An upper limit to the photon fraction in cosmic rays above 1019 eV from the Pierre Auger Observatory

Abraham, J.; Aglietta, M.; Aguirre, C.; Allard, D.; Pepe, Iuri Muniz

dc.contributor.author	Abraham, J.
dc.contributor.author	Aglietta, M.
dc.contributor.author	Aguirre, C.
dc.contributor.author	Allard, D.
dc.contributor.author	Pepe, Iuri Muniz
dc.creator	Abraham, J.
dc.creator	Aglietta, M.
dc.creator	Aguirre, C.
dc.creator	Allard, D.
dc.creator	Pepe, Iuri Muniz
dc.date.accessioned	2014-09-09T15:04:50Z
dc.date.issued	2007
dc.identifier.issn	0927-6505
dc.identifier.uri	http://repositorio.ufba.br/ri/handle/ri/15910
dc.description	p. 155–168	pt_BR
dc.description.abstract	An upper limit of 16% (at 95% c.l.) is derived for the photon fraction in cosmic rays with energies greater than 1019 eV, based on observations of the depth of shower maximum performed with the hybrid detector of the Pierre Auger Observatory. This is the first such limit on photons obtained by observing the fluorescence light profile of air showers. This upper limit confirms and improves on previous results from the Haverah Park and AGASA surface arrays. Additional data recorded with the Auger surface detectors for a subset of the event sample support the conclusion that a photon origin of the observed events is not favored.	pt_BR
dc.language.iso	en	pt_BR
dc.rights	Acesso Aberto	pt_BR
dc.source	http://dx.doi.org/10.1016/j.astropartphys.2006.10.004	pt_BR
dc.subject	Cosmic rays	pt_BR
dc.subject	Ultra-high energy photons	pt_BR
dc.subject	Extensive air showers	pt_BR
dc.subject	Pierre Auger Observatory	pt_BR
dc.title	An upper limit to the photon fraction in cosmic rays above 1019 eV from the Pierre Auger Observatory	pt_BR
dc.title.alternative	Astroparticle Physics	pt_BR
dc.type	Artigo de Periódico	pt_BR
dc.identifier.number	v. 27, n. 2-3	pt_BR
dc.embargo.liftdate	10000-01-01