Shadow of Kerr black hole surrounded by a cloud of strings in Rastall gravity and constraints from M87*

Abstract

Motivated by the first image of a black hole captured by the Event Horizon Telescope (EHT), there has been a surge of research using observations of black hole shadows to test theories of gravity. In this paper, we carry out a study related to the shadow of Kerr black holes surrounded by a cloud of strings in Rastall gravity, which deviates from the Kerr black hole due to the presence of the string parameter $a_0$ and the parameter $\beta$. The horizons, ergospheres, and photon region of the black hole are shown. Moreover, we explore the shadow and observations of the black hole, which are closely linked to the parameters $a_0$ and $\beta$. By treating \text{M87*} as a Kerr black hole surrounded by a cloud of strings under Rastall gravity, we constrain the black hole parameters using the EHT observations. For a given $\beta$, the circularity deviation of the black hole obeys $\Delta C\lesssim 0.1$ in all regions. The angular diameter ${\theta }_d=42\pm 3\mu as$ provides the upper bound of parameters $a$ and $a_0$ for fixed $\beta$. The shadow axis ratio satisfies the observation data of EHT ($1<D_x\lesssim 4/3$) in the whole space for a given $\beta$. These results are consistent with the public information from EHT. In other words, candidates for real astrophysical black holes can be Kerr black holes surrounded by a cloud of strings in Rastall gravity.

27 pages, 14 figures

References in corpus (37)

• First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole
• First M87 Event Horizon Telescope Results. VI. The Shadow and Mass of the Central Black Hole
• First M87 Event Horizon Telescope Results. IV. Imaging the Central Supermassive Black Hole
• First M87 Event Horizon Telescope Results. V. Physical Origin of the Asymmetric Ring
• First M87 Event Horizon Telescope Results. II. Array and Instrumentation
• First M87 Event Horizon Telescope Results. III. Data Processing and Calibration
• Horizon-scale tests of gravity theories and fundamental physics from the Event Horizon Telescope image of Sagittarius A${}^{\ast }$
• Magnetically charged black holes from non-linear electrodynamics and the Event Horizon Telescope
• Null geodesics and shadow of a rotating black hole in extended Chern-Simons modified gravity
• Black holes with scalar hair in light of the Event Horizon Telescope
• Einstein and Rastall Theories of Gravitation in Comparison
• Parameter estimation of hairy Kerr black holes from its shadow and constraints from M87*
• Tests of Loop Quantum Gravity from the Event Horizon Telescope Results of Sgr A${}^{\ast }$
• Shadow analysis for rotating black holes in the presence of plasma for an expanding universe
• Shadow and weak deflection angle of extended uncertainty principle black hole surrounded with dark matter
• Constraining alternatives to the Kerr black hole
• Shadows of parametrized axially symmetric black holes allowing for separation of variables
• Cosmological constant corrections to the photon sphere and black hole shadow radii
• Shadows and lensing of black holes immersed in strong magnetic fields
• Revisiting the shadow of braneworld black holes
• Thermodynamics and Shadows of GUP-corrected Black Holes with Topological Defects in Bumblebee Gravity
• Weak gravitational lensing and shadow of a GUP-modified Schwarzschild black hole in the presence of plasma
• Kerr black holes with synchronised Proca hair: lensing, shadows and EHT constraints
• Constraints on charged Symmergent black hole from shadow and lensing
• Thin-shell wormholes in Rastall gravity
• Images from disk and spherical accretions of hairy Schwarzschild black holes
• Shadow revisiting and weak gravitational lensing with Chern-Simons modification
• Weak deflection angle by Casimir wormhole using Gauss-bonnet theorem and its shadow
• Tunneling Analysis of Kerr-Newman Black Hole-Like Solution in Rastall Theory
• Polarimetric signatures of the photon ring of a black hole that is pierced by a cosmic axion string
• Rotating black hole mimicker surrounded by the string cloud
• Shadow, absorption and Hawking radiation of a Schwarzschild black hole surrounded by a cloud of strings in Rastall gravity
• Rotating Black Hole in Kalb-Ramond Gravity: Constraining Parameters by Comparison with EHT Observations of Sgr A* and M87*
• Modeling the black holes surrounded by a dark matter halo in the galactic center of M87
• Dirac quasinormal modes of power-Maxwell charged black holes in Rastall gravity
• Source of black bounces in Rastall gravity
• Qusinormal oscillations and late-time tail of massless scalar perturbations of a magnetized black hole in Rastall gravity

Cited by in corpus (3)

• Thermodynamics and Joule-Thomson Expansion for Schwarzschild-AdS Black Holes with Cloud of Strings and Quintessential-like Fluid
• Optical images of the Kerr-Sen black hole and thin accretion disk
• Gravitational Collapse of an Inhomogeneous Fluid in Rastall Theory