Search

While observations in the radio band are providing essential information on the innermost structures of relativistic jets in active galactic nuclei (AGN), the recent detection by Fermi of gamma-ray emission from many hundreds of blazars shows that the maximum jet power is emitted at high energies. Multi-wavelength monitoring observations further allow variability studies of the AGN spectral energy distributions over 13 orders of magnitude in frequency. The Joint Discussion offered the possibility for a comprehensive discussion of advances in the observational domain and stimulated theoretical discussion about our current understanding of jet physics., Comment: 11 pages, 5 figures, Highlights of Astronomy, Vol. 16, in press

Estimation of the relative intensities of protons and heavy nuclei in primary cosmic rays in the energy region 10 to the 15th power approx. 10 to the 17th power eV, was done by a systematic comparison between all available observed data on various parameters of extensive air showers (EAS) and the results of simulation. The interaction model used is an extrapolation of scaling violation indicated by recent pp collider results. A composition consisting of various percentages of Fe in an otherwise pure proton beam was assumed. Greatest overall consistency between the data and the simulation is found when the Fe fraction is in the region of 25%.