The Black Hole Explorer: Photon Ring Science, Detection and Shape Measurement

Abstract

General relativity predicts that black hole images ought to display a bright, thin (and as-of-yet-unresolved) ring. This "photon ring" is produced by photons that explore the strong gravity of the black hole, flowing along trajectories that experience extreme light bending within a few Schwarzschild radii of the horizon before escaping. The shape of the photon ring is largely insensitive to the precise details of the emission from the astronomical source surrounding the black hole and therefore provides a direct probe of the Kerr geometry and its parameters. The Black Hole Explorer (BHEX) is a proposed space-based experiment targeting the supermassive black holes M87* and Sgr A* with radio-interferometric observations at frequencies of 100 GHz through 300 GHz and from an orbital distance of ~30,000 km. This design will enable measurements of the photon rings around both M87* and Sgr A*, confirming the Kerr nature of these sources and delivering sharp estimates of their masses and spins.

Submitted to SPIE Space Telescopes & Instrumentation

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Cited by in corpus (20)

• The Black Hole Explorer: Motivation and Vision
• Towards a Non-singular Paradigm of Black Hole Physics
• WGC as WCCC protector: The Synergistic Effects of various Parameters in Identifying WGC candidate Models
• The future ability to test theories of gravity with black-hole shadows
• Gravitational lensing and accretion disk imaging of a Buchdahl dense core
• Multi-Frequency Models of Black Hole Photon Rings from Low-Luminosity Accretion Disks
• Perturbative and non-linear analyses of gravitational turbulence in spacetimes with stable light rings
• Black hole photon ring beyond General Relativity: an integrable parametrization
• Inferring Black Hole Spin from Interferometric Measurements of the First Photon Ring: A Geometric Approach
• The Black Hole Explorer: Using the Photon Ring to Visualize Spacetime Around the Black Hole
• Spacetime Measurements with the Photon Ring
• Ultra-low noise laser and optical frequency comb-based timing system for the Black Hole Explorer (BHEX) mission
• The Japanese Vision for the Black Hole Explorer Mission
• Morphology of Relativistically Broadened Line Emission from Axisymmetric Equatorial Accretion Disks
• Non-thermal Synchrotron Emission and Polarization Signatures during Black Hole Flux Eruptions
• A General Discussion on Photon Spheres in Different Categories of Spacetimes
• Neutral particle collisions near Gibbons-Maeda-Garfinkle-Horowitz-Strominger black holes after shadow observations
• Limiting the Yukawa Gravity through the Black Hole Shadows of Sgr A* and M87*
• Exploring black holes with multiple photon spheres by interferometric signatures
• Polarization Signatures of Inspiraling Hotspots around Kerr Black Holes