Today's Colloquium: AGN jets and neutrinos: multimessenger studies of blazars

Image may be NSFW.
Clik here to view.© Kadler M, Krauss F et al., Nature Physics 12, 807

Active galaxies harbor a supermassive black hole at their center. They often show perpendicular outflows of matter, called jets, which might contribute to the observed cosmic rays and neutrinos. The IceCube collaboration has detected an extraterrestrial neutrino flux with the most significant signal in the southern sky at PeV energies.

We show that AGN jets are able to produce the observed neutrino flux using multiwavelength data. We further find that a major outburst of a single blazar is in spatial and temporal consistency with the 2 PeV IceCube neutrino event. The energy output of PKS B1424-418 alone can explain the neutrino event, indicative of a physical association. We further studied simultaneous radio to gamma-ray SEDs from the TANAMI sample.

This large data set allows us to address key questions in AGN jet physics like the blazar sequence, jet-emission models and the fundamental plane of black hole masses.