# Imaging Black Holes and Jets with a VLBI Array Including Multiple Space-Based Telescopes

## TL;DR

This paper demonstrates that adding space-based telescopes to ground VLBI arrays significantly enhances imaging resolution, enabling detailed observation of black hole shadows and jet structures, advancing our understanding of black hole physics.

## Contribution

It explores the benefits of incorporating space telescopes into VLBI arrays, showing improved resolution and image fidelity for black hole and jet studies.

## Key findings

- High-fidelity images resolving 3 microarcsecond shadows are achievable.
- Space VLBI improves understanding of jet launching mechanisms.
- Enhanced resolution aids in studying black hole and jet substructures.

## Abstract

Very long baseline interferometry (VLBI) from the ground at millimeter wavelengths can resolve the black hole shadow around two supermassive black holes, Sagittarius A* and M87. The addition of modest telescopes in space would allow the combined array to produce higher-resolution, higher-fidelity images of these and other sources. This paper explores the potential benefits of adding orbital elements to the Event Horizon Telescope. We reconstruct model images using simulated data from arrays including telescopes in different orbits. We find that an array including one telescope near geostationary orbit and one in a high-inclination medium Earth or geosynchronous orbit can succesfully produce high-fidelity images capable of resolving shadows as small as 3 microarcseconds in diameter. One such key source, the Sombrero Galaxy, may be important to address questions regarding why some black holes launch powerful jets while others do not. Meanwhile, higher-resolution imaging of the substructure of M87 may clarify how jets are launched in the first place. The extra resolution provided by space VLBI will also improve studies of the collimation of jets from active galactic nuclei.