  The recent discovery of astrophysical neutrinos from the Seyfert galaxy NGC
1068 suggests the presence of non-thermal protons within a compact "coronal"
region close to the central black hole. The acceleration mechanism of these
non-thermal protons remains elusive. We show that a large-scale magnetic
reconnection layer, of the order of a few gravitational radii, may provide such
a mechanism. In such a scenario, rough energy equipartition between magnetic
fields, X-ray photons, and non-thermal protons is established in the
reconnection region. Motivated by recent three-dimensional particle-in-cell
simulations of relativistic reconnection, we assume that the spectrum of
accelerated protons is a broken power law, with the break energy being
constrained by energy conservation (i.e., the energy density of accelerated
protons is at most comparable to the magnetic energy density). The proton
spectrum is $dn_p/dE_p\propto E_p^{-1}$ below the break, and $dn_p/dE_p\propto
E_p^{-s}$ above the break, with IceCube neutrino observations suggesting $s
\simeq 3$. Protons above the break lose most of their energy within the
reconnection layer via photohadronic collisions with the coronal X-rays,
producing a neutrino signal in good agreement with the recent observations.
Gamma-rays injected in photohadronic collisions are cascaded to lower energies,
sustaining the population of electron-positron pairs that makes the corona
moderately Compton thick.
