Gamma-ray fluxes from the core emission of Centaurus A: A puzzle solved

Abstract

A high-energy component in the radio galaxy Centaurus A was reported after analyzing four years of Fermi data. The spectrum of this component is described by means of a broken power law with a break energy of 4 GeV and, below and above spectral indices of ${\alpha }_1$=2.74$\pm$0.03 and ${\alpha }_2$=2.09$\pm$0.20, respectively. Also a faint $\gamma$-ray flux at TeV energies was detected by H.E.S.S.. In this paper we show that the spectrum at GeV-TeV energies is described through synchrotron self-Compton emission up to a few GeV ($\sim$ 4 GeV) and ${\pi }^0$ decay products up to TeV energies, although the emission of synchrotron radiation by muons could contribute to the spectrum at GeV energies, if they are rapidly accelerated. Muons and ${\pi }^0$s are generated in the interactions of accelerated protons with two populations of seed photons which were reported by Compton Gamma-Ray Observatory: one population at intermediate state emission with energy peak of 0.15 MeV and another at low state emission with energy peak of 0.59 MeV. In addition, we show that the reported observations of ultra-high-energy cosmic rays and non high-energy neutrino detection around Centaurus A can be explained through these interactions, assuming that proton spectrum is extended up to ultra-high-energies.

MNRAS, accepted

References in corpus (8)

• High-energy neutrinos in the context of multimessenger physics
• High-energy Particle Acceleration and Production of Ultra-high-energy Cosmic Rays in the Giant Lobes of Centaurus A
• Ultra High Energy Cosmic Rays from Black Hole Jets of Radio Galaxies
• New results on particle acceleration in the Centaurus A jet and counterjet from a deep Chandra observation
• Observations of Selected AGN with H.E.S.S
• Ultra-high energy Neutrinos from Centaurus A and the Auger hot spot
• The infrared jet in Centaurus A: multiwavelength constraints on emission mechanisms and particle acceleration
• Cosmic Neutrinos from the Sources of Galactic and Extragalactic Cosmic Rays

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