Kerr Black hole shadows in Melvin magnetic field with stable photon orbits

Abstract

We have studied the shadows of black hole immersed in Melvin magnetic field. Due to the existence of Melvin magnetic field, the shadow of Melvin-Schwarzschild black hole becomes more elongated in the horizontal direction so that the black silhouette changes from a perfect circle to an ellipse.We also present the change of the eccentricity for the ellipse-shaped shadow with the magnetic field parameter. For a rotating black hole, with the increasing of the rotation parameter, the ellipse-shaped shadow becomes gradually a D-shaped silhouette elongated in the horizontal direction.Moreover, the right part of the D-shaped and elongated shadow boundary can be matched very well by a part of an ellipse, and the corresponding eccentricity decreases with the rotation parameter and increases with the magnetic field parameter. In addition, there also exist some self-similar fractal structures in the shadow of Melvin-Kerr black hole arising from the chaotic motion of photon. These behavior of shadow of Melvin-Kerr black hole can help us to understand the black hole shadow and the magnetic field around black hole.

QED Effects on Kerr Black Hole Shadows immersed in uniform magnetic fields

“…Moreover, we found that when the spin a goes to extremality, the hair structure would be very evident. A similar hair structure was also found in [42], where the Kerr Black hole shadows in Melvin magnetic field had been studied. It seems to us that the appearance of the "hair" structure in the shadow could be a common feature for the black hole in a magnetic field.…”

“…5, we can clearly see that the photon hairs become very obvious at a = 0.999 and, in addition to that, the shape of the shadow curve becomes more flattened as the parameter |Λ| gets bigger. As shown in [8,11,12,41,42,46], for non-integrable geodesic equations, the photons may travel in chaotic motions. In particular, in [41,42], the authors investigated the shadows of the black hole immersed in the Melvin magnetic field, and observed the chaotic motions of the photons.…”

“…As shown in [8,11,12,41,42,46], for non-integrable geodesic equations, the photons may travel in chaotic motions. In particular, in [41,42], the authors investigated the shadows of the black hole immersed in the Melvin magnetic field, and observed the chaotic motions of the photons. Furthermore, in [42], the authors found the photon hair appearing at the left of the shadow curve as well, which is very similar to our findings.…”

“…In particular, in [41,42], the authors investigated the shadows of the black hole immersed in the Melvin magnetic field, and observed the chaotic motions of the photons. Furthermore, in [42], the authors found the photon hair appearing at the left of the shadow curve as well, which is very similar to our findings. However the photon hairs found in our work have a bit more complicated structure: they extend two small "hairs" like a claw into the shadow region in a strange way, around the positions where the shadow curve is discontinuous.…”

“…Consequently the motions of the photons get modified as well. Along this line, in [41] and [42], the authors have investigated the Schwarzschild and the Kerr black hole shadows in the Melvin magnetic field. The advantage of this analysis is that the influence of the magnetic field on the black hole shadows can be easily studied.…”