Article

Very-High-Energy Gamma Rays from a Distant Quasar: How Transparent Is the Universe?

Universität Würzburg, D-97074 Würzburg, Germany.
Science (Impact Factor: 31.48). 07/2008; 320(5884):1752-4. DOI: 10.1126/science.1157087
Source: PubMed

ABSTRACT The atmospheric Cherenkov gamma-ray telescope MAGIC, designed for a low-energy threshold, has detected very-high-energy gamma
rays from a giant flare of the distant Quasi-Stellar Radio Source (in short: radio quasar) 3C 279, at a distance of more than
5 billion light-years (a redshift of 0.536). No quasar has been observed previously in very-high-energy gamma radiation, and
this is also the most distant object detected emitting gamma rays above 50 gigaelectron volts. Because high-energy gamma rays
may be stopped by interacting with the diffuse background light in the universe, the observations by MAGIC imply a low amount
for such light, consistent with that known from galaxy counts.

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