Nearby Universe's 'Cosmic Fog' Measured

HESS collaboration has carried out the first measurement of the intensity of the diffuse extragalactic background light in the nearby Universe, a fog of photons that has filled the Universe ever since its formation. Using some of the brightest gamma-ray sources in the southern hemisphere, the study was carried out using measurements performed by the HESS telescope array, located in Namibia and involving CNRS and CEA. The study is complementary to that recently carried out by the Fermi-LAT space observatory. These findings provide new insight into the size of the Universe observable in gamma rays and shed light on the formation of stars and the evolution of galaxies.
Science Daily, Jan 19, 2013

A. Abramowski et al.

Measurement of the extragalactic background light imprint on the spectra of the brightest blazars observed with H.E.S.S..

Astronomy & Astrophysics, 2013; 550: A4 DOI: 10.1051/0004-6361/201220355