# Search for high-energy neutrinos from AGN cores

## TL;DR

This study investigates whether the cores of Active Galactic Nuclei (AGN) are significant sources of high-energy neutrinos by analyzing a decade of IceCube data and correlating neutrino events with various AGN sub-populations.

## Contribution

It performs a stacking analysis of multiple AGN sub-populations based on multi-wavelength data to test their correlation with high-energy neutrinos, exploring a potential new neutrino source class.

## Key findings

- No significant correlation found between AGN cores and neutrino flux.
- Supports the idea that AGN cores may contribute to the diffuse neutrino background.
- Provides constraints on neutrino emission models from AGN cores.

## Abstract

IceCube is a cubic-kilometer Cherenkov telescope operating at the South Pole. In 2013 IceCube discovered high-energy astrophysical neutrinos and has more recently found compelling evidence for a flaring blazar being a source of high-energy neutrinos. However, as blazars can only be responsible for a small fraction of the observed neutrino flux, the sources responsible for the majority of the detected neutrinos remain unknown. In this work, we explore the possibility that the observed neutrino flux is produced in the cores of Active Galactic Nuclei (AGN). Various models have predicted neutrino emission from the accretion disks of AGN. According to these models, the neutrino luminosity would not depend strongly on either the orientation or other parameters of the relativistic jet. Both jetted and non-jetted AGN could contribute to the neutrino flux. We perform a stacking analysis to test for correlation between various sub-populations of AGN and high-energy neutrinos using a decade of IceCube data. We select AGN based on their radio emission, infrared color properties, and X-ray flux using the NVSS, AllWISE, ROSAT and XMMSL2 catalogs. We use the accretion disk luminosity, estimated from the observed soft X-ray flux, to weight the contribution of selected galaxies to the neutrino signal.