TeV Gamma Rays and Neutrinos from Winds Driven by Radiatively Inefficient Accretion Flows of Low-Luminosity Active Galactic Nuclei
Abstract
Recently, the Large High Altitude Air Shower Observatory (LHAASO) reported the first TeV gamma-ray detection from a low-luminosity active galactic nucleus (LLAGN) lacking a strong jet. This source, NGC 4278, is one of the nearest LLAGNs that can be studied in detail as a template for more distant objects. Most previous studies have focused on the month-scale-variable gamma-ray activities, seeking to explain them with weak jets. We focus instead on NGC 4278's quiet-period emission, proposing a different mechanism based on a wind launched from a radiatively inefficient accretion flow (RIAF). In particular, we model particle acceleration at a wind-driven shock and calculate the resulting multimessenger emission. To match the TeV gamma-ray fluxes reported by LHAASO in the quiet period, our model requires a wind power of ≲2×1043 erg s−1 with a spectral index of injected cosmic rays of 2.0. We show that this is achievable through Bondi accretion of the ionized gas observed on the 100-pc scale, for a shallow accretion profile. We discuss the testability of our wind-driven shock scenario with multimessenger observations. As another important application, we extend our model to Sgr A*, the nearest LLAGN, and show that its TeV gamma-ray emission is reproduced with reasonable parameters. Our results suggest that RIAF-driven winds may be a generic emission mechanism in LLAGNs, making this class a potentially important population of both gamma-ray emitters and cosmic-ray accelerators.
Related
- Signatures of Lorentz violation in the bright ring for Sgr A* images from radiatively inefficient accretion flows
- PeV Diffuse Neutrinos from Magnetically Arrested Disks in Low-Luminosity Active Galactic Nuclei
- Correlation of galactic very-high-energy gamma-ray sources detected by LHAASO with high-energy neutrinos
- Differential Luminosity Response of Balmer-Line Profiles in Galactic B/A Luminous Stars
- The Radius-Luminosity Relationship for Active Galactic Nuclei with Hierarchical Bayesian Reverberation Mapping
BibTeX
@misc{sakai2026gamma,
title = {{TeV Gamma Rays and Neutrinos from Winds Driven by Radiatively Inefficient Accretion Flows of Low-Luminosity Active Galactic Nuclei}},
author = {Nobuyuki Sakai and John F. Beacom and Kohta Murase},
howpublished = {arXiv},
year = {2026},
month = aug,
doi = {10.48550/arxiv.2608.30596},
eprint = {2608.30596},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2608.30596},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - TeV Gamma Rays and Neutrinos from Winds Driven by Radiatively Inefficient Accretion Flows of Low-Luminosity Active Galactic Nuclei
AU - Nobuyuki Sakai
AU - John F. Beacom
AU - Kohta Murase
PY - 2026
DA - 2026/08/31
PB - arXiv
DO - 10.48550/arxiv.2608.30596
UR - https://arxiv.org/abs/2608.30596
AB - Recently, the Large High Altitude Air Shower Observatory (LHAASO) reported the first TeV gamma-ray detection from a low-luminosity active galactic nucleus (LLAGN) lacking a strong jet. This source, NGC 4278, is one of the nearest LLAGNs that can be studied in detail as a template for more distant objects. Most previous studies have focused on the month-scale-variable gamma-ray activities, seeking to explain them with weak jets. We focus instead on NGC 4278's quiet-period emission, proposing a different mechanism based on a wind launched from a radiatively inefficient accretion flow (RIAF). In particular, we model particle acceleration at a wind-driven shock and calculate the resulting multimessenger emission. To match the TeV gamma-ray fluxes reported by LHAASO in the quiet period, our model requires a wind power of ≲2×10^43 erg s^−1 with a spectral index of injected cosmic rays of 2.0. We show that this is achievable through Bondi accretion of the ionized gas observed on the 100-pc scale, for a shallow accretion profile. We discuss the testability of our wind-driven shock scenario with multimessenger observations. As another important application, we extend our model to Sgr A*, the nearest LLAGN, and show that its TeV gamma-ray emission is reproduced with reasonable parameters. Our results suggest that RIAF-driven winds may be a generic emission mechanism in LLAGNs, making this class a potentially important population of both gamma-ray emitters and cosmic-ray accelerators.
ER -