Post-common envelope binary systems experiencing helium-shell driven stable mass transfer
Post-common envelope binary systems experiencing helium-shell driven stable mass transfer
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DOI：
10.1093/mnras/sty2243
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发表时间：
2018-08
影响因子：
4.8
通讯作者：
Ghina M. Halabi;R. Izzard;C. Tout
中科院分区：
文献类型：
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作者：
Ghina M. Halabi;R. Izzard;C. Tout
我们发展恒星模型来研究初始质量为5M突的早期渐近巨大分支恒星与质量范围为0.1至2M突的伴星之间的共同包络层（CE）相互作用。我们将CE建模为一个快速剥离阶段，在这个阶段，初级质量迅速损失，损失了大约80%的质量。然后在罗氏瓣溢出（RLOF）阶段允许后ce残余进行热调整，并对最终的双星系统及其轨道周期进行了研究。我们发现ce后的RLOF阶段足够长，可以允许核燃烧在氦壳中进行。在这一阶段结束时，供体被剥夺了氢和氦，最终成为质量约为0.8M的碳氧白矮星。我们研究了我们的结果对剥离阶段开始时不同伴星质量和轨道间距初始条件的敏感性。我们发现伴星质量影响最终的双星分离，氦壳燃烧导致恒星重新填充其罗氏叶，导致ce后的RLOF。我们的结果表明，在这样的双星相互作用中，双质量传递能够从供体恒星上剥离氦和氢层，而不需要任何特殊条件或对双星参数进行微调。
We evolve stellar models to study the common envelope (CE) interaction of an early asymptotic giant branch star of initial mass 5Mʘ with a companion star of mass ranging from 0.1 to 2Mʘ. We model the CE as a fast stripping phase in which the primary experiences rapid mass loss and loses about 80 per cent of its mass. The post-CE remnant is then allowed to thermally readjust during a Roche-lobe overflow (RLOF) phase and the final binary system and its orbital period are investigated. We find that the post-CE RLOF phase is long enough to allow nuclear burning to proceed in the helium shell. By the end of this phase, the donor is stripped of both its hydrogen and helium and ends up as carbon-oxygen white dwarf of mass about 0.8Mʘ. We study the sensitivity of our results to initial conditions of different companion masses and orbital separations at which the stripping phase begins. We find that the companion mass affects the final binary separation and that helium-shell burning causes the star to refill its Roche lobe leading to post-CE RLOF. Our results show that double mass transfer in such a binary interaction is able to strip the helium and hydrogen layers from the donor star without the need for any special conditions or fine tuning of the binary parameters.