Black hole in the Dekel-Zhao dark matter profile

TL;DR

This paper derives a new black hole solution influenced by the Dekel-Zhao dark matter profile, showing how dark matter distribution affects black hole shadows and gravitational lensing, with implications for astrophysical observations.

Contribution

The paper introduces a novel black hole metric incorporating the Dekel-Zhao dark matter profile, analyzing its effects on photon dynamics and observable phenomena like shadows and lensing.

Findings

Black hole shadow radius increases with black hole mass.

Higher central dark matter density results in smaller shadows.

Dark matter profile parameters significantly influence gravitational lensing.

Abstract

Motivated by the work of Cardoso et al. [Phys. Rev. D 105 (2022) 6, L061501, https://doi.org/10.1103/PhysRevD.105.L061501] on black holes in galaxies, we derive a new black hole solution surrounded by a Dekel-Zhao (DZ) dark matter profile. The derived metric, influenced by DZ profile parameters, exhibits two distinct regimes: for $r \ll r_{\rm c}$ (\textcolor{black}{$r_{\rm c}$ is a characteristic radius}), exponential corrections dominate, producing significant deviations from the Schwarzschild solution near dense cores, while for $r \gg r_{\rm c}$, these corrections vanish, restoring the Schwarzschild metric at large distances. These findings ensure consistency with general relativity in vacuum. \textcolor{black}{The black hole shadow and deflection angle are analyzed, demonstrating that the shadow radius increases with black hole mass ($M_{\rm BH}$), while higher central densities ($\rho_{\rm ch}$) result in smaller shadows, reflecting the environmental impact of dense dark matter halos.} Photon dynamics reveal how DZ profiles modify critical impact parameters and effective potentials, with gravitational lensing effects highly sensitive to the characteristic radius ($r_{\rm c}$). Smaller $r_{\rm c}$ values lead to larger deflection angles due to stronger gravitational effects near compact cores. This work highlights the significance dark matter profiles in shaping black hole observables, providing a theoretical foundation for future observational studies and advancing the understanding of dark matter-black hole interactions in astrophysical and cosmological contexts.