Multi-messenger astronomy with Centaurus A

Abstract

We calculated for the nearest active galactic nucleus (AGN), Centaurus A (Cen A), the flux of high energy cosmic rays and of accompanying secondary photons and neutrinos expected from hadronic interactions in the source. We used as two basic models for the generation of ultrahigh energy cosmic rays (UHECR) shock acceleration in the radio jet and acceleration in the regular electromagnetic field close to the core of the AGN, normalizing the UHECR flux to the observations of the Auger experiment. Here we compare the previously obtained photon fluxes with the recent data reported by the Fermi LAT and H.E.S.S. collaborations. In the case of the core model, we find good agreement both for the predicted spectral shape and the overall normalization between our earlier results and the H.E.S.S. observations for a primary proton energy $dN/dE\propto E^{-\alpha }$ with $\alpha \sim 2$ or smaller. A broken-power law with high-energy part $\alpha =-2.7$ leads to photon fluxes in excess of the Fermi measurements. The energy spectrum of the photon fluxes obtained by us for the jet scenario is in all cases at variance with the H.E.S.S. and Fermi observations.

5 pages, 6 figures. Contribution to the proceedings of the 2nd Heidelberg Workshop "High-Energy Gamma-rays and Neutrinos from Extra-Galactic Sources"

References in corpus (5)

• Centaurus A - NGC 5128
• Search for Correlations between HiRes Stereo Events and Active Galactic Nuclei
• High energy neutrino yields from astrophysical sources I: Weakly magnetized sources
• High energy neutrino yields from astrophysical sources II: Magnetized sources
• Anisotropies and clustering of extragalactic cosmic rays

Cited by in corpus (7)

• Hadronic-Origin TeV gamma-Rays and Ultra-High Energy Cosmic Rays from Centaurus A
• LUNASKA Experiment Observational Limits on UHE Neutrinos from Centaurus A and the Galactic Center
• TeV gamma-rays from UHECR interactions in AGN cores: Lessons from Centaurus A
• An upper limit on the cosmic-ray luminosity of individual sources from gamma-ray observations
• A limit on the ultra-high-energy neutrino flux from lunar observations with the Parkes radio telescope
• IceCube expectations for two high-energy neutrino production models at active galactic nuclei
• Status and Strategies of Current LUNASKA Lunar Cherenkov Observations with the Parkes Radio Telescope