THE ICECUBE EVENT

• 2017 September 22. The IceCube Observatory detects a high energy neutrino and reconstruct its energy (~290 TeV) and arrival direction.

• 2017 September 22, 43'' later. The IceCube Observatory alerts the astronomical community of the direction of the neutrino.

• 2017 September 28. The Fermi LAT Collaboration reports that the direction of origin of IceCube-170922A was consistent, within 0.06°, with a known γ-ray source in a state of enhanced emission: the Blazar TXS 0506+056. [The green square in the image on the right represents the neutrino direction reconstructed by IceCube, the image in background the γ-rays direction detected by Fermi LAT (A) and MAGIC (B)]

• 2018 July. The IceCube Collaboration reports the detection of a high-energy neutrino by IceCube and the multi-wavelength/multi-instrument observations of a flaring γ-ray blazar, TXS 0506+056, which was found to be positionally coincident with the neutrino direction. Chance coincidence of the IceCube-170922A event with the flare of TXS 0506+056 is statistically disfavored at the level of 3σ [99.7 %] (from "Multi-messenger observations of a flaring blazar coincident with high-energy neutrino IceCube-170922")

• 2018 July. An association of observed astrophysical neutrinos with blazars would therefore imply that high-energy protons or nuclei up to energies of at least tens of PeV (10^15 eV) are produced in blazar jets, suggesting that they may be the birthplaces of the most energetic particles observed in the Universe, the ultra-high energy cosmic rays. (from "Multi-messenger observations of a flaring blazar coincident with high-energy neutrino IceCube-170922")