Interpreting the high-energy neutrino sky through an angular power spectrum analysis

The origin of high-energy neutrinos, observed in the last 10 years by IceCube, is unknown. We gain more insight by studying the expected angular distribution of potential source populations, considering that IceCube observes a neutrino sky consistent with an isotropic distribution.rnWe simulate neutrino skymaps by applying statistical distributions for the fluxes of extra-galactic sources and investigate the sensitivities of current (IceCube) and future (IceCube-Gen2 and KM3NeT) experiments. I will show that the angular power spectrum is a powerful probe to assess the angular characteristics of neutrino data and demonstrate that we can constrain rare and bright source classes with current IceCube data.rnAnother potential source is the decay or annihilation of dark matter, suggested by the observed excess in the High-Energy-Starting-Event (HESE) data set of IceCube. These neutrinos are expected to correlate with the galactic centre, allowing us to distinguish between dark matter and astrophysical origin. We apply the angular power spectrum analysis to the HESE data, and set model-independent limits on dark matter properties. This method relies only on the angular distribution of neutrino events and is therefore stable against astrophysical uncertainties.rnMoreover we perform a sensitivity forecast for IceCube-Gen2 and KM3NeT exposure for different decaying and annihilating channels. KM3NeT is especially sensitive to low dark matter masses due to its visibility towards the galactic centre. We therefore extend to masses above 100 GeV, and find that even at lower energies, the angular power spectrum analysis offers a robust way to interpret the neutrino sky.

Authors: Ariane Dekker
Co-Authors: Marco Chianese | Shin'ichiro Ando
Indico-ID: 1370
Proceeding URL: https://pos.sissa.it/395/1198

Discussion timeslot (ZOOM-Meeting): 16. July 2021 - 18:00ZOOM-Meeting URL: https://icrc2021.desy.de/pf_access_abstractsCorresponding Session: https://icrc2021-venue.desy.de/channel/Presenter-Forum-1-Evening-All-Categories/48