2023/01/03 by Balendra Pratap Singh, Singh, Balendra Pratap · 1 citation
Physics and Astronomy · #Cosmology and Gravitation Theories #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena #General Relativity and Quantum Cosmology (gr-qc) #High Energy Astrophysical Phenomena (astro-ph.HE) #Solar and Space Plasma Dynamics
paper · pdf · doi:10.48550/arxiv.2301.00956
openalex publication_date 2023/01/03 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The rotating black holes in the quintessential dark energy correspond to three horizons: inner, outer, and quintessential horizon. The domain of outer communication is the region between outer and quintessential horizon. Here, in this work we study the photon region and shadows of the quintessential dark energy black holes when the observer stays statically in the domain of outer communication. The quintessential dark energy black holes shadow characterizes by its mass (M), spin parameter (a), quintessential dark energy parameter (ωq), and normalization factor (γ). The dark energy parameter ωq can take values in between -1.1<ωq<-1/3 and follows the equation of state ωq=pressure(p)/energy density(ρq). This state parameter significantly affects the shape and size of the black hole shadow. We generalize all the geodesic equations of motion for ωq and obtain relation to visualize the black hole shadow by a static observer at any arbitrary distance in the domain of outer communication. We analytically estimate the black hole shadow observables: radius Rs, distortion parameter δs and the shadow area A. Using the numerical values of shadow radius Rs and area A, we obtain the angular diameter of the black hole shadow. The angular size of the M87 and Sgr A^* black holes are 42 ± 3 μa s and 48.7 ± 7 μa s respectively as observe by Event Horizon Telescope (EHT). In this case, the angular diameter of the black hole shadow increases with the quintessence parameter ωq and takes values θd ≈ 20 ± 3o with the parameter -0.66 ≤ ωq ≤ -0.62 for the static observer at ro=5M in the domain of outer communication.