Observational properties of a Schwarzschild black hole surrounded by a Dehnen-type dark matter halo

TL;DR

This paper explores how a Dehnen-type dark matter halo influences the accretion disk properties and observational signatures around a Schwarzschild black hole, revealing that increased dark matter density dims and cools the disk.

Contribution

It provides the first detailed analysis of the impact of Dehnen-type dark matter halos on black hole accretion disk observables and image profiles.

Findings

Disk temperature and flux decrease with higher DM density and radius.

Dark matter halos cause the accretion disk to appear dimmer and colder.

Image profiles are significantly affected by DM parameters and inclination angle.

Abstract

This study investigates the accretion process and observational signatures of thin accretion disks around a Schwarzschild black hole (BH) embedded in a Dehnen-type dark matter (DM) halo. We examine the influence of the density {\rho}_{s} and radius r_{s} of the DM halo on key disk properties, including the energy flux, temperature distribution, and emission spectrum. Our results show that all three of these quantities decrease with increasing {\rho}_{s} or r_{s}. Furthermore, by generating and analyzing both direct and secondary images of the accretion disk, we explore how the observational inclination angle and the DM halo parameters {\rho}_{s} and rs affect image profiles. Finally, the observed flux distributions are presented for different inclination angles. Our findings indicate that the accretion disk becomes colder and dimmer as the DM halo parameters increase, highlighting the significant role of DM in shaping BH observables.