Speaker
Description
The origin of the highest energy (>100TeV) neutrinos is still highly debated. AGN jets are capable of accelerating hadrons to relativistic speeds, a necessary step for neutrino production in photohadronic processes. A dense photon field, such as UV emission line photons from the broad-line region, can serve as a sufficient target for photohadronic interactions to produce neutrinos. However, blazar jets can outshine these emission lines, making it difficult to identify a broad-line region even when it is present — as seen in several “transitional blazars” that are candidate neutrino emitters. We present a case study of two AGN, PKS 0446+112 and PKS 1217+02, spatially coincident with IceCube neutrino events. We follow up on these sources with multi-wavelength data from a joint target-of-opportunity program with Fermi, NuSTAR, and VERITAS, searching for lepto-hadronic signatures in their SEDs and evidence of a broad-line region. These signatures could indicate the dense target photon fields and jet hadrons needed to produce neutrinos, with the goal of identifying populations of AGN most suited to neutrino production.
| Collaboration(s) | VERITAS |
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