Hadron acceleration in luminous cosmic high-energy neutrino and gamma-ray sources

• Applicants: Professor Dr. Wolfgang Rhode; Professor Dr. Reinhard Schlickeiser
• Subject Area: Astrophysics and Astronomy
• Term: from 2008 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 66741702

• Final Report Year: 2015

Final Report Abstract

We investigated the electromagnetic acceleration of high-energy hadrons and their subsequent correlated neutrino and photon generation in inelastic hadron-hadron and hadron-photon collisions with ambient target matter and photon radiation fields in extragalactic compact sources especially blazars, a powerful subclass of active galactic nuclei. The energy spectra of relativistic hadrons and electrons resulting from the conversion of relativistic bulk motion by the relativistic pick-up process are calculated. Here, the dominant cooling mechanism already yield an upper limit on the flare duration showing a crucial difference of flares that are generated by electrons and hadrons, respectively. Furthermore, the relativistic electron and hadron distributions are used to calculate high-energy photon and neutrino energy spectra and light curves from accelerated hadrons and electrons in these objects. In doing so, characteristic features of flaring blazars are obtained with respect to causality and retardation effects between the generated photons inside and at the edge of the emission cloud. On the one hand, there are frequency dependent time lags indicating the underlying emission scenario that also enable to determine the time slot of a corresponding neutrino signal at the observer. On the other hand, the consequences on the SEDs due to non-linear SSC cooling indicate that external photon sources are no longer needed to account for a dominating inverse-Compton peak. Finally, the energy spectra and light curves are compared with observations of PKS 2155-305, 3C 279 and 3C 454.3 from TeV-gamma ray telescopes showing a quite good agreement of theory and observation.

Publications

• Blazar synchrotron emission of instantaneously power-law injected electrons under linear synchrotron, non-linear SSC, and combined synchrotron-SSC cooling, Astron. Astrophys. 524 (2010) A31
  Zacharias, M. and Schlickeiser, R.
  
• Retardation of nonthermal photon light curves from flaring blazars I. Synchrotron radiation, Astron. Astrophys. 511 (2010) A26
  Eichmann, E., Schlickeiser, R. and Rhode, W.
  
• Internal γγ-opacity in active galactic nuclei and the consequences for the TeV observations of M 87 and Cen A, Astrophys. J. 736 (2011) 68
  Brodatzki, K. A., Pardy, D. J. S., Becker, J. K. and Schlickeiser, R.
  
• A new ordering parameter of spectral energy distributions from synchrotron-self-Compton emitting blazars, Mon. Not. R. Astr. 420 (2012) 84
  Zacharias, M. and Schlickeiser, R.
  
• Differences of leptonic and hadronic radiation production in flaring blazars, Astrophys. J. 749 (2012) 155
  Eichmann, E., Schlickeiser, R. and Rhode, W.
  
• On the duration of blazar synchrotron flares, Astrophys. J. 744 (2012) 153
  Eichmann, E., Schlickeiser, R. and Rhode, W.