Evolution of AM CVn Binaries with White Dwarf Donors
Evolution of AM CVn Binaries with White Dwarf Donors
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AM CVn 双星与白矮星供体的演化
DOI：
10.3847/1538-4357/ac7fec
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发表时间：
2022
期刊：
影响因子：
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通讯作者：
Zhanwen Han
中科院分区：
文献类型：
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作者：
Chen Hai-Liang;Chen Xuefei;Zhanwen Han
摘要CO+He白色矮星（WD）双星的演化和质量传递的稳定性还不清楚。在观测上，它们可能以AM CVn双星的形式出现，并且是重要的引力波（GW）发射体。在这项工作中，我们已经模拟了双WD双星的演化与吸积质量为0.50-1.30 M <$A和施主质量为0.17-0.45 M <$A使用详细的恒星演化代码梅萨。我们发现，具有相同施主质量但不同吸积体质量的双星的演化非常相似，具有相同吸积体质量但较大He施主质量的双星具有较大的最大质量传递速率和较小的最小轨道周期。我们还证明了来自AMCVn双星的GW信号可以被星载GW观测站（如丽莎和天琴）检测到。在传质阶段，施主质量与引力波频率之间存在线性关系。在我们的计算中，所有的双星可以有动态稳定的质量传递，这是非常不同于以往的研究。对于给定的吸积体WD质量，Eddington限制质量转移的阈值施主质量低于以前的研究。假设一个二进制可能进入一个共同的信封，如果传质速率超过最大稳定燃烧速率的他，我们提供了一个新的标准双WD幸存的传质，这是低于阈值的爱丁顿限制。最后，我们发现在我们的计算中，一些系统的氧氖（ONe）WD可能会演变成分离的双星组成的中子星和极低质量的He WD，进一步超紧凑的X射线双星。
Abstract The evolution and the stability of mass transfer of CO+He white dwarf (WD) binaries are not well understood. Observationally they may emerge as AM CVn binaries and are important gravitational wave (GW) emitters. In this work, we have modeled the evolution of double WD binaries with accretor masses of 0.50–1.30 M ⊙ and donor masses of 0.17–0.45 M ⊙ using the detailed stellar evolution code mesa . We find that the evolution of binaries with same donor masses but different accretor masses is very similar and binaries with same accretor masses but larger He donor masses have larger maximum mass transfer rates and smaller minimum orbital periods. We also demonstrate that the GW signal from AM CVn binaries can be detected by spaceborne GW observatories, such as LISA and TianQin. There is a linear relation between the donor mass and gravitational wave frequency during the mass transfer phase. In our calculation, all binaries can have dynamically stable mass transfer, which is very different from previous studies. The threshold donor mass of Eddington-limited mass transfer for a given accretor WD mass is lower than previous studies. Assuming that a binary may enter a common envelope if the mass transfer rate exceeds the maximum stable burning rate of He, we provide a new criterion for double WDs surviving mass transfer, which is below the threshold of the Eddington limit. Finally, we find that some systems with oxygen–neon (ONe) WDs in our calculation may evolve into detached binaries consisting of neutron stars and extremely low-mass He WDs, and further ultracompact X-ray binaries.