Please use this identifier to cite or link to this item: http://hdl.handle.net/2440/115005
Scopus Web of Science® Citations ? ?
DC FieldValueLanguage
dc.contributor.authorAab, A.en
dc.contributor.authorAbreu, P.en
dc.contributor.authorAglietta, M.en
dc.contributor.authorAlbuquerque, I.en
dc.contributor.authorAllekotte, I.en
dc.contributor.authorAlmela, A.en
dc.contributor.authorAlvarez Castillo, J.en
dc.contributor.authorAlvarez-Muñiz, J.en
dc.contributor.authorAnastasi, G.en
dc.contributor.authorAnchordoqui, L.en
dc.contributor.authorAndringa, S.en
dc.contributor.authorAramo, C.en
dc.contributor.authorArsene, N.en
dc.contributor.authorAsorey, H.en
dc.contributor.authorAssis, P.en
dc.contributor.authorAvila, G.en
dc.contributor.authorBalaceanu, A.en
dc.contributor.authorBarbato, F.en
dc.contributor.authoret al.en
dc.date.issued2018en
dc.identifier.citationAstrophysical Journal Letters, 2018; 853(2):L29-1-L29-10en
dc.identifier.issn2041-8205en
dc.identifier.issn2041-8213en
dc.identifier.urihttp://hdl.handle.net/2440/115005-
dc.description.abstractA new analysis of the data set from the Pierre Auger Observatory provides evidence for anisotropy in the arrival directions of ultra-high-energy cosmic rays on an intermediate angular scale, which is indicative of excess arrivals from strong, nearby sources. The data consist of 5514 events above $20\,\mathrm{EeV}$ with zenith angles up to 80° recorded before 2017 April 30. Sky models have been created for two distinct populations of extragalactic gamma-ray emitters: active galactic nuclei from the second catalog of hard Fermi-LAT sources (2FHL) and starburst galaxies from a sample that was examined with Fermi-LAT. Flux-limited samples, which include all types of galaxies from the Swift-BAT and 2MASS surveys, have been investigated for comparison. The sky model of cosmic-ray density constructed using each catalog has two free parameters, the fraction of events correlating with astrophysical objects, and an angular scale characterizing the clustering of cosmic rays around extragalactic sources. A maximum-likelihood ratio test is used to evaluate the best values of these parameters and to quantify the strength of each model by contrast with isotropy. It is found that the starburst model fits the data better than the hypothesis of isotropy with a statistical significance of 4.0σ, the highest value of the test statistic being for energies above $39\,\mathrm{EeV}$. The three alternative models are favored against isotropy with 2.7σ–3.2σ significance. The origin of the indicated deviation from isotropy is examined and prospects for more sensitive future studies are discussed.en
dc.description.statementofresponsibilityA. Aab … J. A. Bellido … S. G. Blaess … R. W. Clay … M. J. Cooper … B. R. Dawson … T. D. Grubb … T. A. Harrison … G. C. Hill … P. H. Nguyen … S. J. Saffi … T. Sudholz … P. van Bodegom … et al.en
dc.language.isoenen
dc.publisherIOP Publishingen
dc.subjectAstroparticle physics; cosmic rays; galaxies: active; galaxies: starburst; methods: data analysisen
dc.titleAn indication of anisotropy in arrival directions of ultra-high-energy cosmic rays through comparison to the flux pattern of extragalactic gamma-ray sourcesen
dc.typeJournal articleen
dc.identifier.rmid0030082552en
dc.identifier.doi10.3847/2041-8213/aaa66den
dc.identifier.pubid397601-
pubs.library.collectionPhysics publicationsen
pubs.library.teamDS05en
pubs.verification-statusVerifieden
pubs.publication-statusPublisheden
dc.identifier.orcidBellido, J. [0000-0002-0833-9194]en
dc.identifier.orcidClay, R. [0000-0002-9040-9648]en
dc.identifier.orcidDawson, B. [0000-0002-4271-3055]en
Appears in Collections:IPAS publications
Physics publications

Files in This Item:
There are no files associated with this item.