Shadows and accretion disk images of charged rotating black hole in modified gravity theory

He-Bin Zheng; Meng-Qi Wu; Guo-Ping Li; Qing-Quan Jiang

doi:10.1140/epjc/s10052-025-13791-0

2024 Impact factor 4.8

Particles and Fields

Open Access

Eur. Phys. J. C (2025) 85: 46
https://doi.org/10.1140/epjc/s10052-025-13791-0

Regular Article - Theoretical Physics

Shadows and accretion disk images of charged rotating black hole in modified gravity theory

He-Bin Zheng, Meng-Qi Wu, Guo-Ping Li^a and Qing-Quan Jiang

School of Physics and Astronomy, China West Normal University, 637000, Nanchong, China

^a gpliphys@yeah.net

Received: 16 November 2024
Accepted: 1 January 2025
Published online: 21 January 2025

Abstract

In this paper, we study the shadows and images of the accretion disk of Kerr–Newman (KN) black hole (BH) in modified gravity (MOG) theory by using the backward ray-tracing method. And, the influence of spin parameter (a), charge (Q), and MOG parameter ( $α$ $\alpha$ ) on the observed features of BHs are carefully addressed. Interestingly, as $α$ $\alpha$ increases, the flat edge of the BH’s shadow gradually becomes more rounded, the size of shadow enlarges, and the deviation rate ( $δ s$ $\delta s$ ) correspondingly decreases. By tracing the photon around BH, we observe that the trajectory of photon exhibits distortion behavior, i.e., the formation of two “tails” near the Einstein ring, which elongate as a increases. For the accretion disk, it shows that the inner shadow expands with $α$ $\alpha$ , while decreases with Q. The increase of $α$ $\alpha$ exhibits an increasing effect on redshift. At the same parameter level, $α$ $\alpha$ has a more obvious effect on inner shadow and image of BH by comparing with that of Q. Our study implies that both $α$ $\alpha$ and Q have relatively significant effects on the image of the KN-MOG BH with the thin disk accretion, but the influence of $α$ $\alpha$ is much greater. So, this indicates that $α$ $\alpha$ plays a dominant role in this spacetime.

© The Author(s) 2025

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.