The immediate environment of an astrophysical black hole

TL;DR

This paper discusses the immediate environment of astrophysical black holes in light of upcoming EHT observations, highlighting potential physical processes and questioning simulation approximations.

Contribution

It predicts observable phenomena near black holes and critiques common simulation assumptions, aiding interpretation of future EHT data.

Findings

Prediction of dynamic pair formation above the horizon

Identification of electromagnetic energy dissipation along jet boundaries

Recognition of a weak magnetic field region separating jet and disk wind

Abstract

In view of the upcoming observations with the Event Horizon Telescope (EHT), we present our thoughts on the immediate environment of an astrophysical black hole. We are concerned that two approximations used in general relativistic magnetohydrodynamic numerical simulations, namely numerical density floors implemented near the base of the black hole jet, and a magnetic field that comes from large distances, may mislead our interpretation of the observations. We predict that three physical processes will manifest themselves in EHT observations, namely dynamic pair formation just above the horizon, electromagnetic energy dissipation along the boundary of the black hole jet, and a region of weak magnetic field separating the black hole jet from the disk wind.