Red giant stellar collisions in the Galactic Centre
Red giant stellar collisions in the Galactic Centre
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DOI：
10.1111/j.1365-2966.2008.14254.x
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发表时间：
2008-11
影响因子：
4.8
通讯作者：
J. Dale;M. Davies;R. Church;M. Freitag
中科院分区：
文献类型：
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作者：
J. Dale;M. Davies;R. Church;M. Freitag
我们表明，与恒星质量黑洞的碰撞可以部分解释银河系中心没有明亮的巨星，首先注意到由Genzel等人。我们表明，失踪的对象是低质量的巨人和渐近巨星分支星的范围1-3 M-圆点。使用详细的恒星演化计算，我们发现，以防止这些对象的演变成为可见的耗尽K波段，我们要求他们遭受碰撞的红巨星分支，我们计算所需的分数包络质量损失。使用平滑粒子流体动力学计算，限制性三体分析和蒙特卡罗模拟相结合，我们计算预期的碰撞率之间的巨人和黑洞，巨人和主序星之间的银河系中心。我们发现碰撞可以合理地解释10.5 < K < 12带中缺失的巨星。然而，将较亮的（K < 10.5）天体消耗到所需的半径将需要大量的黑洞撞击物，这反过来又会消耗比观察到的更大区域中的10.5 < K < 12巨星。我们的结论是，与恒星质量黑洞的碰撞不能解释最亮的巨星的耗尽，我们使用我们的结果来限制银河系中心恒星质量黑洞的数量。
We show that collisions with stellar-mass black holes can partially explain the absence of bright giant stars in the Galactic Centre, first noted by Genzel et al. We show that the missing objects are low-mass giants and asymptotic giant branch stars in the range 1-3 M-circle dot. Using detailed stellar evolution calculations, we find that to prevent these objects from evolving to become visible in the depleted K bands, we require that they suffer collisions on the red giant branch, and we calculate the fractional envelope mass losses required. Using a combination of smoothed particle hydrodynamic calculations, restricted three-body analysis and Monte Carlo simulations, we compute the expected collision rates between giants and black holes, and between giants and main-sequence stars in the Galactic Centre. We show that collisions can plausibly explain the missing giants in the 10.5 < K < 12 band. However, depleting the brighter (K < 10.5) objects out to the required radius would require a large population of black hole impactors which would in turn deplete the 10.5 < K < 12 giants in a region much larger than is observed. We conclude that collisions with stellar-mass black holes cannot account for the depletion of the very brightest giants, and we use our results to place limits on the population of stellar-mass black holes in the Galactic Centre.