论文标题
低旋转100 msun黑洞的形成
Formation of low-spinning 100 Msun black holes
论文作者
论文摘要
据推测，在密集的恒星环境中合并了两个巨大的恒星 - 原素BHS，可能导致在配对稳定的质量间隙（50-135 MSUN）中形成巨大的BH。这种合并形成的BH通常通常具有高自旋（a = 0.7）。如果这样的大规模BH获得了另一个BH，则可能导致Ligo/Wirgo在重力波中检测到另一次合并。收购同伴可能会受到重力波/后坐力的阻碍，这是第一次合并伴随的，并且可能会迅速从其母体球状或核簇中取出巨大的BH。我们测试是否有可能将大规模合并的BH保留在其父群中，并且自旋较低。这样的BH与原始BH无法区分。我们采用了黑洞合并的数值相对性计算的结果来探索用于合并BH质量和旋转的各种组合的重力波后方速度的范围。我们将合并形成的大规模BH速度与球状和核簇的典型逃逸速度进行了比较。我们表明，如果BH的旋转较低（a <0.3），则极不可能形成并保留100 mSUN BH，因为此类BHS获得高后坐力速度（> 200 km/s），超过球体簇（50 km/s）的典型逃逸速度。但是，可以形成非常低的旋转（a = 0.1）和大规模（100 msun）BH，并保留在银河核星簇中。即使如此庞大的合并BHS具有如此低旋转的形成过程（400 km/s），它们仍可避免出现高速，因为大规模的核簇具有很高的逃逸速度（300-500 km/s）。因此，将来检测到具有低自旋的配对质量质量间隙中的大量BH将无法证明存在原始BHS，有时声称这些BHS有时具有低自旋和任意高的质量。
It is speculated that a merger of two massive stellar-origin BHs in a dense stellar environment may lead to the formation of a massive BH in the pair-instability mass gap (50-135 Msun). Such a merger-formed BH is expected to typically have a high spin (a=0.7). If such a massive BH acquires another BH it may lead to another merger detectable by LIGO/Virgo in gravitational waves. Acquiring a companion may be hindered by gravitational-wave kick/recoil, which accompanies the first merger and may quickly remove the massive BH from its parent globular or nuclear cluster. We test whether it is possible for a massive merger-formed BH in the pair-instability gap to be retained in its parent cluster and have low spin. Such a BH would be indistinguishable from a primordial BH. We employed results from numerical relativity calculations of black hole mergers to explore the range of gravitational-wave recoil velocities for various combinations of merging BH masses and spins. We compared merger-formed massive BH speeds with typical escape velocities from globular and nuclear clusters. We show that a globular cluster is highly unlikely to form and retain a 100 Msun BH if the spin of the BH is low (a<0.3) as such BHs acquire high recoil speeds (>200 km/s) that exceed typical escape speeds from globular clusters (50 km/s). However, a very low-spinning (a=0.1) and massive (100 Msun) BH could be formed and retained in a galactic nuclear star cluster. Even though such massive merger-formed BHs with such low spins acquire high speeds during formation (400 km/s), they may avoid ejection since massive nuclear clusters have high escape velocities (300-500 km/s). A future detection of a massive BH in the pair-instability mass gap with low spin would therefore not be proof of the existence of primordial BHs, which are sometimes claimed to have low spins and arbitrarily high masses.
