Reacción a "Reactions to the discovery of high-energy neutrinos emitted by an active galaxy"

The IceCube neutrino observatory, in operation since 2010 at the South Pole, has succeeded in identifying the active galaxy NGC1068 as a source of high-energy astrophysical neutrinos.   

This is an extremely important result that definitively opens the door to neutrino astronomy (and with it to what is known as multi-messenger astronomy), already inaugurated by the IceCube experiment itself in 2018 after associating for the first time the emission of this type of neutrino with an astrophysical object known for its emissions of electromagnetic radiation, such as radio waves or gamma rays. On that occasion, the source was the blazar TXS 0506+056 and it was possible to associate the emission of a single high-energy neutrino, while now it is the galaxy NGC1068, to which it has been possible to link the origin of about 80 neutrinos. In both cases these are active galaxies in which the production of radiation would be due to the fall of material onto a supermassive black hole and where the high density of dust and gas in the central part would make the emission of electromagnetic radiation difficult. Neutrinos, on the other hand, due to their weak interaction with matter could escape even from the densest environments without any problem, providing valuable information about the processes taking place in the vicinity of supermassive black holes. Moreover, their straight-line propagation, unlike in the case of cosmic rays, which are deflected by galactic and extragalactic magnetic fields, is crucial for tracing the source of these processes.  

The discovery has been made possible by improved techniques for the directional reconstruction of neutrino trajectories, which have made it possible to precisely identify NGC1608 as the source of these neutrinos. 

In the future, it is expected that the extension of the IceCube observatory, known as IceCube-Gen2, together with other neutrino telescopes such as KM3NeT in the Mediterranean Sea, will be able to improve its sensitivity and identify many more sources of astrophysical neutrinos, even at higher energies. These observations will help us to unravel the fundamental processes taking place in the Universe in order to finally understand the physical mechanisms that give rise to very high-energy cosmic rays, one of the main unknowns in astroparticle physics today.