3D models of radiatively driven colliding winds in massive O+O star binaries – I. Hydrodynamics
3D models of radiatively driven colliding winds in massive O+O star binaries – I. Hydrodynamics
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大型 O+O 星双星中辐射驱动碰撞风的 3D 模型 – I. 流体动力学
DOI：
10.1111/j.1365-2966.2009.14857.x
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发表时间：
2009
影响因子：
4.8
通讯作者：
J. Pittard
中科院分区：
文献类型：
--
作者：
J. Pittard
使用 3D 流体动力学模型研究了大质量恒星双星中风-风碰撞的动力学，该模型结合了重力、风的驱动、恒星的轨道运动和冲击等离子体的辐射冷却。在第一篇论文中，我们将研究限制在主序 O+O 双星上。风-风碰撞区域的性质很大程度上取决于激波等离子体的冷却程度以及激波等离子体的流动时间尺度与轨道时间尺度的比率。封闭系统中的预震风速较低，因为风在加速到终端速度之前发生碰撞。辐射抑制也可能降低预震风速。这些效应共同作用可导致震后气体快速冷却。在更广泛的系统中，辐射抑制不太重要，在这些系统中，风在碰撞之前加速到更高的速度，并且产生的碰撞区域在很大程度上是绝热的。在具有偏心轨道的系统中，在近星体通过过程中形成的冷气体甚至可以在近星体处持续存在，然后被消融并混合到周围环境中和/或加速离开系统。
The dynamics of the wind–wind collision in massive stellar binaries are investigated using 3D hydrodynamical models which incorporate gravity, the driving of the winds, the orbital motion of the stars and radiative cooling of the shocked plasma. In this first paper, we restrict our study to main-sequence O+O binaries. The nature of the wind–wind collision region is highly dependent on the degree of cooling of the shocked plasma, and the ratio of the flow time-scale of the shocked plasma to the orbital time-scale. The pre-shock wind speeds are lower in close systems as the winds collide prior to their acceleration to terminal speeds. Radiative inhibition may also reduce the pre-shock wind speeds. Together, these effects can lead to rapid cooling of the post-shock gas. Radiative inhibition is less important in wider systems, where the winds are accelerated to higher speeds before they collide, and the resulting collision region can be largely adiabatic. In systems with eccentric orbits, cold gas formed during periastron passage can persist even at apastron, before being ablated and mixed into its surroundings and/or accelerated out of the system.