A MODEL FOR THE INNER JET HIGH-ENERGY EMISSION OF CENTAURUS A

We investigate the spectral energy distribution (SED) of Centaurus A resulting from a steady compact acceleration region, located close to the central black hole, where both leptonic and hadronic relativistic populations arise. We present here results of such a model, where we have considered synchrotron radiation by primary electrons and protons, inverse Compton scattering, and gamma-ray emission originated by the inelastic hadronic interactions between relativistic protons and cold nuclei within the jets. Photo-meson production by relativistic hadrons were also taken into account, as well as the effects of secondary particles injected by all interactions. The internal and external absorption of gamma-rays is shown to be of great relevance to shape the observable SED, which was also recently constrained by the results of Fermi and HESS.

[1]  et al,et al.  FERMI/LARGE AREA TELESCOPE BRIGHT GAMMA-RAY SOURCE LIST , 2009, 0902.1340.

[2]  Gustavo E. Romero,et al.  The proton low-mass microquasar: high-energy emission , 2008, 0804.4606.

[3]  L. Costamante,et al.  Formation of hard very high energy gamma-ray spectra of blazars due to internal photon-photon absorption , 2008, 0801.3198.

[4]  S. Migliari,et al.  Jet-dominated advective systems: radio and X-ray luminosity dependence on the accretion rate , 2006, astro-ph/0603731.

[5]  G. Dubus Gamma-ray absorption in massive X-ray binaries , 2005, astro-ph/0509633.

[6]  M. Rejkuba The distance to the giant elliptical galaxy NGC 5128 , 2003, astro-ph/0310639.

[7]  F. Aharonian TeV gamma rays from BL Lac Objects due to synchrotron radiation of extremely high energy protons , 2000, astro-ph/0003159.

[8]  M. Kafatos,et al.  Implications of Gamma-Ray Transparency Constraints in Blazars: Minimum Distances and Gamma-Ray Collimation , 1996, astro-ph/9608095.

[9]  D. Meier,et al.  Thick accretion disks - Self-similar, supercritical models , 1982 .

[10]  J. E. Grindlay,et al.  Evidence for the detection of gamma rays from Centaurus A at E gamma ≥ 3×10 11 eV. , 1975 .

[11]  V. Ginzburg On the origin of cosmic rays , 1961, Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences.

[12]  F. Hoyle,et al.  Origin of Cosmic Rays , 1948, Nature.

[13]  O. Williams,et al.  COMPTEL OBSERVATIONS OF CENTAURUS A AT MEV ENERGIES IN THE YEARS 1991 TO 1995 , 1998 .

[14]  A. Atoyan Relativistic neutrons in active galactic nuclei. I : Energy transport from the core , 1992 .