The Black Hole Explorer: Using the Photon Ring to Visualize Spacetime Around the Black Hole

TL;DR

This paper introduces the Black Hole Explorer (BHEX), a space-based telescope system designed to visualize the photon ring around supermassive black holes, enhancing understanding of spacetime geometry through simulated photon trajectories.

Contribution

The paper presents the design and purpose of BHEX and explores photon ring visualization techniques to better understand black hole spacetime geometry.

Findings

Simulated photon trajectories around spinning black holes.

Insights into the flow of light near black holes.

Potential for improved black hole imaging.

Abstract

The Black Hole Explorer (BHEX), an orbiting, multi-band, millimeter radio-telescope, in hybrid combination with millimeter terrestrial radio-telescopes, is designed to discover and measure the thin photon ring around the supermassive black holes M87* and Sgr A*. As background to the BHEX instruments, this paper explores various aspects of the photon ring, focusing on the intricate flow of light around a spinning black hole, and tracking, through visual simulations, photons as they course along geodesics. Ultimately, the aim of these visualizations is to advance the foundational aims of the BHEX instrument, and through this experiment to articulate spacetime geometry via the photon ring.