On the Origin of High Energy Neutrinos from NGC 1068: The Role of Non-Thermal Coronal Activity

TL;DR

This paper proposes that high-energy neutrinos from NGC 1068 originate near its supermassive black hole, with coronal activity explaining the emission, which aligns with observed spectral features but cannot be confirmed via current gamma-ray observations.

Contribution

The study introduces a model linking coronal activity around the black hole to neutrino emission in NGC 1068, consistent with spectral data and providing testable predictions for future MeV gamma-ray observations.

Findings

Neutrino emission likely produced near the supermassive black hole

Coronal parameters match observed spectral excess

Gamma-ray attenuation prevents current verification in GeV/TeV bands

Abstract

NGC 1068, a nearby type-2 Seyfert galaxy, is reported as the hottest neutrino spot in the 10-year survey data of IceCube. Although there are several different possibilities for the generation of high-energy neutrinos in astrophysical sources, feasible scenarios allowing such emission in NGC 1068 have not yet been firmly defined. We show that the flux level of GeV and neutrino emission observed from NGC 1068 implies that the neutrino emission can be produced only in the vicinity of the supermassive black hole in the center of the galaxy. The coronal parameters, such as magnetic field strength and corona size, making this emission possible are consistent with the spectral excess registered in the millimeter range. The suggested model and relevant physical parameters are similar to those revealed for several nearby Seyferts. Due to the internal gamma-ray attenuation, the suggested scenario cannot be verified by observations of NGC 1068 in the GeV and TeV gamma-ray energy bands. However, the optical depth is expected to become negligible for MeV gamma rays, thus future observations in this band will be able to prove our model.