Millimetre and submillimetre observations are opening a new window into the innermost regions of accreting supermassive black holes. Breakthroughs with the Event Horizon Telescope (EHT), alongside observations with ALMA and other radio facilities, are transforming our ability to investigate the extreme environments where accretion, magnetic fields, and energetic particles shape the emission from active galactic nuclei (AGN). Connecting these observations with advances in theoretical modelling and numerical simulations offers new opportunities to understand how black holes accrete matter and release energy.
A central challenge is to establish the physical origin of the millimetre emission and its connection to the accretion flow, the X-ray-emitting corona, and relativistic jets. The conference will explore jet formation and launching, the formation and physics of black-hole coronae, and the relationship between these components. Particular attention will be given to coronal properties from the X-ray perspective, examining how X-ray spectroscopy, variability, and timing can constrain the temperature, optical depth, geometry, and location of the corona. Combining these diagnostics with radio and millimetre observations will help clarify the roles of magnetic fields, particle acceleration, and energy dissipation near black holes.
The meeting will bring together observers, theorists, and computational astrophysicists around three connected themes:
- Physical processes and theoretical modelling: jet formation and launching, corona formation and heating, plasma physics, particle acceleration, magnetic reconnection, and the coupling between accretion flows, coronae, and jets.
- Observational signatures and variability: coronal properties inferred from X-ray observations; coordinated radio, millimetre, and X-ray studies; polarisation and time-domain diagnostics; and broadband spectral modelling to constrain magnetic fields, particle populations, and emission mechanisms.
- Future opportunities: prospects for the next-generation EHT, the Square Kilometre Array (SKA), and the proposed Atacama Large Aperture Submillimeter Telescope (AtLAST), including new approaches to studying obscured accretion and black-hole growth across cosmic time.
The meeting aims to connect different communities to discuss about accretion, coronae, and jet models, develop strategies for coordinated observing campaigns, and establish priorities for future facilities.