Speaker
Description
In recent years, neutrino astronomy has rapidly developed. In 2013, the IceCube collaboration announced the detection of an astrophysical neutrino flux. The origin of this flux is still largely unknown. The most promising source candidate is the close-by Seyfert galaxy NGC 1068, with evidence of 4.2 sigma and a soft spectral index.
In 2022 and 2023, two 100 TeV neutrinos, respectively IC220424A and IC230416A, were spatially coincident with the Seyfert galaxy NGC 7469 at a distance of 70 Mpc. Here, we report an a-posteriori evaluation for the chance coincidence of these two neutrinos with the source based on a Goodness-of-Fit test. We account for the neutrino angular uncertainties and the source distance and study how likely it is to have a similar doublet in coincidence with an X-ray emitting AGN or a Seyfert galaxy, both from dedicated catalogs.
Our test excludes an accidental spatial coincidence at a 3.2 sigma level, keeping open the possibility that the source emitted either one or both neutrinos. For compatibility with precedent IceCube non-detections, the neutrino emission of the source would need to follow a power law spectrum with hard spectral index or be peaked at high energies.
