http://arxiv.org/abs/1806.04769
We study if the diffuse astrophysical neutrino flux can come from blazar jets — a subclass of Active Galactic Nuclei (AGNs) — while at the same time respecting the blazar stacking limit based on source catalogs. We compute the neutrino flux from resolved and unresolved sources using an averaged, empirical relationship between electromagnetic spectrum and luminosity, known as the {\em blazar sequence}, for two populations of blazars (BL Lacs and FSRQs). Using a source model with realistic neutrino flux computations, we demonstrate that blazars can indeed power the diffuse neutrino flux and obey the stacking limit at the same time, and we derive the conditions for the baryonic loading (proton versus $\gamma$-ray luminosity) evolving over the blazar sequence. Under the hypothesis that blazars power the diffuse astrophysical neutrino flux, we find that the dominant contribution of the diffuse flux up to PeV energies must come from unresolved BL Lacs with baryonic loadings larger than about $10^4$. A small contribution of resolved high-luminosity FSRQs with baryonic loadings of order $10^2$ can contribute at the highest energies, which is, however, directly tested by the stacking limit. Our results are roughly consistent with the expectations for AGN energetics and have implications for radiation models for AGNs.
A. Palladino, X. Rodrigues and W. Winter
Thu, 14 Jun 18
7/49
Comments: 11 pages + 4 pages of Appendix