Messengers of the Universe

The past two years have seen momentous changes and new results in Astroparticle Physics: AMS and Pamela have provided measurements of unprecedented statistical precision of the spectra of various types of cosmic rays with unprecedented statistics and precision. Some of theses spectra show rather intriguing features which are topics of ongoing debate. For the first time, neutrinos with energies up to 1015eV have been detected, which must be of extra-terrestrial origin. The number of γ-ray sources has surpassed 150, with Eγ>100GeV, and 3000, with Eγ>100MeV. They belong to a variety of source classes, with many of the sources still being unidentified. With such numbers population studies become feasible, and the the understanding of acceleration mechanisms can be steadily increased. In interactions of relativistic, charged particles γ-rays and neutrinos are produced as secondaries, with somewhat lower energies. Therefore, high-energy cosmic rays, photons and neutrinos, originate likely from the same sources. Thus, the era of multi-messenger observations and analyses has truly arrived. New results pose constraints to a number of models and stimulate the whole field. This is a summary of the parallel presentations from Session IV: “Messengers of the Universe” of the Neutrino Oscillation Workshop 2014.