Stellar Collisions and the Interior Structure of Blue Stragglers
Stellar Collisions and the Interior Structure of Blue Stragglers
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DOI：
10.1086/339060
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发表时间：
2001-07
期刊：
影响因子：
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通讯作者：
J. Lombardi, Jr.;Jessica S. Warren;F. Rasio;A. Sills;A. Warren
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文献类型：
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作者：
J. Lombardi, Jr.;Jessica S. Warren;F. Rasio;A. Sills;A. Warren
主序星的碰撞经常发生在密集的星星团中。在疏散星团和球状星团中，这些碰撞产生的合并残留物可以被观测到为蓝离散星。这个过程的详细理论模型需要在三维空间进行冗长的流体动力学计算。然而，一个计算成本较低的方法，我们在这里提出，是近似合并过程（包括冲击加热，流体动力学混合，质量喷射和角动量转移）与简单的算法的基础上守恒定律和基本的定性理解的流体动力学。这些算法已经通过与我们以前的流体动力学模拟的结果进行了微调。我们发现，我们的简单模型的热力学和化学成分的配置文件同意非常好，从最近的SPH（平滑粒子流体动力学）计算的恒星碰撞，和随后的恒星演化我们的简单模型也匹配密切，更准确的流体动力学模型。我们的算法已经在一个易于使用的软件包中实现，我们正在公开提供。该软件可与必须考虑到恒星碰撞的星星团的真实动力学模拟结合使用。
Collisions of main-sequence stars occur frequently in dense star clusters. In open and globular clusters, these collisions produce merger remnants that may be observed as blue stragglers. Detailed theoretical models of this process require lengthy hydrodynamic computations in three dimensions. However, a less computationally expensive approach, which we present here, is to approximate the merger process (including shock heating, hydrodynamic mixing, mass ejection, and angular momentum transfer) with simple algorithms based on conservation laws and a basic qualitative understanding of the hydrodynamics. These algorithms have been fine-tuned through comparisons with the results of our previous hydrodynamic simulations. We find that the thermodynamic and chemical composition profiles of our simple models agree very well with those from recent SPH (smoothed particle hydrodynamics) calculations of stellar collisions, and the subsequent stellar evolution of our simple models also matches closely that of the more accurate hydrodynamic models. Our algorithms have been implemented in an easy-to-use software package, which we are making publicly available. This software could be used in combination with realistic dynamical simulations of star clusters that must take into account stellar collisions.