THE TRANSITION MASS-LOSS RATE: CALIBRATING THE ROLE OF LINE-DRIVEN WINDS IN MASSIVE STAR EVOLUTION
THE TRANSITION MASS-LOSS RATE: CALIBRATING THE ROLE OF LINE-DRIVEN WINDS IN MASSIVE STAR EVOLUTION
复制标题
转变质量损失率：校准线驱动风在大质量恒星演化中的作用
DOI：
10.1088/2041-8205/751/2/l34
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
G. Gräfener
中科院分区：
文献类型：
--
作者：
J. Vink;G. Gräfener
关于大质量星星演化中静止质量损失与爆发质量损失的重要性，出现了一场争论。原因是恒星风被发现是成团的，这导致了非成团的经验质量损失率的降低。大多数恒星演化模型采用的理论质量损失率与未经修正的经验损失率相比，已经降低了2.2 -3倍。一个关键的问题是，这些降低的速率是否处于正确的数量级，或者它们是否应该进一步降低，这意味着爆发性质量损失的替代方案变得必要。在这里，我们介绍过渡质量损失率之间的O和沃尔夫-拉叶星。它的新奇在于它是模型独立的。所有这一切都需要在一个给定的数据集假设光谱转换点，并确定恒星的光度，这是远远低于模型依赖的质量损失率。过渡质量损失率随后被用来校准恒星风的强度，其应用程序的Of/WNh星的拱门集群。良好的协议被发现与两个替代的建模/理论结果，这表明目前的理论模型提供的速率是正确的数量级在150 M的质量范围。我们的研究结果并没有证实爆发的质量损失作为明亮的蓝色变量的具体需要，目前银河系大质量恒星的恒星演化模型似乎合理。通过替代机制的质量损失在较低的质量和/或金属含量下可能仍然是必要的，并且替代质量损失的量化是可取的。
A debate has arisen regarding the importance of stationary versus eruptive mass loss for massive star evolution. The reason is that stellar winds have been found to be clumped, which results in the reduction of unclumped empirical mass-loss rates. Most stellar evolution models employ theoretical mass-loss rates which are already reduced by a moderate factor of ≃2–3 compared to non-corrected empirical rates. A key question is whether these reduced rates are of the correct order of magnitude, or if they should be reduced even further, which would mean that the alternative of eruptive mass loss becomes necessary. Here we introduce the transition mass-loss rate between O and Wolf–Rayet stars. Its novelty is that it is model independent. All that is required is postulating the spectroscopic transition point in a given data set, and determining the stellar luminosity, which is far less model dependent than the mass-loss rate. The transition mass-loss rate is subsequently used to calibrate stellar wind strength by its application to the Of/WNh stars in the Arches cluster. Good agreement is found with two alternative modeling/theoretical results, suggesting that the rates provided by current theoretical models are of the right order of magnitude in the ∼50 M☉ mass range. Our results do not confirm the specific need for eruptive mass loss as luminous blue variables, and current stellar evolution modeling for Galactic massive stars seems sound. Mass loss through alternative mechanisms might still become necessary at lower masses, and/or metallicities, and the quantification of alternative mass loss is desirable.