IceCube Discovers Neutrino Emission Inside Milky Way

Data from the IceCube Neutrino Observatory – a cubic-kilometer particle detector built deep within Antarctic ice – reveals high-energy neutrino emission from within the Milky Way, according to a new study. "Confirming the existence of this long-sought signal paves the way for the future of astroparticle physics in our galaxy," writes Luigi Antonio Fusco in a related Perspective. Observations of high-energy neutrinos have shown that they mostly originate from extragalactic sources, such as active galaxies far outside our own. Gamma ray observations show bright emissions from within the Galactic plane of the Milky Way. Since gamma rays and neutrinos are thought to be produced by the same astrophysical processes, the Milky Way's galactic plane is an expected location of neutrino emission. However, previous searches for this intragalactic signal using neutrino detectors have not provided conclusive evidence that such a signal exists. By applying machine learning techniques to 10 years of data from the IceCube Neutrino Observatory in Antarctica, researchers from the IceCube Collaboration report the first statistically robust evidence for neutrinos emission from the inner parts of the Milky Way. According to the authors, the observed excess of neutrinos from the Galactic plane provides evidence that the Milky Way is a source of high-energy neutrinos and is consistent with the distribution and expected interactions of cosmic rays within the Galaxy.