AstroAI Workshop 2026
Angelo Ricarte
Observational Signatures of Flux Eruption Events in Black Hole Accretion Flows
Presenter: Angelo Ricarte (Smithsonian Astrophysical Observatory)
Title: Observational Signatures of Flux Eruption Events in Black Hole Accretion Flows
Date/Time: Tuesday, June 16, 11:30 AM - 12:30 PM
Abstract: Black hole accretion flows with strong magnetic fields may exhibit “flux eruption events” (FEEs), transient and localized expulsions of matter near the event horizon due to magnetic reconnection. It is now possible to spatially resolve these events with the Event Horizon Telescope (EHT), a global network of millimeter-wave observatories that images black holes. Here, we use machine learning to characterize FEEs and determine observational signatures accessible to the EHT. First, we train a convolutional neural network to identify FEEs in uncorrupted simulated images. After using this network to label larger set of images, we train a random forest and perform logistic regressions to determine what observational signatures are associated with FEE. We find that during a FEE, images tend towards more diffuse emission, higher linear polarization, and lower total fluxes, but these trends are weak. In polarization, we find that the “Q-U’’ loop rotation rate decreases during FEEs, contrary to proposed models where FEEs simultaneously lead to both Q-U loops and flares. Our results imply that only high-resolution, high-dynamic range images would allow us to confidently detect FEEs and test the strong magnetic field hypothesis in this way.