标题： 一个Be星+氦星双星作为双星质量转移阶段的指示器 显示英文标题

标题： A Be Star + He Star Binary as an Indicator of a Binary Mass Transfer Phase

摘要： Be星的快速旋转被认为主要起源于双星演化。 近年来，越来越多的具有氦星（He星）伴星的Be星被发现，这为研究双星相互作用物理提供了重要机会。 在本工作中，我们使用更新的双星质量转移稳定性准则进行双星种群合成，并通过构建一系列Be星+He星（BeHe）双星种群来理解质量转移过程的细节。 我们发现，模拟结果和观测数据可以根据组分的质量分为两组，对应于质量转移期间两种不同的演化过程。 特别是，我们发现BeHe双星的质量比可以作为原始双星初始质量比的探测工具。 此外，结果表明，更高的质量转移效率（$\gtrsim 0.5$）更能支持观测结果。 模拟预测了太多经历Case B质量转移的Be星双星，这与观测结果冲突。 原因是由于观测选择效应或不清楚的物理因素。 显示英文摘要

摘要： The rapid rotation of Be stars is supposed to mainly originate from binary evolution. In recent years, more and more Be stars with helium (He) star companions have been discovered, which provides a significant opportunity to study binary interaction physics. In this work, we perform binary population synthesis with an updated binary mass transfer stability criterion and try to understand the details of mass transfer processes by constructing a series of Be star + He star (BeHe) binary populations. We found that the simulations and the observations can be divided into two groups according to the masses of components, corresponding to the two distinct evolutionary processes during the mass transfer. In particular, we found that the mass ratios of BeHe binaries may be taken as a probe of the initial mass ratios of the primordial binaries. Moreover, the results suggest that a higher mass transfer efficiency ($\gtrsim 0.5$) supports the observations better. The simulations predicted too many Be star binaries experiencing Case B mass transfer, which conflicts with the observations. The reason is due to either observational selection effects or unclear physical factors.