Observing axions through photon ring dimming of black holes
Observing axions through photon ring dimming of black holes
复制标题
DOI：
10.1103/physrevd.107.123505
复制
发表时间：
2022-12
影响因子：
5
通讯作者：
Kimihiro Nomura;Kaishu Saito;J. Soda
中科院分区：
文献类型：
--
作者：
Kimihiro Nomura;Kaishu Saito;J. Soda
众所周知，黑洞附近存在磁场，由于强大的引力，光子可以绕过黑洞。利用这些事实，我们可以探测假想的赝标量粒子，即所谓的轴子。事实上，光子在磁场中传播时可以转化为轴子。这些光子转换成轴子导致黑洞阴影周围的光子环变暗。我们表明，光子环调光可以有效地发生超大质量黑洞。值得注意的是，光子环的最大变暗率是25%。在M87* 的情况下，如果角分辨率达到10 ^{-5}角秒，则在X射线和γ射线波段将观察到10%的调光。调光的频带和幅度取决于轴子-光子耦合和轴子质量。因此，光子环的畸变光谱为探测轴子提供了一种新的工具。
It is known that magnetic fields exist near black holes and photons can go around black holes due to strong gravity. Utilizing these facts, we can probe hypothetical pseudoscalar particles, so-called axions. In fact, photons can be converted into axions when they propagate in a magnetic field. The conversion of such photons into axions leads to a dimming of the photon ring around the black hole shadow. We show that photon ring dimming can occur efficiently for supermassive black holes. Remarkably, it turns out that the maximal dimming rate of the photon ring is 25%. In the case of M87*, the dimming of 10% will be observed in the X-ray and gamma-ray bands if the angular resolution of $10^{-5}$ arcsec is achieved. The frequency band and the magnitude of the dimming depend on the axion-photon coupling and axion mass. Hence, the distorted spectrum of the photon ring provides a novel tool for detecting axions.