Finally a hundred years after the discovery of cosmic-rays, a blazar has been identified as a source (at ~3 sigma level) of high-energy neutrinos and cosmic-rays thanks to the real-time multimessenger observation lead by the cubic-kilometer IceCube neutrino observatory. In this talk, details of the spatial-timing correlation analysis of the ~290 TeV neutrino event with Fermi light curves will be presented.
The second part of the talk will be dedicated to the searches for the highest energy neutrinos of all flavours with IceCube. In particular, results on the Glashow resonance and implications for the neutrino diffuse spectrum will be shown for the first time. The early-muons originated from hadronic shower generated via Glashow resonance decay could be used to improve cascade direction resolution. Possible sources of the Glashow candidate will be introduced.