2025-07-24 –, Main Room 4
The Event Horizon Telescope (EHT) produced the first image of the black hole shadow in 2019, and advancements in imaging algorithms have only improved performance since then. We present VLBISkyRegularizers.jl, a regularized maximum likelihood (RML) black hole imaging software. Based on the Bayesian imaging package Comrade.jl, we take full advantage of the Julia language to make VLBISkyRegularizers.jl faster and more modular and flexible than comparable RML packages.
This talk presents an implementation of regularized maximum likelihood (RML) imaging methods for radio interferometry, with the primary aim of imaging black holes with the Event Horizon Telescope (EHT) and its proposed successors, including the next-generation EHT and the Black Hole Explorer. While RML methods have been successfully utilized before, our package, VLBISkyRegularizers.jl, offers several advantages made possible by the Julia language.
VLBISkyRegularizers.jl is an extension of Comrade.jl, a Bayesian imaging software that already speeds up black hole imaging by multiple orders of magnitude using key Julia features and Enzyme automatic differentiation. We add RML capabilities to this growing software library. In addition to popular spatial regularizers and novel polarization regularizers which are built into the package, users are able to define their own regularizers, with gradients automatically calculated via Enzyme. Bayesian methods made easy by Julia also allow for more exhaustive searches of the cost function compared to gradient descent methods.
Within the larger EHT Julia Organization, simultaneous projects to perform multi-frequency imaging and dynamical imaging are paving the way for movies of black holes in multiple frequencies. Utilizing the composability of Julia, we will be able to perform spatio-temporal-spectral imaging in Bayesian and RML frameworks. While primarily developed for imaging black holes, these packages are widely applicable to radio interferometry on larger arrays as well.
Recent graduate of Yale University working on black hole imaging with the Event Horizon Telescope.