The evolution of wide binary stars
The evolution of wide binary stars
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DOI：
10.1111/j.1365-2966.2009.15744.x
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发表时间：
2009-07
影响因子：
4.8
通讯作者：
Yan-Fei Jiang;S. Tremaine
中科院分区：
文献类型：
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作者：
Yan-Fei Jiang;S. Tremaine
我们研究了太阳附近的宽双星在引力摄动作用下的轨道演化。我们包括银河系潮汐场的影响，并继续跟踪恒星后，他们成为无约束的。对于各种各样的初始半长轴和形成时间，我们发现，数量密度（每单位对数间隔的投影分离的恒星）表现出最小的几倍的雅可比半径r J，等于1.7 pc的太阳质量恒星的二进制。内部的密度峰值是由束缚双星的原始分布引起的，而外部的密度峰值在100-300 pc的距离处，是由以前的束缚双星缓慢地漂移而引起的。外峰在盘星的位置和速度上产生了显着的长程相关性，这在大型天体测量中应该是可以检测到的，如盖亚，可以测量精确的三维距离和速度。
We study the orbital evolution of wide binary stars in the solar neighbourhood due to gravitational perturbations from passing stars. We include the effects of the Galactic tidal field and continue to follow the stars after they become unbound. For a wide variety of initial semimajor axes and formation times, we find that the number density (stars per unit logarithmic interval in projected separation) exhibits a minimum at a few times the Jacobi radius r J , which equals 1.7 pc for a binary of solar-mass stars. The density peak interior to this minimum arises from the primordial distribution of bound binaries, and the exterior density, which peaks at a separation of ∼100-300 pc, arises from formerly bound binaries that are slowly drifting apart. The exterior peak gives rise to a significant long-range correlation in the positions and velocities of disc stars that should be detectable in large astrometric surveys such as Gaia that can measure accurate three-dimensional distances and velocities.