Polarized image of a Schwarzschild black hole with a thin accretion disk as photon couples to Weyl tensor

Zelin Zhang,Xin Qin,Songbai Chen,Jiliang Jing

doi:10.1140/epjc/s10052-021-09786-2

Zelin Zhang, Xin Qin + Show 2 more

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https://doi.org/10.1140/epjc/s10052-021-09786-2

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Abstract

We have studied polarized image of a Schwarzschild black hole with an equatorial thin accretion disk as photon couples to Weyl tensor. The birefringence of photon originating from the coupling affect the black hole shadow, the thin disk pattern and its luminosity distribution. We also analyze the observed polarized intensity in the sky plane. The observed polarized intensity in the bright region is stronger than that in the darker region. The stronger effect of the coupling on the observed polarized vector appears only in the bright region close to black hole. These features in the polarized image could help us to understand black hole shadow, the thin accretion disk and the coupling between photon and Weyl tensor.

Highlights

The distribution of polarized intensity and polarized direction in the black hole’s image depend on the propagation of polarized light in the spacetime, which is determined by the parameters of background black hole, the dynamical properties of photon itself and the interactions between photon and other fields
For the direct image caused by the photon with the polarization along lμ (PPL), we find that the intensity in the region near the black hole decreases with α, but in the far region it increases
We have studied polarized image of a Schwarzschild black hole with a thin accretion disk produced by photon coupled to Weyl tensor

Summary

Introduction

The distribution of polarized intensity and polarized direction in the black hole’s image depend on the propagation of polarized light in the spacetime, which is determined by the parameters of background black hole, the dynamical properties of photon itself and the interactions between photon and other fields. The double shadow of a regular phantom black hole has been studied due to birefringence originating from the coupling between Maxwell field and Weyl tensor [38] It is still unclear what effects of the coupling between photon and Weyl tensor on the polarized image of a black hole with a thin accretion disk. The motivation in this paper is to study the image of a thin accretion disk around a black hole under the interaction between Maxwell field and Weyl tensor, and probe the effect of the coupling on the corresponding polarized patterns.

Equation of motion for the photons coupled to Weyl tensor

Summary