AI Insight
This paper discusses how the Square Kilometre Array (SKA) telescope and its Very Long Baseline Interferometry (VLBI) capabilities will advance the study of radio-quiet active galactic nuclei (AGN), which comprise the majority of AGN but lack prominent radio jets. The SKA will provide unprecedented sensitivity and resolution to distinguish between various radio emission sources in these systems, including star formation, AGN-driven winds, weak jets, and coronal activity near supermassive black holes. At full deployment, SKA-MID integrated into global VLBI networks will achieve sub-milliarcsecond resolution with microjansky sensitivity across 0.35-15 GHz, enabling the first comprehensive survey of radio-quiet AGN nuclei from nearby galaxies to the early universe.
Why it matters
Understanding radio-quiet AGN is crucial for explaining how supermassive black holes affect galaxy evolution through feedback processes. The SKA's capabilities will resolve longstanding questions about accretion and ejection mechanisms in the dominant population of active galaxies, providing insights into fundamental processes that shape cosmic structure formation.
Understand the Science
arXiv:2606.30307v1 Announce Type: new
Abstract: The accretion-ejection mechanism in Active Galactic Nuclei (AGN) remains a central open problem in astrophysics, tied to the role of AGN feedback in galaxy formation and evolution. Radio-quiet AGN dominate the observed AGN population. Lacking luminous jets, their radio emission traces a rich set of processes spanning the host galaxy kpc scales down to the vicinity of the supermassive black hole: star formation, AGN-driven winds and shocks, free-free emission from photo-ionized gas, low-power jets, and coronal activity close to the inner accretion disk. The Square Kilometre Array (SKA) will probe these processes across a wide frequency range with unprecedented sensitivity, wide-field survey capability, and, critically, high-resolution VLBI imaging. Flux, spectral, and polarization monitoring will constrain dynamics and environmental coupling, while mapping nuclear regions on sub-pc to kpc scales will disentangle compact cores from host emission, resolving the diversity of radio activity across accretion regimes and jet powers from the local Universe to the cosmic dawn. At the full AA4 deployment, the SKA-MID phased into global VLBI arrays will deliver sub-milliarcsecond imaging and $mu$Jy sensitivity over 0.35–15,GHz, enabling the first population-level census of radio-quiet AGN nuclei. Earlier AA$ast$ operations will support pilot studies of the brightest nearby systems.