Establishing accretion flares from massive black holes as a source of high-energy neutrinos

Understand

The origin of cosmic high-energy neutrinos remains largely unexplained.

• For high-energy neutrino alerts from IceCube, a coincidence with time-variable emission has been seen for three different types of accreting black holes: (1) a gamma-ray flare from a blazar (TXS 0506+056), (2) an optical transient following a stellar tidal disruption event (TDE; AT2019dsg), and (3) an optical outburst from an active galactic nucleus (AGN; AT2019fdr).
• For the latter two sources, infrared follow-up observations revealed a powerful reverberation signal due to dust heated by the flare.
• This discovery motivates a systematic study of neutrino emission from all supermassive black hole with similar dust echoes.