A common-envelope wind model for Type Ia supernovae – I. Binary evolution and birth rate
A common-envelope wind model for Type Ia supernovae – I. Binary evolution and birth rate
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DOI：
10.1093/mnras/stx1137
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发表时间：
2017-05
影响因子：
4.8
通讯作者：
X. Meng;P. Podsiadlowski
中科院分区：
文献类型：
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作者：
X. Meng;P. Podsiadlowski
单简并（SD）模型是Ia型超新星（SNe Ia）的主要模型之一，但在SD模型中研究最广泛的版本，即光学厚风（OTW）模型中的一些预测尚未得到观测的证实。在这里，我们提出了一个新版本的SD模型，其中一个共同的信封（CE）被假定为形成时，碳氧白色矮星（CO WD）和它的同伴之间的质量传递速率超过一个临界吸积率。WD可以在CE的基部逐渐增加其质量。由于稳定的氢燃烧所需的大的核光度，CE可能会膨胀到巨大的尺寸，并会在CE风（CEW）的作用下从CE表面失去质量。由于低CE密度，二元系统将避免快速螺旋进入阶段，并最终从CE阶段重新出现。我们的模式可能具有OTW模式的优点，但避免了它的一些缺点。我们对1100多个近距离WD + MS双星进行了双星演化计算。与OTW模型相比，CEW模型中Ia超新星的参数空间扩展到了质量更大的伴星和质量更小的WDs。相应地，CEW模型得出的银河系出生率比OTW模型得出的要高出30%。最后，我们讨论了CEW模型的不确定性以及我们的CEW模型与OTW模型的区别。
The single-degenerate (SD) model is one of the principal models for the progenitors of type Ia supernovae (SNe Ia), but some of the predictions in the most widely studied version of the SD model, i.e. the optically thick wind (OTW) model, have not been confirmed by observations. Here, we propose a new version of the SD model in which a common envelope (CE) is assumed to form when the mass-transfer rate between a carbon-oxygen white dwarf (CO WD) and its companion exceeds a critical accretion rate. The WD may gradually increase its mass at the base of the CE. Due to the large nuclear luminosity for stable hydrogen burning, the CE may expand to giant dimensions and will lose mass from the surface of the CE by a CE wind (CEW). Because of the low CE density, the binary system will avoid a fast spiral-in phase and finally re-emerge from the CE phase. Our model may share the virtues of the OTW model but avoid some of its shortcomings. We performed binary stellar evolution calculations for more than 1100 close WD + MS binaries. Compared with the OTW model, the parameter space for SNe Ia from our CEW model extends to more massive companions and less massive WDs. Correspondingly, the Galactic birth rate from the CEW model is higher than that from the OTW model by $\sim$30\%. Finally, we discuss the uncertainties of the CEW model and the differences between our CEW model and the OTW model.