Laurentiu I. Caramete, Oana Tascau, Peter L. Biermann, Todor Stanev
Context: As more and more data are collected by cosmic ray experiments such
as the Pierre Auger Observatory and Telescope Array (TA), the search for the
sources of the Ultra High Energy Cosmic Rays (UHECR) continues. Already we have
some hints about the sources or type of sources involved and more work is
required to confirm any of this. Aims: We intend to predict the UHECR fluxes
and the maximal energies of particles from two complete samples of nearby
active galaxies, selected at radio and far-infrared frequencies. Also, we
investigate the magnetic scattering of the UHECR path in the intervening cosmic
space. Methods: We propose here a new method of searching for the sources of
the UHECR in three steps, first we model the activity of the type of sources
and get the flux of UHECR and a maximal energy for particle acceleration, then
we model the interaction and angle deflection in the intergalactic space and
finally we simulate the distribution of the cosmic rays events that can be
statistically compared with future data of the cosmic rays observatories.
Results: We analyzed two classes of sources, gamma ray bursts (GRBs) and Radio
Galaxies (RGs). Ordering by the UHECR flux, few RGs are viable candidates, as
for GRB many sources are viable candidates, requiring less scattering of the
particles along their path to Earth to interpret the presently observed sky
distribution. Most of the flux from RGs comes from the Southern sky, and most
of the flux of particles from GRB comes from the North, although the
differences are so small as to require large statistics to confirm this. The
intergalactic and Galactic magnetic fields may help to distinguish the two
extreme cases, also pure protons from heavy nuclei at the same energy. As a
consequence flat spectrum radio sources such as 3C279 should confirm the
production of UHECR in this class of sources through energetic neutrinos.
View original:
http://arxiv.org/abs/1106.5109
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