Towards VLBI Observations of Black Hole Structure

Understand

Black holes hold a tremendous discovery potential.

• In this paper the extent to which the Event Horizon Telescope and its next generation upgrade can resolve their structure is quantified.
• Black holes are characterized by a perfectly absorptive boundary, with a specific area determined by intrinsic parameters of the black hole.
• We use a general parametrization of spherically symmetric spacetimes describing deviations from this behavior, with parameters controlling the size of the central object and its interaction with light, in particular through a specular reflection coefficient $\Gamma$ and an intrinsic luminosity measured as a fraction $\eta$ of that of the accretion disc.