相互作用后白矮星-主序星双星的种群统计学：从共包层演化到稳定质量转移
Population demographics of post-interaction WDMS binaries: From common envelope evolution to stable mass transfer
浏览论文内容
中文总结 AI 辅助
研究紧密白矮星-主序星双星种群统计学，通过对三个观测样本同时前向建模，约束双星演化参数，发现AGB与RGB供体质量转移临界比及共包层效率，多数产物有非零偏心率，模型未完全再现主序星质量分布，指出未来需探索缺失物理机制。
中文摘要 AI 辅助
紧密的白矮星（WD）+主序星（MS）双星是WD前身星为巨星时发生质量转移（MT）的最终产物，其种群统计学是双星演化的有力探测手段。近期一些研究利用广域巡天数据构建了具有明确选择函数的WD+MS双星样本，包括基于盖亚数据的天文测量双星、通过GALEX紫外过剩检测到热WD的天文测量双星以及通过食相发现的紧密双星。这些样本探测了稳定MT和共包层演化的结果以及红巨星分支（RGB）和渐近巨星分支（AGB）上的相互作用。我们同时对这三个观测样本进行前向建模，该方法对不确定的双星演化参数产生了有力约束。我们的建模包括现实的初始双星种群和对影响所有样本的选择效应的处理。我们发现，来自AGB供体的MT需要临界吸积体与供体质量比约为0.4，并且比来自RGB供体的MT更稳定，后者临界比约为0.65。共包层效率αλ约为0.3与紧密和宽系统的相对数量以及紧密系统的周期分布相匹配。样本中大多数稳定MT产物，包括那些具有RGB供体的产物，保留非零偏心率（约为0.1）。该模型不能完全再现共包层后双星中主序星的质量分布，其在远低于完全对流极限处呈现一个悬崖，这表明未来工作应探索缺失的物理机制。
英文摘要
Close white dwarf (WD) + main-sequence (MS) binaries are end products of mass transfer (MT) that occurred prior to WD formation, making their population demographics a powerful probe of binary evolution. Several recent works have constructed samples of WD+MS binaries with well-understood selection functions using data from wide-field surveys. These include (a) AU-scale astrometric binaries from Gaia that can be shown to contain a WD on dynamical grounds, (b) AU-scale astrometric binaries in which a hot WD is detected through a GALEX UV excess, and (c) close binaries discovered through eclipses. Together, these samples probe outcomes of both stable MT and common-envelope evolution, and interactions on both the red giant branch (RGB) and asymptotic giant branch (AGB). We forward model the three observed samples simultaneously. This approach produces robust constraints on uncertain binary evolution parameters because binaries removed from one population are predicted to appear in another. Our modeling includes a realistic initial binary population and treatments of the selection effects affecting all samples. We confirm that MT from AGB donors requires a critical accretor-to-donor mass ratio of $\sim0.4$ as found in previous work, and find that this is more stable than MT from RGB donors, for which we constrain a critical ratio $\gtrsim0.65$. A common envelope efficiency of $αλ\sim0.3$ matches the relative numbers of close and wide systems and the period distribution of close systems. Most stable MT products in the sample, including those with RGB donors, retain nonzero eccentricities ($\simeq0.1$). The model does not fully reproduce the mass distribution of main-sequence stars in post-common envelope binaries, which shows a cliff below the fully convective limit, possibly pointing to missing physics that may warrant future work.
发表机构
- California Institute of Technology（加州理工学院）
机构由 AI 辅助整理，请以论文原文为准。
