Abstract
Active galactic nuclei (AGN) are promising candidate sources of high-energy astrophysical neutrinos, since they provide environments rich in matter and photon targets where cosmic-ray interactions may lead to the production of gamma rays and neutrinos. We searched for high-energy neutrino emission from AGN using the Swift-BAT Spectroscopic Survey catalog of hard X-ray sources and 12 yr of IceCube muon track data. First, upon performing a stacked search, no significant emission was found. Second, we searched for neutrinos from a list of 43 candidate sources and found an excess from the direction of two sources, the Seyfert galaxies NGC 1068 and NGC 4151. We observed NGC 1068 at flux ϕνμ+ν¯μ = 4.02−1.52+1.58 × 10^{−11} TeV^{-1} cm^{-2} s^{-1} normalized at 1 TeV, with a power-law spectral index γ = 3.10−0.22+0.26, consistent with previous IceCube results. The observation of a neutrino excess from the direction of NGC 4151 is at a posttrial significance of 2.9σ. If interpreted as an astrophysical signal, the excess observed from NGC 4151 corresponds to a flux ϕνμ+ν¯μ = 1.51−0.81+0.99 × 10^{−11} TeV^{-1} cm^{-2} s^{-1} normalized at 1 TeV and γ = 2.83−0.28+0.35.
| Original language | English |
|---|---|
| Article number | 131 |
| Number of pages | 17 |
| Journal | The Astrophysical Journal |
| Volume | 981 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - 4 Mar 2025 |
Bibliographical note
Funding Information:The authors gratefully acknowledge the support from the following agencies and institutions: USA\u2014U.S. National Science Foundation\u2014Office of Polar Programs, U.S. National Science Foundation\u2014Physics Division, U.S. National Science Foundation-EPSCoR, U.S. National Science Foundation\u2014Office of Advanced Cyberinfrastructure, Wisconsin Alumni Research Foundation, Center for High Throughput Computing (CHTC) at the University of Wisconsin\u2013Madison, Open Science Grid (OSG), Partnership to Advance Throughput Computing (PATh), Advanced Cyberinfrastructure Coordination Ecosystem: Services & Support (ACCESS), Frontera computing project at the Texas Advanced Computing Center, U.S. Department of Energy\u2014National Energy Research Scientific Computing Center, Particle Astrophysics Research Computing Center at the University of Maryland, Institute for Cyber-Enabled Research at Michigan State University, Astroparticle Physics Computational Facility at Marquette University, NVIDIA Corporation, and Google Cloud Platform; Belgium\u2014Funds for Scientific Research (FRS-FNRS and FWO), FWO Odysseus and Big Science programmes, and Belgian Federal Science Policy Office (Belspo); Germany\u2014Bundesministerium f\u00FCr Bildung und Forschung (BMBF), Deutsche Forschungsgemeinschaft (DFG), Helmholtz Alliance for Astroparticle Physics (HAP), Initiative and Networking Fund of the Helmholtz Association, Deutsches Elektronen Synchrotron (DESY), and High Performance Computing cluster of the RWTH Aachen; Sweden\u2014Swedish Research Council, Swedish Polar Research Secretariat, Swedish National Infrastructure for Computing (SNIC), and Knut and Alice Wallenberg Foundation; European Union\u2014EGI Advanced Computing for Research; Australia\u2014Australian Research Council; Canada\u2014Natural Sciences and Engineering Research Council of Canada, Calcul Qu\u00E9bec, Compute Ontario, Canada Foundation for Innovation, WestGrid, and Digital Research Alliance of Canada; Denmark\u2014Villum Fonden, Carlsberg Foundation, and European Commission; New Zealand\u2014Marsden Fund; Japan\u2014Japan Society for Promotion of Science (JSPS) and Institute for Global Prominent Research (IGPR) of Chiba University; Korea\u2014National Research Foundation of Korea (NRF); Switzerland\u2014Swiss National Science Foundation (SNSF).
Publisher Copyright:
© 2025. The Author(s).
Keywords
- Neutrino astronomy
- High energy astrophysics
- Active galaxies
- Seyfert galaxies