91ÅÝܽ

Synopsis

Below the geographic South Pole, the IceCube project has transformed one cubic kilometer of natural Antarctic ice into a neutrino detector. IceCube detects more than 100,000 neutrinos per year in the GeV to 10 PeV energy range. Among those, we have isolated a flux of high-energy neutrinos originating beyond our Galaxy, with an energy flux that is comparable to that of the extragalactic high-energy gamma-ray flux observed by astronomers. With a decade of data, we have identified their first sources, which point to the obscured dense cores associated with the supermassive black holes at the centers of active galaxies as the origin of high-energy neutrinos and high-energy cosmic rays. We recently also observed neutrinos originating in our own Milky Way which is, interestingly, not a prominent feature in the neutrino sky.