2016/02/24 by D. Horns, Horns, D. · 2 citations
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Astrophysics of Galaxies (astro-ph.GA) #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #Dark Matter and Cosmic Phenomena #FOS: Physical sciences #High Energy Astrophysical Phenomena (astro-ph.HE) #Particle Detector Development and Performance
paper · pdf · doi:10.48550/arxiv.1602.07499
openalex publication_date 2016/02/24 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The propagation of very high energy gamma-rays (E>100~GeV) over cosmological distances is suppressed by pair-production processes with the ubiquitous extra-galactic soft photon background, mainly 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 have been claimed in the past. Here the status of the observations is summarized, an update on the search for the persisting anomalous transparency is given and discussed.