10.3204/DESY-PROC-2011-04/MEYER_MANUEL
Meyer, Manuel
Manuel
Meyer
Horns, Dieter
Dieter
Horns
Indications for a suppression of pair production at very high energies.
Deutsches Elektronen-Synchrotron, DESY, Hamburg
2011
ConferencePaper
Physics
2011
en
PDF
Proc. of Patras Workshop on Axions, WIMPs and WISPs, 151-157; DESY
The transparency of the universe for very high energy (VHE) photons is limited
due to pair-production with low energy photons of the extra galactic
background light (EBL) in the ultra-violet to infrared wavelength band. Here, we use
58 energy spectra from VHE emitting active galactic nuclei (AGN) from redshift 0.004
to 0.536 to search for signatures of deviations from the minimum expected opacity.
A statistical study of the individual measurements reveals indications for an
overcorrection of AGN spectra with current EBL models.
Axion like particles are discussed as a possible explanation of the result.
Proc. of Patras Workshop on Axions, WIMPs and WISPs, 151 - 157; DESY-PROC-2011-04; ISSN 1435-8077