Photon emission from inside the innermost stable circular orbit
Photon emission from inside the innermost stable circular orbit
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DOI：
10.1103/physrevd.103.104028
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发表时间：
2021-02
影响因子：
5
通讯作者：
Takahisa Igata;K. Kohri;Kota Ogasawara
中科院分区：
文献类型：
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作者：
Takahisa Igata;K. Kohri;Kota Ogasawara
我们考虑这样一种情况，即围绕克尔黑洞最内层稳定圆轨道（ISCO）运行的光源由于无穷小扰动而从边缘稳定轨道轻轻落下。假设光源各向同性地发射光子，我们证明了超过50%的发射光子可以逃逸到无限远的最后半径大约是ISCO半径和事件视界半径之间的一半。为了评估它们，我们从ISCO附近确定发射极轨道，这些轨道对每个黑洞自旋都是唯一指定的，并通过完全指定二维光子碰撞参数空间中的区域来确定光子从克尔时空赤道平面上的任何点逃逸到无限的条件。我们进一步证明了发射体的自行影响光子的逃逸几率，并使发射光子的能量发生蓝移。
We consider a situation where a light source orbiting the innermost stable circular orbit (ISCO) of the Kerr black hole is gently falling from the marginally stable orbit due to an infinitesimal perturbation. Assuming that the light source emits photons isotropically, we show that the last radius at which more than 50% of emitted photons can escape to infinity is approximately halfway between the ISCO radius and the event horizon radius. To evaluate them, we determine emitter orbits from the vicinity of the ISCO, which are uniquely specified for each black hole spin, and identify the conditions for a photon to escape from any point on the equatorial plane of the Kerr spacetime to infinity by specifying regions in the two-dimensional photon impact parameter space completely. We further show that the proper motion of the emitter affects the photon escape probability and blueshifts the energy of emitted photons.