Saved in:
Bibliographic Details
Main Authors: Luo, Zuting, Tang, Meirong, Xu, Zhaoyi
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2505.20115
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866909848900206592
author Luo, Zuting
Tang, Meirong
Xu, Zhaoyi
author_facet Luo, Zuting
Tang, Meirong
Xu, Zhaoyi
contents This paper investigates the optical appearance of a Schwarzschild-like black hole (BH) surrounded by a Dehnen-(1, 4, 5/2) type dark matter (DM) halo, with a focus on how the DM halo's density $ρ_{s}$ and radius $r_{s}$ influence the BH's shadow and photon ring. First, the radius $r_h$ of the BH's event horizon and the equation of motion for photons were derived, and observational data from the Event Horizon Telescope (EHT) for M87* were used to constrain the parameters $ρ_{s}$ and $r_{s}$ of the DM halo. Afterward, by varying the values of $ρ_{s}$ and $r_{s}$, key parameters such as the effective potential $V_{eff}$ of photons, the critical impact parameter $b_{ph}$, the radius $r_{isco}$ of the innermost stable circular orbit, and the radius $r_{ph}$ of the photon sphere were calculated for each case. It was found that as $ρ_{s}$ and $r_{s}$ increase, the above mentioned parameters all show an increasing trend. Subsequently, we investigated the optical appearance of the BH illuminated by two types of accretion models: optically and geometrically thin disk models and spherical accretion models. The findings indicate that as $ρ_{s}$ and $r_{s}$ increase, the peak of the received intensity shifts toward a higher impact parameter $b$, resulting in a distinct optical appearance.
format Preprint
id arxiv_https___arxiv_org_abs_2505_20115
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Shadows and Observational Images of a Schwarzschild-like Black Hole Surrounded by a Dehnen-type Dark Matter Halo
Luo, Zuting
Tang, Meirong
Xu, Zhaoyi
General Relativity and Quantum Cosmology
This paper investigates the optical appearance of a Schwarzschild-like black hole (BH) surrounded by a Dehnen-(1, 4, 5/2) type dark matter (DM) halo, with a focus on how the DM halo's density $ρ_{s}$ and radius $r_{s}$ influence the BH's shadow and photon ring. First, the radius $r_h$ of the BH's event horizon and the equation of motion for photons were derived, and observational data from the Event Horizon Telescope (EHT) for M87* were used to constrain the parameters $ρ_{s}$ and $r_{s}$ of the DM halo. Afterward, by varying the values of $ρ_{s}$ and $r_{s}$, key parameters such as the effective potential $V_{eff}$ of photons, the critical impact parameter $b_{ph}$, the radius $r_{isco}$ of the innermost stable circular orbit, and the radius $r_{ph}$ of the photon sphere were calculated for each case. It was found that as $ρ_{s}$ and $r_{s}$ increase, the above mentioned parameters all show an increasing trend. Subsequently, we investigated the optical appearance of the BH illuminated by two types of accretion models: optically and geometrically thin disk models and spherical accretion models. The findings indicate that as $ρ_{s}$ and $r_{s}$ increase, the peak of the received intensity shifts toward a higher impact parameter $b$, resulting in a distinct optical appearance.
title Shadows and Observational Images of a Schwarzschild-like Black Hole Surrounded by a Dehnen-type Dark Matter Halo
topic General Relativity and Quantum Cosmology
url https://arxiv.org/abs/2505.20115