Interpretation of the coincident neutrino observation and a bright flare from blazar TXS0506+056
On September 22nd 2017, the IceCube Neutrino Observatory reported a muon track from a neutrino with a very good positional accuracy. The alert triggered a number of astronomical follow-up campaigns, and the Fermi gamma-ray telescope found as counterpart an object named TXS0506+056 in a very bright, flaring state; this observation may be the first direct evidence for an extragalactic source of very high-energy cosmic rays. Here we perform a detailed time-dependent modeling of these relevant processes and present a self-consistent model for the source. We find a slow but over-proportional response of the neutrino flux during the flare compared to the production enhancement of energetic cosmic rays. We also demonstrate that energetic cosmic-ray ions, which produce the neutrinos, provide emission in the hard X-ray band and, to a lesser degree, in TeV gamma rays, whereas optical photons and GeV-scale gamma rays are predominantly radiated by electrons. Our results indicate that especially future X-ray and TeV-scale gamma-ray observations of nearby objects can be used to identify more such events.