Shadows of rotating Hayward-de Sitter black holes with astrometric observables

TL;DR

This paper analyzes the shadows of rotating Hayward-de Sitter black holes, focusing on how spin, magnetic charge, and cosmological constant affect their shape and size using astronomical observables.

Contribution

It introduces a quantitative analysis of black hole shadow distortions considering multiple parameters, extending previous work to include the effects of a cosmological constant.

Findings

Spin distorts black hole shadows.

Magnetic monopole charge increases deformation.

Cosmological constant influences shadow size and shape.

Abstract

Motivated by recent work on rotating black hole shadow [Phys. Rev. D101, 084029 (2020)], we investigate the shadow behaviors of rotating Hayward-de Sitter black hole for static observers at a finite distance in terms of astronomical observables. This paper uses the newly introduced distortion parameter in [arXiv:2006.00685] to describe the shadow's shape quantitatively. We show that the spin parameter would distort shadows and the magnetic monopole charge would increase the degree of deformation. At the same time, the distortion could be relieved because of the cosmological constant and the distortion would increase with the distance from the black hole. Besides, the spin parameter, magnetic monopole charge and cosmological constant increase will cause the shadow to shrink.