论文标题
光子区域，阴影可观察到来自电荷旋转黑洞的M87*的约束
Photon regions, shadow observables and constraints from M87* of a charged rotating black hole
论文作者
论文摘要
受到\ emph {事件范围望远镜}（EHT）实验的超级质量黑洞M87*的观察的启发，黑洞物理学的显着涌现是使用黑洞的观察力来区分一般相对论（GR）的一般相对论（GR），并可以改进的重力理论（MOG），也可以帮助披露天文学洞中的黑洞。在本文中，我们将广泛地研究一个带电的旋转黑洞中的共形黑洞，其中与电荷相关的术语与通常的Kerr-Newman（KN）黑洞的差异不同。我们研究了时空特性，包括地平线，巨石和光子区域。之后，我们显示了黑洞阴影的边界，并研究了其特征性可观察物。这些特征密切取决于自旋和电荷参数，这些特征与Kerr和Kn黑洞中的旋转参数相比。然后以保形重力为M87*一个带电的旋转黑洞，我们还通过EHT实验的观察约束来限制黑洞参数。我们发现，对M87* Black Hole满足了$ΔC\ Lessim 0.1 $的约束，$ΔC\ Lessim 0.1 $，在阴影轴向比率上，$ 1 <d_x \ Lessim 4/3 $，对于M87* Black Hole，对于共同型中带电的旋转黑洞的整个参数旋转的参数空间满足。但是，阴影角直径$θ_d= 42 \ pm3μas$将在参数空间上给出上限。我们的发现表明，当前在共形重力中带有充电的旋转黑洞可能是天体物理黑洞的候选者。此外，对轴向比率的EHT观察$ d_x $可能会帮助我们区分Kerr黑洞和在某些参数空间中的共形性重力中的电流带电的旋转黑洞。
Inspired by the observations of supermassive black hole M87* in \emph{Event Horizon Telescope }(EHT) experiment, a remarkable surge in black hole physics is to use the black hole shadow's observables to distinguish general relativity (GR) and modified theories of gravity (MoG), which could also help to disclose the astrophysical nature of the center black hole in EHT observation. In this paper, we shall extensively carry out the study of a charged rotating black hole in conformal gravity, in which the term related with the charge has different falloffs from the usual Kerr-Newman (KN) black hole. We investigate the spacetime properties including the horizons, ergospheres and the photon regions; afterward, we show the boundary of black hole shadow and investigate its characterized observables. The features closely depend on the spin and charge parameters, which are compared with those in Kerr and KN black holes. Then presupposing the M87* a charged rotating black hole in conformal gravity, we also constrain the black hole parameters via the observation constraints from EHT experiment. We find that the constraints on the inferred circularity deviation, $ΔC \lesssim 0.1$, and on the shadow axial ratio, $1< D_x \lesssim 4/3$, for the M87* black hole are satisfied for the entire parameter space of the charged rotating black hole in conformal gravity. However, the shadow angular diameter $θ_d = 42 \pm 3 μas$ will give upper bound on the parameter space. Our findings indicate that the current charged rotating black hole in conformal gravity could be a candidate for astrophysical black holes. Moreover, the EHT observation on the axial ratio $D_x$ may help us to distinguish Kerr black hole and the current charged rotating black hole in conformal gravity in some parameter space.
