Galactic black hole immersed in a dark halo with its surrounding thin accretion disk

TL;DR

This paper investigates how dark matter halos with tangential pressure influence the properties of accretion disks around Schwarzschild black holes, revealing increased luminosity and reduced stable orbit radii.

Contribution

It introduces an analytic model for black holes in dark matter halos with non-zero tangential pressure and analyzes its impact on accretion disk characteristics.

Findings

Tangential pressure decreases the innermost stable circular orbit radius.

Dark matter halos increase the luminosity of accretion disks.

The model differs from standard Schwarzschild black holes without dark matter.

Abstract

By considering the analytic, static and spherically symmetric solution for the Schwarzschild black holes immersed in dark matter fluid with non-zero tangential pressure \cite{Jusufi:2022jxu} and Hernquist-type density profiles \cite{Cardoso}, we compute the luminosity of accretion disk. We study the circular motion of test particles in accretion disk and calculate the radius of the innermost stable circular orbits. Using the steady-state Novikov-Thorne model we also compute the observational characteristics of such black hole's accretion disk and compare our results with the usual Schwarzschild black hole in the absence of dark matter fluid. We find that the tangential pressure plays a significant role in decreasing the size of the innermost stable circular orbits and thus increases the luminosity of black hole's accretion disk.