Albert, J.Aliu, E.Antoranz, P.Baixeras Divar, CarmenBarrio, J. A.Bordas Coma, PolBosch i Ramon, ValentíCamara, M.Contreras, J. L.Cortina Blanco, JuanCea del Pozo, Elsa deReyes, R. de losErrando, M.Fernández Sánchez, EnriqueFirpo, R.Paredes i Poy, Josep MariaRibó Gomis, MarcSierpowska-Bartosik, A.Tescaro, DiegoZabalza de Torres, Víctor2013-07-192013-07-1920080036-8075https://hdl.handle.net/2445/44986The 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.9 p.application/pdfeng(c) Albert, J. et al., 2008QuàsarsTelescopis espacialsAstronomia de raigs gammaAstrofísicaQuasarsSpace telescopesGamma ray astronomyAstrophysicsinfo:eu-repo/semantics/article5673632013-07-19info:eu-repo/semantics/openAccess18583607