论文标题
Betelgeuse项目III：合并特征
The Betelgeuse Project III: Merger Characteristics
论文作者
论文摘要
我们以前提出，Betelgeuse可能是通过积聚约1个太阳能量的同伴来启动的。在这里，我们更详细地探索了这种合并和更大范围的积聚质量的系统。我们使用恒星进化代码MESA在核心氦气燃烧，核心碳燃烧或壳碳燃烧中为初级恒星增添角度动量。我们的模型提供了一个合理的“自然”解释，说明了为什么Betelgeuse具有较大但次言的赤道速度。它们在旋转诱导的质量损失中排出足够的质量和角动量，以重现赤道速度的观察到的比率，避免了betelgeuse的避免速度，〜0.23，在三个几乎独立于初级质量，次生质量的次数之内，次要质量和时代发生了。我们的模型表明，在核心氦燃烧或核心碳燃烧期间，少于15个太阳能的初级合并少于1到10个太阳能，可能会产生约15 km/s的赤道旋转速度，归因于贝特尔盖塞（Betelgeuse）。对于积聚模型，在氦芯边缘的组成边界上停止了一波角动量。因此，在这些模拟中，内核不受同伴的积聚的影响。积聚对内核中磁场的产生的影响相对较小。我们的结果并未证明，但不要否定贝特尔格内斯可能已经摄入了几个太阳能的伴侣。
We previously proposed that Betelgeuse might have been spun up by accreting a companion of about 1 solar mass. Here we explore in more detail the possible systematics of such a merger and a larger range of accreted masses. We use the stellar evolutionary code MESA to add angular momentum to a primary star in core helium burning, core carbon burning, or shell carbon burning. Our models provide a reasonable "natural" explanation for why Betelgeuse has a large, but sub-Keplerian equatorial velocity. They eject sufficient mass and angular momentum in rotationally-induced mass loss to reproduce the observed ratio of the equatorial velocity to escape velocity of Betelgeuse, ~0.23, within a factor of three nearly independent of the primary mass, the secondary mass, and the epoch at which merger occurs. Our models suggest that merger of a primary of somewhat less than 15 solar masses with secondaries of from 1 to 10 solar masses during core helium burning or core carbon burning could yield the equatorial rotational velocity of ~15 km/s attributed to Betelgeuse. For accreting models, a wave of angular momentum is halted at the composition boundary at the edge of the helium core. The inner core is thus not affected by the accretion of the companion in these simulations. Accretion has relatively little effect on the production of magnetic fields in the inner core. Our results do not prove, but do not negate that Betelgeuse might have ingested a companion of several solar masses.
