论文标题
在带有多个光子球的黑洞中出现一个插入星星
Appearance of an Infalling Star in Black Holes with Multiple Photon Spheres
论文作者
论文摘要
光子球在黑洞附近的发光物体的成像中起关键作用。在本文中，我们检查了一颗恒星自由落在毛茸茸的黑洞中的观察性外观，该恒星可以在事件范围之外拥有一个或两个光子球。当存在一个单个光子球体时，通过远处观察者测量的总亮度会随着时间的时间呈指数下降。由于在不同时间绕着光子球周围绕的光子的连续到达，因此特定的观察者会看到一系列的光闪光随着强度降低，具有相似的频率含量。尽管在具有两个光子球的情况下，光子暂时被困在光子球之间会导致总亮度的峰值，后来又有缓慢的指数衰减。另外，这些光子导致特定观察者看到的另外一系列光闪光。
Photon spheres play a pivotal role in the imaging of luminous objects near black holes. In this paper, we examine observational appearances of a star freely falling in hairy black holes, which can possess one or two photon spheres outside the event horizon. When there exists a single photon sphere, the total luminosity measured by distant observers decreases exponentially with time at late times. Due to successive arrivals of photons orbiting around the photon sphere different times, a specific observer would see a series of light flashes with decreasing intensity, which share a similar frequency content. Whereas in the case with two photon spheres, photons temporarily trapped between the photon spheres can cause a peak of the total luminosity, which is followed by a slow exponential decay, at late times. In addition, these photons lead to one more series of light flashes seen by the specific observer.
