# Multi-level images around Kerr-Newman black holes

@article{Hou2022MultilevelIA, title={Multi-level images around Kerr-Newman black holes}, author={Yehui Hou and P. Liu and Minyong Guo and Haopeng Yan and Bin Chen}, journal={Classical and Quantum Gravity}, year={2022} }

We study the lensing eﬀects of Kerr-Newman (KN) black holes and the multi-level images of luminous sources around the black holes. We obtain the analytic forms of the lens equations in KN spacetime and derive approximately their limiting forms for photon emissions near the bounded photon orbits. After deriving the expressions of three key parameters γ, δ and τ, we investigate the primary, the secondary and the higher-order images of spherical sources and equatorial disk-like sources. In…

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## References

SHOWING 1-10 OF 36 REFERENCES

Lensing by Kerr black holes

- PhysicsPhysical Review D
- 2020

Interpreting horizon-scale observations of astrophysical black holes demands a general understanding of null geodesics in the Kerr spacetime. These may be divided into two classes: "direct" rays that…

Testing gravity with black hole shadow subrings

- PhysicsClassical and Quantum Gravity
- 2022

The black hole shadow, first observed by the Event Horizon Telescope in 2017, is the newest method for studying black holes and understanding gravity. Much work has gone into understanding the shadow…

Distinguishing gravitational and emission physics in black hole imaging: spherical symmetry

- PhysicsMonthly Notices of the Royal Astronomical Society
- 2022

Imaging a supermassive black hole and extracting physical information requires good knowledge of both the gravitational and the astrophysical conditions near the black hole. When the geometrical…

Analytical study of higher-order ring images of the accretion disk around a black hole

- PhysicsPhysical Review D
- 2022

Gennady S. Bisnovatyi-Kogan 3, ∗ and Oleg Yu. Tsupko † Space Research Institute of Russian Academy of Sciences, Profsoyuznaya 84/32, Moscow 117997, Russia National Research Nuclear University MEPhI…

Charged black-bounce spacetimes: Photon rings, shadows and observational appearances

- Physics
- 2021

The photon ring, shadow and observational appearance of the emission originating near a charged black-bounce are investigated. Based on the geodesic analysis, we determine the upper and lower limits…

Observational appearances of a f(R) global monopole black hole illuminated by various accretions

- PhysicsThe European Physical Journal C
- 2021

In this paper, we explore three simple models of accretions on a global monopole black hole in f(R) theory, and numerically study the corresponding observational appearances as seen by an observer…

Black Hole Images as Tests of General Relativity: Effects of Spacetime Geometry

- Physics
- 2021

The image of a supermassive black hole surrounded by an optically-thin, radiatively-inefficient accretion flow, like that observed with the Event Horizon Telescope, is characterized by a bright ring…

Black Hole Images as Tests of General Relativity: Effects of Plasma Physics

- Physics
- 2021

The horizon-scale images of black holes obtained with the Event Horizon Telescope have provided new probes of their metrics and tests of General Relativity. The images are characterized by a bright,…

Separating astrophysics and geometry in black hole images

- PhysicsPhysical Review D
- 2021

The observation of the shadow of the supermassive black hole M87∗ by the Event Horizon Telescope (EHT) is sensitive to the spacetime geometry near the circular photon orbit and beyond, and it thus…

Photon rings of spherically symmetric black holes and robust tests of non-Kerr metrics

- PhysicsPhysical Review D
- 2021

Under very general assumptions on the accretion flow geometry, images of a black hole illuminated by electromagnetic radiation display a sequence of photon rings (demagnified and rotated copies of…