Shadow geometry of Kerr MOG naked singularity and analysis of accretion disk luminosity

Abstract

Naked singularities are hypothetical astrophysical entities featuring gravitational singularities without event horizons. In this study, we analyze the shadow properties of Kerr Modified Gravity (Kerr MOG) naked singularities (KMNSs). We show that the KMNS shadow can appear closed, open, or even vanish, depending on the dimensionless spin parameter a, the modified gravity parameter alpha, and the observer's inclination angle. We identify the critical conditions under which the KMNS shadow develops a gap, a unique feature not present in BH shadows. We analyze the properties of a thin accretion disk surrounding a KMNS, within the framework of MOG characterized by the parameter alpha. The study includes a detailed examination of the spacetime geometry and the equations of motion for test particles. In addition, we adopt a simplified model for the disk's radiative flux, temperature distribution, and spectral luminosity. Our analysis primarily focuses on the flux distribution of the accretion disk around KMNS with identical mass but varying spin and MOG deformation parameters. This allows us to explore how modifications in rotation and the MOG parameter alpha influence the radiative properties of the disk. Further, these observational signatures may serve as effective tools for clearly distinguishing KMNS from standard Kerr naked singularities (KNSs), where the MOG parameter alpha = 0

arXiv comment25 pages, 13 captioned figures, Accepted for publication in European Physical Journal C

References in corpus (38)

• First Sagittarius A* Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole in the Center of the Milky Way
• First M87 Event Horizon Telescope Results. VI. The Shadow and Mass of the Central Black Hole
• Calculating black hole shadows: Review of analytical studies
• Scalar-Tensor-Vector Gravity Theory
• Generating rotating regular black hole solutions without complexification
• Black Holes in Modified Gravity (MOG)
• Shadows and deflection angle of charged and slowly rotating black holes in Einstein-Æther theory
• The Bullet Cluster 1E0657-558 evidence shows Modified Gravity in the absence of Dark Matter
• Equilibrium configurations from gravitational collapse
• A model for non-singular black hole collapse and evaporation
• Astrophysical Violations of the Kerr Bound as a Possible Signature of String Theory
• Image of the Janis-Newman-Winicour naked singularity with a thin accretion disk
• Shadow of a Naked Singularity without Photon Sphere
• Timelike geodesics of a modified gravity black hole immersed in an axially symmetric magnetic field
• Rotating regular black holes in conformal massive gravity
• Shadows of Kerr-like black holes in a modified gravity theory
• Accretion disk luminosity for black holes surrounded by dark matter
• Black-hole microstate spectroscopy: ringdown, quasinormal modes, and echoes
• Thin accretion disk signatures of slowly rotating black holes in Hořava gravity
• Accretion disks around black holes in Scalar-Tensor-Vector Gravity
• Constraints on Barrow entropy from M87* and S2 star observations
• Dynamics of a charged particle around a weakly magnetized naked singularity
• Inner-most stable circular orbit in Kerr-MOG black hole
• Analysis of accretion disk around a black hole in dRGT massive gravity
• Periodic orbits and their gravitational wave radiations around the Schwarzschild-MOG black hole
• Light trajectory and shadow shape in the rotating naked singularity
• Closed Timelike Curves, Singularities and Causality: A Survey from Gödel to Chronological Protection
• Reversible dynamics with closed time-like curves and freedom of choice
• Shadow Geometry of Kerr Naked Singularities
• Shadows and accretion disk images of charged rotating black hole in modified gravity theory
• A Study of Black Holes in $F(R)-$ModMax Gravity: Gravitational Lensing and Constraints from EHT Observations
• The ring-shaped shadow of rotating naked singularity with a complete photon sphere
• Causality Aspects of Modified Kerr-Newman spacetimes
• Shadows and Optical Appearances of Black Holes in $R^2$ Gravity
• Shadow Cast by the Kerr MOG Black Hole under the Influence of Plasma and Constraints from EHT Observations
• Gravitational Lensing by a Dark Compact Object in Modified Gravity and Observational Constraints from Einstein Rings
• Shadow of F(R)-EH Black Hole and Constraints from EHT Observations
• On the role of closed timelike curves and confinement structure around Kerr-Newman singularity

Cited by in corpus (1)

• Light propagation and quasinormal modes of a topologically charged Schwarzschild-Klinkhamer wormhole