On the angular distribution of IceCube high-energy events
  The detection of high-energy astrophysical neutrinos of extraterrestrial
origin by the IceCube neutrino observatory in Antarctica has opened a unique
window to the cosmos that may help to probe both the distant Universe and our
cosmic backyard. The arrival directions of these high-energy events have been
interpreted as uniformly distributed on the celestial sphere. Here, we revisit
the topic of the putative isotropic angular distribution of these events
applying Monte Carlo techniques to investigate a possible anisotropy. A modest
evidence for anisotropy is found. An excess of events appears projected towards
a section of the Local Void, where the density of galaxies with radial
velocities below 3000 km/s is rather low, suggesting that this particular group
of somewhat clustered sources are located either very close to the Milky Way or
perhaps beyond 40 Mpc. The results of further analyses of the subsample of
southern hemisphere events favour an origin at cosmological distances with the
arrival directions of the events organized in a fractal-like structure.
Although a small fraction of closer sources is possible, remote hierarchical
structures appear to be the main source of these very energetic neutrinos. Some
of the events may have their origin at the IBEX ribbon.
