arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1608.03041astro-ph.SR
收藏

潮汐对相互作用双星中PN粒子数的影响

The Effect of Tides on the Population of PN from Interacting Binaries

Niyas Madappatt, Orsola De Marco, Eva Villaver

摘要:

我们用Zahn的潮汐方程来确定当主星在巨星阶段膨胀时,伴星与它们的巨主星进入洛希瓣接触的最大轨道距离。这是确定巨星与其同伴之间相互作用速率的关键一步。我们的恒星结构计算的最大半径期间达到的红色和渐近巨星分支(RGB和AGB,分别)的质量在0.8和4.0 Mo(Z=0.001 - 0.04)之间的演化阶段,并与其他模型相比,以衡量这些计算的细节得出的半径的不确定性。我们发现整体潮汐捕获距离通常是1-4倍的最大径向范围的巨星,其中同伴的质量范围从1木星质量的质量略小于质量的主要。我们发现,只有在初始轨道间距为~320和~630 Ro之间的同伴通常会被捕获到罗氏叶填充相互作用或AGB上的共同包络。比较这些限制与周期分布的双星,将使PN,我们推断,在标准的情况下,所有~1-8 Mo星,使PN,最多2.5%的所有PN应该有一个共同的信封后中心星双星,与观察到的15%-20%的下限不一致。在考虑不确定性的情况下,PN的相互作用中心星不容易解释。我们研究了一系列解释这种差异。

英文摘要:

We have used the tidal equations of Zahn to determine the maximum orbital distance at which companions are brought into Roche lobe contact with their giant primary, when the primary expands during the giant phases. This is a key step when determining the rates of interaction between giants and their companions. Our stellar structure calculations are presented as maximum radii reached during the red and asymptotic giant branch (RGB and AGB, respectively) stages of evolution for masses between 0.8 and 4.0 Mo (Z=0.001 - 0.04) and compared with other models to gauge the uncertainty on radii deriving from details of these calculations. We find overall tidal capture distances that are typically 1-4 times the maximum radial extent of the giant star, where companions are in the mass range from 1 Jupiter mass to a mass slightly smaller than the mass of the primary. We find that only companions at initial orbital separations between ~320 and ~630 Ro will be typically captured into a Roche lobe-filling interaction or a common envelope on the AGB. Comparing these limits with the period distribution for binaries that will make PN, we deduce that in the standard scenario where all ~1-8 Mo stars make a PN, at most 2.5 per cent of all PN should have a post-common envelope central star binary, at odds with the observational lower limit of 15-20 per cent. The observed over-abundance of post-interaction central stars of PN cannot be easily explained considering the uncertainties. We examine a range of explanations for this discrepancy.

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。

↑