EPJ Web of Conferences
Volume 53, 2013UHECR 2012 - International Symposium on Future Directions in UHECR Physics
|Number of page(s)||7|
|Section||Cosmic Ray Sources and Propagation|
|Published online||25 June 2013|
Extragalactic and galactic sources: New evidence, new challenges, new opportunities
1 Department of Physics and Astronomy, University of California, Los Angeles, CA 90095-1547, USA
2 Kavli IPMU, University of Tokyo, Kashiwa, Chiba 277-8568, Japan
a e-mail: email@example.com
Recent data bring in sharper focus the issue of relative contributions of galactic and extragalactic sources of ultrahigh-energy cosmic rays. On the one hand, there is some new evidence, from gamma-ray observations of blazars, that cosmic rays are, indeed, accelerated in AGNs. On the other hand, recent measurements of composition reported by Pierre Auger Observatory can be explained by a contribution of transient galactic sources, such as past GRBs and hypernovae, if nuclei accelerated in such events get trapped in the turbulent galactic magnetic fields. The likely contamination of UHECR data by the nuclei from past galactic stellar explosions creates new challenges for cosmic-ray astronomy. At the same time, it creates new opportunities for reconstructing galactic magnetic fields, understanding the history of transient galactic phenomena, and for using gamma rays to identify astrophysical nuclear accelerators outside Milky Way.
© Owned by the authors, published by EDP Sciences, 2013
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 2.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.