Image of Bonnor black dihole with a thin accretion disk and its polarization information

TL;DR

This study models the images and polarization of a Bonnor black dihole with a thin accretion disk, revealing how magnetic parameters and inclination angles influence brightness and polarization patterns, and compares these with M87* images.

Contribution

It provides the first detailed analysis of polarization patterns and brightness variations of Bonnor black diholes considering different radiation models and compares them with real black hole images.

Findings

Image brightness increases with magnetic parameter and inclination angle.

Synchrotron radiation produces brighter images than black body radiation.

Polarization patterns depend sharply on magnetic parameter and inclination angle.

Abstract

We have studied the image of Bonnor black dihole surrounded by a thin accretion disk where the electromagnetic emission is assumed to be dominated respectively by black body radiation and synchrotron radiation. Our results show that the intensity of Bonnor black dihole image increases with the magnetic parameter and the inclination angle in both radiation models. The image of Bonnor black dihole in the synchrotron radiation model is one order of magnitude brighter than that in the black body radiation model, but its intensity in the former decreases more rapidly with the radial coordinate. Especially, for the synchrotron radiation model, the intensity of the secondary image is stronger than that of the direct image at certain an inclination angle. We also present the polarization patterns for the images of Bonnor black dihole arising from the synchrotron radiation, which depend sharply on the magnetic parameter and inclination angle. Finally, we make a comparison between the polarimetric images of Bonnor black dihole and M87*. Our result further confirms that the image of black hole depends on the black hole's properties itself, the matter around black hole and the corresponding radiation occurred in the accretion disk.