AGILE Detection of Gamma-Ray Sources Coincident with Cosmic Neutrino Events

Lucarelli, F.; Tavani, M.; Piano, G.; Bulgarelli, A.; Donnarumma, I.; Verrecchia, F.; Pittori, C.; Antonelli, L. A.; Argan, A.; Barbiellini, G.; Caraveo, P.; Cardillo, M.; Cattaneo, P. W.; Chen, A.; Colafrancesco, S.; Costa, E.; Monte, E. Del; Cocco, G. Di; Ferrari, A.; Fioretti, V.; Galli, M.; Giommi, P.; Giuliani, A.; Lipari, P.; Longo, F.; Mereghetti, S.; Morselli, A.; Paoletti, F.; Parmiggiani, N.; Pellizzoni, A.; Picozza, P.; Pilia, M.; Rappoldi, A.; Trois, A.; Ursi, A.; Vercellone, S.; Vittorini, V.

doi:10.3847/1538-4357/aaf1c0

The origin of cosmic neutrinos is still largely unknown. Using data obtained by the gamma-ray imager on board the Astro-rivelatore Gamma a Immagini Leggero (AGILE) satellite, we systematically searched for transient gamma-ray sources above 100 MeV that are temporally and spatially coincident with 10 recent high-energy neutrino IceCube events. We found three AGILE candidate sources that can be considered possible counterparts to neutrino events. Detecting three gamma-ray/neutrino associations out of 10 IceCube events is shown to be unlikely due to a chance coincidence. One of the sources is related to the BL Lac source TXS 0506+056. For the other two AGILE gamma-ray sources there are no obvious known counterparts, and both Galactic and extragalactic origin should be considered.