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Participant |
Horns, Dieter | |||||||
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Institution |
University of Hamburg - Luruper Chaussee 149 - Hamburg - Hamburg - Germany | |||||||
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Session |
HE1 |
Accepted |
Yes |
Order |
2 |
Time |
15:00 | 30' |
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Talk |
Oral abstract |
Title |
The Transparency of the Universe for Very High Energy Gamma-rays | |||||
| Coauthors | ||||||||
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Abstract |
The propagation of very high energy gamma-rays (E>100 GeV) over cosmological distances is limited by pair-production processes with the ubiquitous extra-galactic soft photon background in the optical to near infra-red. The detailed spectroscopy of gamma-ray emitting Blazars has revealed the signature of this absorption process leading to a meaningful measurement of the background photon field which is linked to the star-forming history of the universe. Deviations from the expected absorption could be linked to the presence of light fundamental bosons in the mass range of nano to micro eV. Here the status of the observations is summarized and discussed in the context of sensitivity of ongoing and future observational searches. |
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