Testing Rotating Regular Metrics as Candidates for Astrophysical Black Holes

Abstract

The Event Horizon Telescope, a global submillimeter wavelength very long baseline interferometry array, produced the first image of supermassive black hole M87* showing a ring of diameter ${\theta }_d=42\pm 3\mu$as, inferred a black hole mass of $M=(6.5\pm 0.7)\times 10^9{M}_{\odot }$ and allowed us to investigate the nature of strong-field gravity. The observed image is consistent with the shadow of a Kerr black hole, which according to the Kerr hypothesis describes the background spacetimes of all astrophysical black holes. The hypothesis, a strong-field prediction of general relativity, may be violated in the modified theories of gravity that admit non-Kerr black holes. Here, we use the black hole shadow to investigate the constraints when rotating regular black holes (non-Kerr) can be considered as astrophysical black hole candidates, paying attention to three leading regular black hole models with additional parameters $g$ related to nonlinear electrodynamics charge. Our interesting results based on the systematic bias analysis are that rotating regular black holes shadows may or may not capture Kerr black hole shadows, depending on the values of the parameter $g$. Indeed, the shadows of Bardeen black holes ($g\lesssim 0.26M$), Hayward black holes ($g\lesssim 0.65M$), and non-singular black holes ($g\lesssim 0.25M$) are indistinguishable from Kerr black hole shadows within the current observational uncertainties, and thereby they can be strong viable candidates for the astrophysical black holes. Whereas Bardeen black holes ( $g\le 0.30182M$), Hayward black holes ($g\le 0.73627M$), and non-singular black holes ($g\le 0.30461M$), within the $1\sigma$ region for ${\theta }_d=39\mu$as, are consistent with the observed angular diameter of M87*.

14 pages, 9 figures. Published in ApJ

References in corpus (23)

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• Circular geodesics of Bardeen and Ayon-Beato-Garcia regular black-hole and no-horizon spacetimes
• Understanding photon sphere and black hole shadow in dynamically evolving spacetimes
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• Shadows of CPR black holes and tests of the Kerr metric
• Collision of two general particles around a rotating regular Hayward's black holes
• Comment on "Generic rotating regular black holes in general relativity coupled to non-linear electrodynamics"

Cited by in corpus (26)

• Constraints on black-hole charges with the 2017 EHT observations of M87*
• Black holes with a cosmological constant in bumblebee gravity
• Superradiance evolution of black hole shadows revisited
• No-Hair Theorem in the Wake of Event Horizon Telescope
• Testing Rotating Regular Metrics with EHT Results of Sgr A*
• Parameters estimation and strong gravitational lensing of nonsingular Kerr-Sen black holes
• Testing strong gravitational lensing effects by supermassive compact objects with regular spacetimes
• Investigating effects of dark matter on photon orbits and black hole shadows
• Estimating the cosmological constant from shadows of Kerr--de Sitter black holes
• Quasinormal modes and shadows of a new family of Ayón-Beato-Garc\'ıa black holes
• Testing EGB gravity coupled to bumblebee field and black hole parameter estimation with EHT observations
• Shadow of black hole surrounded by magnetized plasma: Axion-plasmon cloud
• EHT observables as a tool to estimate parameters of supermassive black holes
• Exploring Nonlinear Electrodynamics Theories: Shadows of Regular Black Holes and Horizonless Ultra-Compact Objects
• Signatures of the accelerating black holes with a cosmological constant from the ${\text{Sgr A}}^{\star }$ and ${\text{M87}}^{\star }$ shadow prospects
• Parameter estimation of Kerr-Bertotti-Robinson black holes using their shadows
• Formation of regular black hole from baryonic matter
• Primordial regular black holes as all the dark matter. III. Covariant canonical quantum gravity models
• Black hole in a generalized Chaplygin-Jacobi dark fluid: shadow and light deflection angle
• Is it possible to distinguish between different black hole solutions using the Shapiro time delay?
• A new class of anisotropic rotating fluids and some throat-like sources for Kerr metric as examples
• Physically viable rotating mass solutions surrounding Kerr black hole
• Optical and orbital characterization of spherically symmetric static black holes of self-gravitating new nonlinear electrodynamics model
• Horizon-Brightened Acceleration Radiation and Optical Signatures of Generic Regular Black Holes from Nonlinear Electrodynamics
• Strong field gravitational lensing of particles by a black-bounce-Schwarzschild black hole
• The eye of the storm: A regular Kerr black hole