论文标题
圆形赤道KERR轨道器发射的光子发射
Photon Emission from Circular Equatorial Kerr Orbiters
论文作者
论文摘要
我们认为圆形赤道KERR轨道器产生的单色和各向同性光子发射。我们得出了光子逃逸概率的分析表达式，以及在天体球上收集的红移依赖性总通量作为发射半径和黑洞参数的函数。这些计算至关重要的是，临界曲线描绘了光子从每个发射极天空中光子捕获的区域逃脱的区域。该曲线概括为有限的轨道半径通常的Kerr临界曲线，并在高旋转极限中显示有趣的特征，我们通过开发有关极端性的扰动扩张来研究。尽管最内向的稳定圆形轨道似乎可以接近事件范围的黑洞，但在这种制度中，我们发现光子逃逸概率倾向于$ 5/12+1/（\ sqrt {5}π}π）\ Arctan \ Arctan \ sqrt \ sqrt {5/3} {5/3} \ actib actib of54.65 \ liold54.65 \％$ $ $。我们还获得了一个简单的公式，用于在天体球体上接收到的通量分布，该公式为非零。这证实了一个高旋转黑洞的近水压几何形状原则上可观察到。这些结果要求我们引入一种新型类型的近水压双尺度极限。我们将在无穷大的总通量中观察到的浸入是黑洞的烙印：黑洞“咬”。
We consider monochromatic and isotropic photon emission from circular equatorial Kerr orbiters. We derive analytic expressions for the photon escape probability and the redshift-dependent total flux collected on the celestial sphere as a function of emission radius and black hole parameters. These calculations crucially involve the critical curve delineating the region of photon escape from that of photon capture in each emitter's sky. This curve generalizes to finite orbital radius the usual Kerr critical curve and displays interesting features in the limit of high spin, which we investigate by developing a perturbative expansion about extremality. Although the innermost stable circular orbit appears to approach the event horizon for very rapidly spinning black holes, we find in this regime that the photon escape probability tends to $5/12+1/(\sqrt{5}π)\arctan\sqrt{5/3}\approx54.65\%$. We also obtain a simple formula for the flux distribution received on the celestial sphere, which is nonzero. This confirms that the near-horizon geometry of a high-spin black hole is in principle observable. These results require us to introduce a novel type of near-horizon double-scaling limit. We explain the dip observed in the total flux at infinity as an imprint of the black hole: the black hole "bite".
