Gamma-ray emission from the Seyfert galaxy NGC 4151: multi-messenger implications for ultra-fast outflows
Year: 2025
Type: article
Abstract: The nuclear activity typical of Seyfert galaxies can drive powerful winds where high-energy phenomena occur. In spite of their high power content, the number of such non-jetted active galactic nuclei (AGN) detected in gamma rays is very limited. 4FGL J1210.3+ 3928, a source recently discovered by the Fermi-LAT telescope, is spatially consistent with the blazar 1E 1217.9+3945 and NGC 4151, a Seyfert galaxy located at about 15.8 Mpc known for hosting ultra-fast outflows (UFOs) in its innermost core. We show that the localization of 4FGL J1210.3+3928 might be affected by fluctuations due to a superposition of the two nearby sources. We explore the possibility of NGC 4151 to be a high-energy source and we conclude that particle acceleration at the UFO wind termination shock can explain the luminosity and spectral shape of the observed gamma-ray flux, whereas the multiwavelength spectral energy distribution of 1E 1217.9+3945 disfavors it as the dominant GeV gamma-ray counterpart. Interestingly, NGC 4151 is also spatially coincident with a weak excess of neutrino events identified by the IceCube neutrino observatory. We compute the contribution of the UFO to such a neutrino excess and we discuss other possible emission regions such as the AGN nearest neighborhood.
Institutions: University of Copenhagen, Centre National de la Recherche Scientifique, Université Paris Cité, Arcetri Astrophysical Observatory, National Institute for Astrophysics, University of Rome Tor Vergata, Goddard Space Flight Center, Astronomical Observatory of Rome, Istituto Nazionale di Fisica Nucleare, Roma Tor Vergata, University of Maryland, College Park, Agenzia Spaziale Italiana
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,290
OpenAlex ID: W4412018536