A Sharper Look at the M87 Black Hole with PRIMO

The Event Horizon Telescope (EHT) is a very long baseline interferometer incorporating several radio telescopes spread all over the world.  The sparse interferometric coverage of the Event Horizon Telescope makes reconstruction of black-hole images challenging.  Principal component interferometric modeling (PRIMO) is a new algorithm for image reconstruction that builds a principal components basis from high-fidelity general relativistic, magnetohydrodynamic (GRMHD) simulations of low-luminosity accretion flows.  This allows us to reconstruct images at are both consistent with the interferometric data and that live in the space spanned by the simulations.  The algorithm follows Monte Carlo Markov Chains to fit a linear combination of principal components to EHT interferometric observations.  PRIMO can effeciently and accurately reconstruct simulated EHT data sets for several simulated images, even when the simulations are significantly different from those in the training set.  I will discuss the algorithm itself, its application to synthetic data, and show a new image of M87 published in April, 2023.

Speaker: Lia Medeiros, Princeton University