论文标题
与WD捐赠者的AM CVN二进制文件的演变
Evolution of AM CVn binaries with WD donors
论文作者
论文摘要
CO+He WD二进制的传质的演变和稳定性尚不清楚。从观察上看，它们可能会出现为AM CVN二进制文件，并且是重要的引力波（GW）发射器。在这项工作中，我们已经建模了双WD二进制文件的演变，增生质量为$ 0.50-1.30 \; m _ {\ odot} $，供体群众和$ 0.17 \; -0.45 \; m _ {\ odot} $使用详细的Evolution Code Mesa。我们发现，具有相同供体的二进制物的演变，但不同的增生质量非常相似，并且具有相同增生质量的二进制物，但更大的供体供体质量具有较大的最大质量传递率和较小的最小轨道周期。我们还证明，可以通过太空传播的GW观测值（例如Lisa，Tianqin）检测到来自AM CVN二进制文件的GW信号。在传质阶段，供体质量和重力波频率之间存在线性关系。在我们的计算中，所有二进制文件都可以动态稳定的传质，这与以前的研究大不相同。给定吸积WD质量的Eddington限制质量转移的阈值供体质量低于以前的研究。假设二进制如果批评率超过HE的最大稳定燃烧率，则可以进入共同的包膜，我们为幸存的质量转移的新标准提供了新的标准，该标准低于Eddington-limit的阈值。最后，我们发现我们计算中有一个WD的某些系统可能会演变为由中子星（NSS）和极低的WDS和进一步的超紧凑型X射线二进制组成的分离二进制组。
The evolution and stability of mass transfer of CO+He 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 $0.50 - 1.30\;M_{\odot}$ and donor masses of $0.17\; - 0.45\;M_{\odot}$ 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 space-borne GW observatories, such as LISA, TianQin. And there is a linear relation between the donor mass and gravitational wave frequency during 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 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 Eddington-limit. Finally, we find that some systems with ONe WDs in our calculation may evolve into detached binaries consisting of neutron stars (NSs) and extremely low mass He WDs and further ultra-compact X-ray binaries.
