Neutrino and pair creation in reconnection-powered coronae of accreting black holes

Abstract

A ubiquitous feature of accreting black hole systems is their hard X-ray emission which is thought to be produced through Comptonization of soft photons by electrons and positrons in the vicinity of the black hole, in a region with optical depth of order unity. The origin and composition of this Comptonizing region, known as the corona, is a matter open for debate. In this paper we investigate the role of relativistic protons accelerated in black-hole magnetospheric current sheets for the pair enrichment and neutrino emission of AGN coronae. Our model has two free parameters, namely the proton plasma magnetization ${\sigma }_{\mathrm{p}}$, which controls the peak energy of the neutrino spectrum, and the Eddington ratio ${\lambda }_{\mathrm{X},\mathrm{Edd}}$ (defined as the ratio between X-ray luminosity $L_{\mathrm{X}}$ and Eddington luminosity $L_{\mathrm{Edd}}$), which controls the amount of energy transferred to secondary particles. For sources with ${\lambda }_{\mathrm{X},\mathrm{Edd}}\gtrsim {\lambda }_{\mathrm{Edd},\mathrm{crit}}$ (where ${\lambda }_{\mathrm{Edd},\mathrm{crit}}\sim 10^{-1}$ for ${\sigma }_{\mathrm{p}}=10^5$ or $\sim 10^{-2}$ for ${\sigma }_{\mathrm{p}}=10^7$), proton-photon interactions and $\gamma \gamma$ annihilation produce enough secondary pairs to achieve Thomson optical depths ${\tau }_{\mathrm{T}}\sim 0.1-10$. In the opposite case of ${\lambda }_{\mathrm{X},\mathrm{Edd}}\lesssim {\lambda }_{\mathrm{Edd},\mathrm{crit}}$, the coronal pairs cannot originate only from hadronic interactions. Additionally, we find that the neutrino luminosity scales as $L_{\mathrm{X}}^2/L_{\mathrm{Edd}}$ for ${\lambda }_{\mathrm{X},\mathrm{Edd}}\lesssim {\lambda }_{\mathrm{Edd},\mathrm{crit}}$, while it is proportional to $L_{\mathrm{X}}$ for higher ${\lambda }_{\mathrm{X},\mathrm{Edd}}$ values. We apply our model to four Seyfert galaxies, including NGC 1068, and discuss our results in light of recent IceCube observations.

33 pages, Published on JCAP (JCAP04(2025)075)

References in corpus (31)

• BAT AGN Spectroscopic Survey - V. X-ray properties of the Swift/BAT 70-month AGN catalog
• IceCube-Gen2: The Window to the Extreme Universe
• Evidence for neutrino emission from the nearby active galaxy NGC 1068
• Relativistic Jets Shine through Shocks or Magnetic Reconnection?
• BAT AGN Spectroscopic Survey I: Spectral Measurements, Derived Quantities, and AGN Demographics
• Magnetic Reconnection and Hot Spot Formation in Black Hole Accretion Disks
• The Hubble flow around the CenA / M83 galaxy complex
• Photohadronic origin of $\gamma$-ray BL Lac emission: implications for IceCube neutrinos
• BASS XXII: The BASS DR2 AGN Catalog and Data
• Circumnuclear Gas in Seyfert 1 Galaxies: Morphology, Kinematics, and Direct Measurement of Black Hole Masses
• Radiation spectra of warm and optically thick coronae in AGN
• Hidden Hearts of Neutrino Active Galaxies
• Fast particle acceleration in three-dimensional relativistic reconnection
• The Black Hole Mass of NGC 4151. II. Stellar Dynamical Measurement from Near-Infrared Integral Field Spectroscopy
• Point-source and diffuse high-energy neutrino emission from Type IIn supernovae
• The Cepheid Distance to the Seyfert 1 Galaxy NGC 4151
• Implications of a PeV neutrino spectral cutoff in GRB models
• TeV neutrinos and hard X-rays from relativistic reconnection in the corona of NGC 1068
• High-Energy Neutrinos from Active Galactic Nuclei
• Comptonization by Reconnection Plasmoids in Black Hole Coronae I: Magnetically Dominated Pair Plasma
• Disentangling the Hadronic Components in NGC 1068
• Reconnection-driven flares in 3D black hole magnetospheres -- A scenario for hot spots around Sagittarius A*
• Sub-GeV Gamma Rays from Nearby Seyfert Galaxies and Implications for Coronal Neutrino Emission
• A magnetized strongly turbulent corona as the source of neutrinos from NGC 1068
• Comptonization by Reconnection Plasmoids in Black Hole Coronae II: Electron-Ion Plasma
• Reaching the Peak of the quasar spectral energy distribution - II. Exploring the accretion disc, dusty torus and host galaxy
• The neutrino background from non-jetted active galactic nuclei
• A marginally fast-cooling proton-synchrotron model for prompt GRBs
• Hadronic X-ray Flares from Blazars
• Concurrent Particle Acceleration and Pitch-Angle Anisotropy Driven by Magnetic Reconnection: Ion-Electron Plasmas
• A closer look at the electromagnetic signatures of Bethe-Heitler pair production process in blazars

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• Neutrinos from extreme astrophysical sources