Algorithms and radiation dynamics for the vicinity of black holes. II. Results

TL;DR

This paper investigates the physics of accretion disks near black holes, analyzing photon trajectories, radiation forces, imaging outcomes, and disk stability, with implications for understanding black hole spin and accretion dynamics.

Contribution

It provides new insights into radiation effects and imaging of accretion disks around Schwarzschild and Kerr black holes, including effects of spacetime rotation and thermal radiation.

Findings

Radiation forces significantly influence disk dynamics.

Imaging plots can estimate black hole spin.

Thermal radiation causes orbit degradation.

Abstract

We present the results of our studies on accretion disks in the proximity of astrophysical black holes. These disks can be of varying degrees of opacity, geometrical shapes, sizes, and volumes. The central compact object is a Schwarzschild or a Kerr black hole of various spin parameters. We describe the environment and the physics of the systems under examination and the disk models considered. We first investigate the effects of the {spacetime} rotation on photon trajectories. We then examine the radiation forces recorded at various points of the arrangement inside and outside the disk material, and in the inner, outer, and off-equatorial material orbits. We document and explore the radiation effects, which are revealed to be significant and {positively} consequential. Afterward, we inspect the possible imaging outcome of various types of black hole and accretion disk configurations, and we show our results for plots that could be used to estimate the central black hole spin in a system. Finally, we show results regarding the disk material orbit degradation due to its thermal radiation.