Summary of Extragalactic News and Progress

摘要

Approximately 90 contributions to the 5th Heidelberg Symposium on High-Energy Gamma-Ray Astronomy (Gamma 2012), presented new results and ideas in the general field of extragalactic high-energy gamma-ray astronomy. The largest contingent of contributions in this field related to active galactic nuclei (AGN), including blazars, radio galaxies, and Narrow-Line Seyfert 1 (NLSyl) galaxies. Also, new results concerning starburst galaxies, as well as (so far) unsuccessful searches for γ-ray emission from other types of extragalactic sources have been reported. Finally, controversial discussions about studies of the γγ absorption imprint of the extragalactic background light on γ-ray emission from blazars, and potential implications for the intergalactic magnetic field have been discussed. This paper will provide a brief summary of the results and ideas on these topics, presented and discussed at Gamma 2012.