Wind accretion in binary stars I. Mass accretion ratio
Wind accretion in binary stars I. Mass accretion ratio
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双星中的风吸积 I. 质量吸积比
DOI：
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
Daniel I. C. Wang
中科院分区：
文献类型：
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作者：
M. Croughan;J. Hamel;Daniel I. C. Wang
进行三维流体动力学计算是为了研究封闭二元系统中的质量传递，其中一个组件因风而遭受质量损失。假设质量比是统一的。质量损失恒星的半径约为两颗恒星之间距离的四分之一。对比热比 γ = 1.01 和 5/3 的气体进行计算。假设质量损失是热驱动的，因此另一个参数是质量损失恒星上气体的声速。在这里，我们将注意力集中在两个特征上：流动模式和质量吸积比，我们将其定义为伴星 u Macc 上的质量吸积率与质量损失主星 u Mloss 的质量损失率之比。我们通过质量损失恒星 VR 临界罗希表面上的风的平均法向速度来表征流动。当 VR 为 0.7 AΩ 时，我们观察到风吸积。我们发现这两种极端情况之间的流动模式非常复杂。我们推导出质量吸积比的经验公式，在低速区域为 0.18 × 10 -0.75VR /AΩ，在高速区域为 0.05 (VR/AΩ) -4。
Three-dimensional hydrodynamic calculations are performed in order to investigate mass transfer in a close binary system, in which one component undergoes mass loss through a wind. The mass ratio is assumed to be unity. The radius of the mass-losing star is taken to be about a quarter of the separation between the two stars. Calculations are performed for gases with a ratio of specific heats γ = 1.01 and 5/3. Mass loss is assumed to be thermally driven so that the other parameter is the sound speed of the gas on the mass-losing star. Here, we focus our attention on two features: flow patterns and mass accretion ratio, which we define as the ratio of the mass accretion rate onto the companion, u Macc, to the mass loss rate from the mass-losing primary star, u Mloss. We characterize the flow by the mean normal velocity of the wind on the critical Roche surface of the mass-losing star, VR .W henVR 0.7 AΩ we observe wind accretion. We find very complex flow patterns in between these two extreme cases. We derive an empirical formula of the mass accretion ratio as 0.18 × 10 −0.75VR /AΩ in the low velocity regime and 0.05 (VR/AΩ) −4 in the high velocity regime.