Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Modelling the coincident observation of a high-energy neutrino and a
  bright blazar flare   In September 2017, the IceCube Neutrino Observatory recorded a
very-high-energy neutrino in directional coincidence with a blazar in an
unusually bright gamma-ray state, TXS0506+056. Blazars are prominent photon
sources in the universe because they harbor a relativistic jet whose radiation
is strongly collimated and amplified. High-energy atomic nuclei known as cosmic
rays can produce neutrinos; thus the recent detection may help identifying the
sources of the diffuse neutrino flux and the energetic cosmic rays. Here we
report on a self-consistent analysis of the physical relation between the
observed neutrino and the blazar, in particular the time evolution and spectral
behavior of neutrino and photon emission. We demonstrate that a moderate
enhancement in the number of cosmic rays during the flare can yield a very
strong increase of the neutrino flux which is limited by co-produced hard
X-rays and TeV gamma rays. We also test typical radiation models for
compatibility and identify several model classes as incompatible with the
observations. We investigate to what degree the findings can be generalized to
the entire population of blazars, to determine the relation between their
output in photons, neutrinos, and cosmic rays, and suggest how to optimize the
strategy of future observations.

27
The categories of this paper are: comp-gas
15
The categories of this paper are: nucl-ex
20
The categories of this paper are: acc-phys
33
The categories of this paper are: plasm-ph
31
The categories of this paper are: ao-sci
34
The categories of this paper are: chem-ph
26
The categories of this paper are: bayes-an
37
The categories of this paper are: supr-con
14
The categories of this paper are: math-ph
11
The categories of this paper are: hep-lat
21
The categories of this paper are: adap-org
19
The categories of this paper are: eess
23
The categories of this paper are: solv-int
9
The categories of this paper are: nlin
28
The categories of this paper are: alg-geom
18
The categories of this paper are: econ