http://arxiv.org/abs/1610.01607
We perform the first one-point fluctuation analysis of the high-energy neutrino sky. This method reveals itself to be especially suited to contemporary neutrino data, as it allows to study the properties of the astrophysical components of the high-energy flux detected by the IceCube telescope, even with low statistics and in the absence of point source detection. Besides the veto-passing atmospheric foregrounds, we adopt a simple modeling of the high-energy neutrino background by assuming two main extra-galactic components: star-forming galaxies and blazars. By leveraging multi-wavelength data from Herschel and Fermi, we predict the spectral and anisotropic probability distributions for their expected neutrino counts in IceCube. We find that star-forming galaxies are likely to remain a diffuse background due to poor angular resolution, and determine an upper limit on the number of shower events that can reasonably be associated to blazars. We also find that upper limits on the contribution of blazars to the measured flux are unfavourably affected by the skewness of their flux distribution. Our modeling suggests that blazars and star-forming galaxies can jointly explain only ~5 events of the 53 observed in the IceCube HESE data, leaving room for other astrophysical components at greater than 5 sigma significance in a one-point fluctuation analysis.
M. Feyereisen, I. Tamborra and S. Ando
Fri, 7 Oct 16
17/75
Comments: 35 pages, 6 figures, 3 tables
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