Neutrinos from a blazar jet and the birth of non-stellar neutrino astronomy

IceCube has recently reported the discovery of high-energy neutrinos of astrophysical origin,
opening up the PeV (10^15 eV) sky. These observations are challenging to interpret on the
astronomical side and have triggered a fruitful collaboration across particle and astro-physics.
I will discuss the very recent association between high-energy IceCube neutrinos and the
blazar TXS 0506+056, reporting on how this result fits with the work done by our group over
the past five years. I will then present the “big picture”, explain why this this association is

very important for astronomy, and discuss some very recent results on the nature of TXS 0506+056.

The talk is self-contained, requires no previous knowledge of neutrinos or blazars, and has been

prepared for a very broad audience.