论文标题
旋转黑洞遇到的重力波捕获
Gravitational Wave Capture in Spinning Black Hole Encounters
论文作者
论文摘要
最初未结合的两个黑洞的轨道可以通过在恒星簇中的紧密相遇中发射引力波来转化为绑定的轨道，这被称为重力波（GW）捕获。在数值相对论的背景下研究了黑洞对GW捕获的自旋影响。当黑洞具有与牛顿后近似值所预期的相等质量时，相遇期间的辐射能量取决于有效自旋。当两个黑洞的旋转在飞行遭遇的情况下，都会与轨道角动量进行抗结，这会产生最强的发射。但是在直接合并的情况下，情况恰恰相反：最强的发射来自带对齐的旋转到轨道角动量的黑色孔。 GW之间直接合并捕获的部分与$ v^{4/7} $成比例增加，假设遭遇中的折缘距离均匀分布，其中$ v $是群集的速度分散，这意味着GW捕获量的直接合并$ v = 150 $ km s $ km s $ s $ s $ s $ s $^^ - ^$^ - 1^ - 1^$^^^^$^^$^ - { -
The orbits of two black holes which are initially unbound can be transformed into bound orbits by emitting gravitational waves during close encounters in a star cluster, which is called a gravitational wave (GW) capture. The effects of spin of black holes on GW capture are investigated in the context of numerical relativity. The radiated energy during the encounter is dependent on the effective spin when the black holes have the equal masses as expected from post-Newtonian approximation. The strongest emission is produced when the spins of both black holes are anti-aligned to the orbital angular momentum in the case of fly-by encounters. But the opposite is true in the case of direct merging: the strongest emission comes from the black holes with aligned spins to the orbital angular momentum. The fraction of direct merging among the GW captures increases in proportional to $v^{4/7}$ assuming the uniform distribution of pericenter distances in the encounters, where $v$ is the velocity dispersion of cluster, which means about 5 % of GW capture leads to the direct merging for star clusters with $v=150$ km s$^{-1}$.
