Minidisk Dynamics in Accreting, Spinning Black Hole Binaries: Simulations in Full General Relativity
Minidisk Dynamics in Accreting, Spinning Black Hole Binaries: Simulations in Full General Relativity
复制标题
DOI：
10.3847/2041-8213/abee21
复制
发表时间：
2021-02
期刊：
影响因子：
--
通讯作者：
V. Paschalidis;J. Bright;M. Ruiz;R. Gold
中科院分区：
文献类型：
--
作者：
V. Paschalidis;J. Bright;M. Ruiz;R. Gold
我们在完全广义相对论中对吸积的等质量二元黑洞进行了磁流体力学模拟，重点研究了黑洞自转对小圆盘动力学形成和演化的影响。我们发现，在激发末期，小圆盘的大小主要由潮汐和每个黑洞的有效最内稳定轨道之间的相互作用决定。我们的计算支持，当每个黑洞周围的Hill球体明显大于黑洞有效的最内稳定轨道时，就形成了一个小圆盘。随着双星的激发，Hill球体的半径减小，小圆盘的大小也随之缩小。因此，当Hill球体内没有更多的稳定轨道时，与迷你圆盘相关的电磁特征可能会在合并之前逐渐消失。特别是，硬电磁成分在这类系统的光谱中逐渐消失，可能提供合并黑洞双星的特征特征。因此，对于给定总质量的双星，时间尺度到小圆盘的“蒸发”应该取决于黑洞的自转和质量比。我们还证明了具有自旋的吸积双黑洞在将吸积能量转化为喷流光度方面具有更高的效率。这些结果可能为未来估计黑洞自转提供新的方法。
We perform magnetohydrodynamic simulations of accreting, equal-mass binary black holes in full general relativity focusing on the impact of black hole spin on the dynamical formation and evolution of minidisks. We find that during the late inspiral the sizes of minidisks are primarily determined by the interplay between the tidal field and the effective innermost stable orbit around each black hole. Our calculations support that a minidisk forms when the Hill sphere around each black hole is significantly larger than the black hole’s effective innermost stable orbit. As the binary inspirals, the radius of the Hill sphere decreases, and minidisks consequently shrink in size. As a result, electromagnetic signatures associated with minidisks may be expected to gradually disappear prior to merger when there are no more stable orbits within the Hill sphere. In particular, a gradual disappearance of a hard electromagnetic component in the spectrum of such systems could provide a characteristic signature of merging black hole binaries. For a binary of given total mass, the timescale to minidisk “evaporation” should therefore depend on the black hole spins and the mass ratio. We also demonstrate that accreting binary black holes with spin have a higher efficiency for converting accretion power to jet luminosity. These results could provide new ways to estimate black hole spins in the future.