The Role of Adaptive Ray Tracing in Analyzing Black Hole Structure

Abstract

The recent advent of the Event Horizon Telescope (EHT) has made direct imaging of supermassive black holes a reality. Simulated images of black holes produced via general relativistic ray tracing and radiative transfer provide a key counterpart to these observational efforts. Black hole images have a wide range of physically interesting image structures, ranging from extremely fine scales in their lensed "photon rings" to the very large scales in their relativistic jets. The multi-scale nature of the black hole system is therefore suitable for a multi-scale approach to generating simulated images that capture all key elements of the system. Here, we present a prescription for adaptive ray tracing, which enables efficient computation of extremely high resolution images of black holes. Using the polarized ray-tracing code ipole, we image a combination of semi-analytic and GRMHD models, and we show that images can be reproduced with mean squared error of less than 0.1% even after tracing 12x fewer rays. We then use adaptive ray tracing to explore properties of the photon ring. We illustrate the behavior of individual subrings in GRMHD simulations, and we explore their signatures in interferometric visibilities.

17 pages, 12 figures. Published in ApJ on May 3, 2021

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Cited by in corpus (15)

• The Black Hole Explorer: Motivation and Vision
• Toward determining the number of observable supermassive black hole shadows
• Photon ring test of the Kerr hypothesis: Variation in the ring shape
• Iharm3D: Vectorized General Relativistic Magnetohydrodynamics
• Self-lensing flares from black hole binaries I: general-relativistic ray tracing of black hole binaries
• Adaptive Analytical Ray Tracing of Black Hole Photon Rings
• Testing Gravity with Black Hole Shadow Subrings
• Blacklight: A General-Relativistic Ray-Tracing and Analysis Tool
• Study of relativistic accretion flow around KTN black hole with shocks
• Relativistic Signatures of Flux Eruption Events Near Black Holes
• First Space-VLBI Observations of Sagittarius A*
• Polarized signatures of adiabatically expanding hotspots in Sgr A*'s accretion flow
• Gravity versus astrophysics in black hole images and photon rings: Equatorial emissions and spherically symmetric space-times
• Prospects for ray-tracing light intensity and polarization in models of accreting compact objects using a GPU
• PATOKA: Simulating Electromagnetic Observables of Black Hole Accretion