Thin Accretion Disk Around Rotating Hairy Black Hole: Radiative Property and Optical Appearance

TL;DR

This paper investigates how the presence of hairy modifications in rotating black holes affects the observable properties of accretion disks, providing potential tests for alternative gravity theories with upcoming astronomical data.

Contribution

It introduces a method to analyze the radiative and optical properties of accretion disks around rotating hairy black holes derived via gravitational decoupling.

Findings

Deviations from Kerr become significant in rapid rotation cases.

Inner disk regions show notable differences from Kerr predictions.

Results aid in observationally testing hairy black hole models.

Abstract

The gravitational decoupling method systematically generates hairy modifications to the solutions in general relativity due to new gravitational sources. In view of the recent advances in astronomical observations, these hairy solutions are expected to be testable in the near-term observations. In this paper, we study the radiative property and optical appearance of the thin accretion disk around the rotating hairy black holes obtained by gravitational decoupling. We numerically compute the radiative flux, temperature, and differential luminosity of the thin accretion disk, and we also show its bolometric image by the ray-tracing method. By comparing with the results for the Kerr metric, we found that the deviations of the observational properties of the thin accretion disk from those of Kerr metric becomes significant in the rapid rotating case, or in the inner region of the disk. These results guide the observational investigations on the rotating hairy black hole.