Pair production from cosmic ray - photon interactions in radio galaxies
(Supervision: Anita Reimer)
Description
Cosmic rays are (mostly) charged particles bombarding Earth from space which can reach energies of more than 100 EeV. Recent data from the Pierre Auger Observatory reveal a gradual change of the cosmic ray mass composition from proton-dominated to nuclei-dominated starting around EeV energies. Many of the proposed counterpart sources of these energetic cosmic rays possess prominent radiation fields. Hence, cosmic rays may interact with photons in these sources, to produce electron-positron pairs by Bethe-Heitler pair production, which in turn can initiate pair cascades in this environment.
The bachelor project consists of understanding the production of pairs through the interaction of heavy cosmic rays with photons in general and applied to radio galaxies. In particular, the goodness of the approximations for Bethe-Heitler pair production published in Chodorowski et al (1992) shall be evaluated by comparing with the results of corresponding Monte-Carlo simulations using a photopair production event generator.
Literature: Chodorowski, Zdziarski, Sikora, The Astrophysical Journal, Vol 400, p 181ff (1992)