Constraining extragalactic background light from TeV blazars
National Astronomical Observatories, Yunnan Observatory, Chinese Academy of
2 Key Laboratory for the Structure and Evolution of Celestial Objects, Chinese Academy of Sciences, Kunming 650011, PR China
3 Yunnan Agricultural University, Kunming 650201, PR China
Accepted: 17 June 2010
Aims. Our goal is to research the upper limits to the extragalactic background light (EBL).
Methods. The upper limits to the extragalactic background light (EBL) are presented, using the Fermi and very high energy (VHE) spectra recently observed in TeV blazars. We use an assumption that the VHE intrinsic photon index cannot be harder than the Fermi index measured by the Fermi-LAT.
Results. These upper limits are compatible with ones given by most EBL models; however, the models of high EBL density are contradicted by TeV blazars.
Key words: gamma rays: galaxies / BL Lacertae objects: general / diffuse radiation
© ESO, 2010