标题： 相对论效应在环联星盘演化中的作用：打破椭圆黑洞双星系统周围的极性对齐 显示英文标题

标题： Relativistic Effects on Circumbinary Disk Evolution: Breaking the Polar Alignment around Eccentric Black Hole Binary Systems

摘要： 我们研究广义相对论（GR）对所有尺度上双星周围环双星盘的演化和对齐的影响。 我们将双星的相对论近日点进动引入到流体动力学代码{\sc phantom}中。 我们发现，GR 的影响可以抑制环双星盘的稳定极轴对齐，这取决于相对论双星近日点进动的时间尺度与盘的节点进动时间尺度的比较。 研究环双星盘演化时通常忽略 GR 的影响，这对于低质量或远距离分离的双星系统是一个合理的简化。 在这种情况下，只要盘的初始错位足够大，就会发生极轴对齐。 然而，具有非常短的相对论进动时间尺度的系统无法极轴对齐，而是趋向于共面对齐。 在时间尺度相近的中间区域，结果取决于盘的特性。 在波动盘区域（其中盘的粘滞参数小于纵横比，$\alpha<H/r$），极轴对齐更有可能发生，因为盘在径向上有良好的沟通。 在粘滞盘区域，盘的断裂更可能发生。 多个环可能会相互破坏性地作用，导致盘寿命较短，并使盘趋向于共面对齐。 在主序星或恒星级黑洞双星周围，极轴对齐可能在远离双星的地方被抑制，但一般来说，盘的内部部分可以对齐到极轴。 对于靠近双星分离的超大质量黑洞周围的盘，极轴对齐可能完全被抑制。 显示英文摘要

摘要： We study the effects of general relativity (GR) on the evolution and alignment of circumbinary disks around binaries on all scales. We implement relativistic apsidal precession of the binary into the hydrodynamics code {\sc phantom}. We find that the effects of GR can suppress the stable polar alignment of a circumbinary disk, depending on how the relativistic binary apsidal precession timescale compares to the disk nodal precession timescale. Studies of circumbinary disk evolution typically ignore the effects of GR which is an appropriate simplification for low mass or widely separated binary systems. In this case, polar alignment occurs providing that the disks initial misalignment is sufficiently large. However, systems with a very short relativistic precession timescale cannot polar align and instead move toward coplanar alignment. In the intermediate regime where the timescales are similar, the outcome depends upon the properties of the disk. Polar alignment is more likely in the wavelike disk regime (where the disk viscosity parameter is less than the aspect ratio, $\alpha<H/r$) since the disk is in good radial communication. In the viscous disk regime disk breaking is more likely. Multiple rings can destructively interact with one another resulting in short disk lifetimes, and the disk moving towards coplanar alignment. Around main-sequence star or stellar mass black hole binaries, polar alignment may be suppressed far from the binary but in general the inner parts of the disk can align to polar. Polar alignment may be completely suppressed for disks around supermassive black holes for close binary separations.