Accretion disk luminosity for black holes surrounded by dark matter

TL;DR

This paper explores how dark matter influences the luminosity of black hole accretion disks, potentially altering mass estimates of supermassive black holes and offering insights into early universe observations.

Contribution

It demonstrates that dark matter can significantly modify accretion disk luminosity, affecting black hole mass estimations and providing a new perspective on early universe supermassive black holes.

Findings

Dark matter alters accretion disk luminosity.

Luminosity can be produced by smaller black holes with dark matter.

Implications for black hole mass estimation and early universe observations.

Abstract

We consider the observational properties of a static black hole space-time immersed in a dark matter envelope. We thus investigate how the modifications to geometry, induced by the presence of dark matter affect the luminosity of the black hole's accretion disk. We show that the same disk's luminosity produced by a black hole in vacuum may be produced by a smaller black hole if surrounded by dark matter under certain conditions. In particular, we demonstrate that the luminosity of the disk is markedly altered by dark matter's presence, suggesting that mass estimation of distant super-massive black holes may be changed if they are immersed in dark matter. We argue that a similar effect holds in more realistic scenarios and we discuss about the refractive index related to dark matter lensing. Hence we show how this may help explain the observed luminosity of super-massive black holes in the early universe.