A search for neutrino emission from cores of Active Galactic Nuclei

Abstract

The sources of the majority of the high-energy astrophysical neutrinos observed with the IceCube neutrino telescope at the South Pole are unknown. So far, only a gamma-ray blazar was compellingly associated with the emission of high-energy neutrinos. In addition, several studies suggest that the neutrino emission from the gamma-ray blazar population only accounts for a small fraction of the total astrophysical neutrino flux. In this work we probe the production of high-energy neutrinos in the cores of Active Galactic Nuclei (AGN), induced by accelerated cosmic rays in the accretion disk region. We present a likelihood analysis based on eight years of IceCube data, searching for a cumulative neutrino signal from three AGN samples created for this work. The neutrino emission is assumed to be proportional to the accretion disk luminosity estimated from the soft X-ray flux. Next to the observed soft X-ray flux, the objects for the three samples have been selected based on their radio emission and infrared color properties. For the largest sample in this search, an excess of high-energy neutrino events with respect to an isotropic background of atmospheric and astrophysical neutrinos is found, corresponding to a post-trial significance of 2.60$\sigma$. Assuming a power-law spectrum, the best-fit spectral index is $2.03_{-0.11}^{+0.14}$, consistent with expectations from particle acceleration in astrophysical sources. If interpreted as a genuine signal with the assumptions of a proportionality of X-ray and neutrino fluxes and a model for the sub-threshold flux distribution, this observation implies that at 100 TeV, 27$\%$ - 100$\%$ of the observed neutrinos arise from particle acceleration in the core of AGN.

14 pages, 12 figures, 2 tables

References in corpus (20)

• The eROSITA X-ray telescope on SRG
• The spectrum of isotropic diffuse gamma-ray emission between 100 MeV and 820 GeV
• Active Galactic Nuclei: what's in a name?
• The X-ray-to-Optical Properties of Optically-Selected Active Galaxies Over Wide Luminosity and Redshift Ranges
• IceCube-Gen2: The Window to the Extreme Universe
• Second ROSAT all-sky survey (2RXS) source catalogue
• Time-integrated Neutrino Source Searches with 10 years of IceCube Data
• The IceCube high-energy starting event sample: Description and flux characterization with 7.5 years of data
• Characteristics of the diffuse astrophysical electron and tau neutrino flux with six years of IceCube high energy cascade data
• The contribution of Fermi-2LAC blazars to the diffuse TeV-PeV neutrino flux
• A tidal disruption event coincident with a high-energy neutrino
• Constraining High-Energy Cosmic Neutrino Sources: Implications and Prospects
• On the Origin of High Energy Neutrinos from NGC 1068: The Role of Non-Thermal Coronal Activity
• High-Energy Neutrinos from Magnetized Coronae of Active Galactic Nuclei and Prospects for Identification of Seyfert Galaxies and Quasars in Neutrino Telescopes
• The XMM-Newton Serendipitous Survey. VI. The X-ray Luminosity Function
• High-energy neutrinos from radio galaxies
• Multi-messenger tests of cosmic-ray acceleration in radiatively inefficient accretion flows
• Nonthermal processes in hot accretion flows onto supermassive black holes: An inhomogeneous model
• Gamma-ray and Neutrino Signals from Accretion Disk Coronae of Active Galactic Nuclei
• High-Energy Neutrinos from Blazar Flares and Implications of TXS 0506+056

Cited by in corpus (26)

• Establishing accretion flares from massive black holes as a source of high-energy neutrinos
• Constraining High-Energy Neutrino Emission from Supernovae with IceCube
• Neutrino follow-up with the Zwicky Transient Facility: Results from the first 24 campaigns
• Implications of multiwavelength spectrum on cosmic-ray acceleration in blazar TXS 0506+056
• Probing the connection between IceCube neutrinos and MOJAVE AGN
• High-energy neutrinos from choked-jet supernovae: Searches and implications
• Constraining the contribution of Seyfert galaxies to the diffuse neutrino flux in light of point source observations
• $Fermi$-LAT follow-up observations in seven years of real-time high-energy neutrino alerts
• Ultra-high-energy cosmic rays from ultra-fast outflows of active galactic nuclei
• Scattering of neutrinos by a rotating black hole accounting for the electroweak interaction with an accretion disk
• A stacked search for spatial coincidences between IceCube neutrinos and radio pulsars
• Beyond first light: Global monitoring for high-energy neutrino astronomy
• Neutrino spin oscillations in a magnetized Polish doughnut
• Machine learning applications for the study of AGN physical properties using photometric observations
• Cross-correlating IceCube neutrinos with a large set of galaxy samples around redshift z ~ 1
• Deciphering the Sources of Cosmic Neutrinos
• Strong Lensing of High-Energy Neutrinos
• First Search for High-Energy Neutrino Emission from Galaxy Mergers
• Confronting the dark matter capture rate with a continuous gravitational wave probe of local neutron stars
• Flat Spectrum Radio Quasars as high-energy neutrino sources
• Searches for beyond-standard-model physics with astroparticle physics instruments
• Flavor Matters, but Matter Flavors: Matter Effects on Flavor Composition of Astrophysical Neutrinos
• Neutrinos from extreme astrophysical sources
• KamLAND's search for correlated low-energy electron antineutrinos with astrophysical neutrinos from IceCube
• Hadronic origin of gamma rays and neutrinos from blazars: Multi-messenger implications and observational constraints
• Neutrino Astronomy at High Energies - An Experimental Review