AGN outflows as neutrino sources: an observational test

TL;DR

This study investigates whether AGN outflows are sources of neutrinos by cross-correlating AGN data with IceCube neutrino observations and analyzing spectral line profiles, finding no significant association but suggesting possible contributions at high velocities and luminosities.

Contribution

The paper provides the first comprehensive observational test of AGN outflows as neutrino sources using cross-correlation and statistical analysis, setting constraints on their role in neutrino production.

Findings

AGN with neutrino-matched outflows have higher energy and bolometric powers.

No statistically significant correlation between AGN outflows and IceCube neutrinos.

High-velocity and luminous outflows show the smallest p-values, hinting at potential contributions.

Abstract

We test the recently proposed idea that outflows associated with Active Galactic Nuclei (AGN) could be neutrino emitters in two complementary ways. First, we cross-correlate a list of 94 "bona fide" AGN outflows with the most complete and updated repository of IceCube neutrinos currently publicly available, assembled by us for this purpose. It turns out that AGN with outflows matched to an IceCube neutrino have outflow and kinetic energy rates, and bolometric powers larger than those of AGN with outflows not matched to neutrinos. Second, we carry out a statistical analysis on a catalogue of O III 5007 line profiles using a sample of 23,264 AGN at z < 0.4, a sub-sample of which includes mostly possible outflows sources. We find no significant evidence of an association between the AGN and the IceCube events, although we get the smallest p-values (~ 6 and 18 per cent respectively, pre-trial) for relatively high velocities and luminosities. Our results are consistent with a scenario where AGN outflows are neutrino emitters but at present do not provide a significant signal. This can be tested with better statistics and source stacking. A predominant role of AGN outflows in explaining the IceCube data appears in any case to be ruled out.