入巨行星包层之后，其旋转速度也足够高，从而导致质量损失率的增加。我们的研究结果意味着，它是至关重要的，包括前CE的演变时，研究CE阶段的结果。我们发现，更多的系统生存的CE阶段比将是这种情况下，如果这些先前的自旋和质量损失阶段没有被考虑在内。虽然我们已经对RGB恒星进行了计算，但结果对其他与亲密同伴相互作用的演化恒星具有影响。

英文摘要：

We calculate the orbital evolution of binary systems where the primary star is an evolved red giant branch (RGB) star, while the secondary star is a low-mass main sequence (MS) star or a brown dwarf. The evolution starts with a tidal interaction causes the secondary to spiral-in. Than either a common envelope (CE) is formed in a very short time, or alternatively the system reaches synchronization and the spiraling-in process substantially slows down. Some of the latter systems later enter a CE phase. We find that for a large range of system parameters, binary systems reach stable synchronized orbits before the onset of a CE phase. Such stable synchronized orbits allow the RGB star to lose mass prior to the onset of the CE phase. Even after the secondary enters the giant envelope, the rotational velocity is high enough to cause an enhanced mass-loss rate. Our results imply that it is crucial to include the pre-CE evolution when studying the outcome of the CE phase. We find that many more systems survive the CE phase than would be the case if these preceding spin-up and mass-loss phases had not been taken into account. Although we have made the calculations for RGB stars, the results have implications for other evolved stars that interact with close companions.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

↑