We investigate whether reconnection of small-scale current sheets in transrelativistic supermassive black hole (SMBH) coronae can supply the nonthermal protons needed for high-energy neutrino emission, using NGC 1068 as a test case. We model the corona as a strongly turbulent, low-β, collisionless hydrogen plasma with characteristic size rco, magnetic field strength B, proton density np, and radiation energy density urad. Combining the observed IceCube-band neutrino luminosity with the X-ray luminosity and Thomson optical depth reduces these coronal quantities to a one-parameter family. Across this family, the proton magnetization σp≡B2/(4πnpmpc2) is transrelativistic with σp∼0.3. In this regime, we show that repeated encounters with intermittent reconnecting current sheets can energize suprathermal protons up to tens of PeV before photomeson cooling limits further acceleration. These injected particles may then be further processed by stochastic interactions with the turbulent cascade. Motivated by PIC simulations of strong turbulence at comparable magnetization, we adopt a nonthermal proton spectrum with an independently specified index and find that the predicted TeV spectral shape is broadly consistent with NGC~1068 without fitting the proton spectral slope.
@article{arxiv.2605.10559,
title = {Can magnetic reconnection power neutrino emission from AGN coronae?},
author = {Omar French and Gregory R. Werner and Mitchell C. Begelman},
journal= {arXiv preprint arXiv:2605.10559},
year = {2026}
}
Comments
11 pages, 3 figures, submitted to the Astrophysical Journal