Speaker
Description
Several theoretical models explain the neutrino flux from Active Galactic Nuclei, such as NGC 1068, as originating from cosmic-ray interactions in the corona. If cosmic rays are destroyed in such dense environments, a natural question arises: where do the observed Ultra-High-Energy Cosmic Rays (UHECR) originate? In this contribution, we explore the possibility that UHECRs originate in transparent environments with low accretion rates. First, we show that horizon-scale magnetic fields threading supermassive black holes (SMBHs), limited only by gravity, can accelerate particles to the highest detected energies and beyond. Subsequently, we build a realistic parameter space in which the environment surrounding the SMBH is transparent enough to allow the primaries to escape, while the magnetic fields remain strong enough to accelerate to Ultra-High-Energies. Finally, we test this hypothesis on UHECR data from the Pierre Auger Observatory by performing a correlation analysis with a list of nearby galaxies with reliably measured masses, differentiating between AGN and quiescent hosts. The analysis shows marginal excesses that are compatible with the background after accounting for the look-elsewhere effect. Nevertheless, the presented framework provides a link between black-hole physics and the maximum energies of cosmic particles and defines concrete observational tests for next-generation UHECR datasets.
