Advancing Black Hole Imaging with Space-Based Interferometry

TL;DR

This paper explores the potential of space-based VLBI to improve black hole imaging beyond current ground-based limits, identifying optimal configurations and key metrics for future missions.

Contribution

It introduces a design framework for a space-based interferometry array with specific orbit configurations to enhance black hole imaging capabilities.

Findings

Optimal array configuration involves two high Earth orbit satellites with non-coplanar, counter-rotating orbits.

Key metrics identified predict image fidelity and scientific potential for mission optimization.

Analysis demonstrates improved imaging of black hole shadows and plasma dynamics with proposed space-based setup.

Abstract

Horizon-scale imaging with the Event Horizon Telescope (EHT) has provided transformative insights into supermassive black holes but its resolution and scope are limited by ground-based constraints such as the size of the Earth, its relatively slow rotation, and atmospheric delays. Space-based very long baseline interferometry (VLBI) offers the capability for studying a larger and more diverse sample of black holes. We identify a number of nearby supermassive black holes as prime candidates for horizon-scale imaging at millimeter wavelengths, and use source characteristics such as angular size, sky distribution, and variability timescales to shape the design of a space-based array. We identify specific metrics that serve as key predictors of image fidelity and scientific potential, providing a quantitative basis for optimizing mission design parameters. Our analysis demonstrates that the optimal configuration requires two space-based elements in high Earth orbits (HEO) that are not coplanar and are apparently counter-rotating. Our results delineate the key requirements for a space-based VLBI mission, enabling detailed studies of black hole shadows, plasma dynamics, and jet formation, advancing black hole astrophysics beyond the current capabilities of the EHT.