Radiation properties and images of loop quantum Reissner-Nordstr\"om black hole with a thin accretion disk

TL;DR

This paper explores the properties of a loop quantum Reissner-Nordstr"om black hole, analyzing its geodesics, shadow, and accretion disk radiation to understand quantum gravity effects on observable phenomena.

Contribution

It provides a detailed analysis of the black hole's geodesics, shadow, and radiation properties, incorporating quantum gravity effects and observational constraints.

Findings

Quantum parameter $$ increases the ISCO radius.

Black hole shadow size constrains quantum and charge parameters.

Radiation properties differ from classical black holes, influenced by quantum effects.

Abstract

We investigate the characteristics of circular geodesics around loop quantum Reissner-Nordstr\"om black hole (LQRNBH) and the radiation properties and observational appearance of a thin accretion disk around it. By calculating the shadow radius and utilizing observational data from M87* and Sgr A*, we derive constraints on the quantum parameter $\zeta$ and charge parameter $Q$. The timelike circular geodesics around LQRNBH and the influence of the model parameters on the circular motion are also discussed. It is found that contrary to the case of the parameter $Q$, the increase of the quantum parameter $\zeta$ leads to the increase of the radius of the innermost stable circular orbit (ISCO). Then, by considering a thin accretion disk model, various radiation properties of the LQRNBH and the effects of the model parameters on them are studied. Concrete examples are provided for quantitative comparison of the radiation properties between LQRNBH and Schwarzschild black hole. With the ray-tracing method, the isoradial curves, redshift distributions, and the observed radiation fluxes of the direct and secondary images of the LQRNBH with the thin accretion disk for various model parameters and observation angles are numerically calculated and discussed. These results are beneficial for our understanding of the physical consequences of loop quantum gravity effect.