Project Description
Seyfert galaxies have become an important piece of the puzzle in high-energy astrophysics. NGC 1068 is the first candidate neutrino source detected at \(4.2\,\sigma\) level. A first stacking analysis for southern sources show evidence that also other Seyferts emit neutrinos. Including neutrinos in the multimessenger modeling of the sources has improved our understanding of the emission region significantly: The neutrino flux of NGC 1068 at TeV energies exceeds the observed gamma-ray upper limits at these energies by more than an order of magnitude, suggesting that neutrino production in NGC 1068 occurs in a region close to the black hole, the so-called AGN corona. This region is opaque to gamma-rays co-produced with the high-energy neutrinos.In Phase 1, we disentangled the star-forming and the AGN activity of NGC 1068: we were the first to explain its Fermi gamma-ray emission by the surrounding starburst ring, showed that its jet is not powerful enough, and confirmed that the neutrinos originate from the corona close to the black hole. We also developed an analytical model for stochastic acceleration in weakly turbulent environments to validate our 3D propagation code.
In Phase 2 we focus on the modeling of the central region of an active galactic nucleus (AGN), that allows for spatial variation, and the analysis of a large multimessenger sample of Seyfert galaxies, to address the following three research questions:
- What is the impact of a spatially varying AGN corona on the non-thermal emission signals?
- How to develop a neutrino stacking analysis that incorporates uncertainties based on the individual multi-wavelength data of the considered sources?
- How much can the whole population of Seyfert galaxies contribute to the diffuse neutrino flux?
