An Indication of Anisotropy in Arrival Directions of Ultra-high-energy Cosmic Rays through Comparison to the Flux Pattern of Extragalactic Gamma-Ray Sources

6533b85dfe1ef96bd12bdd9a

RESEARCH PRODUCT

An Indication of Anisotropy in Arrival Directions of Ultra-high-energy Cosmic Rays through Comparison to the Flux Pattern of Extragalactic Gamma-Ray Sources

A. Aab P. Abreu Marco Aglietta I. F. M. Albuquerque I. Allekotte A. Almela J. Alvarez Castillo J. Alvarez-muñiz G. A. Anastasi L. Anchordoqui B. Andrada S. Andringa C. Aramo N. Arsene H. Asorey P. Assis G. Avila A. M. Badescu A. Balaceanu F. Barbato R. J. Barreira Luz J. J. Beatty K. H. Becker J. A. Bellido C. Berat M. E. Bertaina X. Bertou P. L. Biermann J. Biteau S. G. Blaess A. Blanco J. Blazek C. Bleve M. Boháčová C. Bonifazi N. Borodai A. M. Botti J. Brack I. Brancus T. Bretz A. Bridgeman F. L. Briechle P. Buchholz A. Bueno S. Buitink M. Buscemi K. S. Caballero-mora L. Caccianiga A. Cancio F. Canfora R. Caruso Antonella Castellina F. Catalani G. Cataldi L. Cazon A. G. Chavez J. A. Chinellato J. Chudoba R. W. Clay A. C. Cobos Cerutti R. Colalillo A. Coleman L. Collica M. R. Coluccia R. Conceição G. Consolati F. Contreras M. J. Cooper S. Coutu C. E. Covault J. Cronin S. D'amico B. Daniel S. Dasso K. Daumiller B. R. Dawson R. M. De Almeida S. J. De Jong G. De Mauro J. R. T. De Mello Neto I. De Mitri J. De Oliveira V. De Souza J. Debatin O. Deligny M. L. Díaz Castro F. Diogo C. Dobrigkeit J. C. D'olivo Q. Dorosti R. C. Dos Anjos M. T. Dova A. Dundovic J. Ebr R. Engel M. Erdmann M. Erfani C. O. Escobar J. Espadanal A. Etchegoyen H. Falcke J. Farmer G. Farrar A. C. Fauth N. Fazzini F. Fenu B. Fick J. M. Figueira A. Filipčič M. M. Freire T. Fujii A. Fuster R. Gaïor B. García F. Gaté H. Gemmeke A. Gherghel-lascu P. L. Ghia U. Giaccari M. Giammarchi M. Giller D. Głas C. Glaser G. Golup M. Gómez Berisso P. F. Gómez Vitale N. González Alessio Gorgi A. F. Grillo T. D. Grubb F. Guarino G. P. Guedes R. Halliday M. R. Hampel P. Hansen D. Harari T. A. Harrison A. Haungs T. Hebbeker D. Heck P. Heimann A. E. Herve G. C. Hill C. Hojvat E. Holt P. Homola J. R. Hörandel P. Horvath M. Hrabovský T. Huege J. Hulsman A. Insolia P. G. Isar I. Jandt J. A. Johnsen M. Josebachuili J. Jurysek A. Kääpä O. Kambeitz K. H. Kampert B. Keilhauer N. Kemmerich E. Kemp J. Kemp R. M. Kieckhafer H. O. Klages M. Kleifges J. Kleinfeller R. Krause N. Krohm D. Kuempel G. Kukec Mezek N. Kunka A. Kuotb Awad B. L. Lago D. Lahurd R. G. Lang M. Lauscher R. Legumina M. A. Leigui De Oliveira A. Letessier-selvon I. Lhenry-yvon K. Link D. Lo Presti L. Lopes R. López A. López Casado R. Lorek Q. Luce A. Lucero M. Malacari M. Mallamaci D. Mandat P. Mantsch A. G. Mariazzi I. C. Mariș G. Marsella D. Martello H. Martinez O. Martínez Bravo J. J. Masías Meza H. J. Mathes S. Mathys J. Matthews G. Matthiae E. Mayotte P. O. Mazur C. Medina G. Medina-tanco D. Melo A. Menshikov K. -D. Merenda S. Michal M. I. Micheletti L. Middendorf L. Miramonti B. Mitrica D. Mockler S. Mollerach F. Montanet C. Morello Giovanni Morlino M. Mostafá A. L. Müller G. Müller M. A. Muller S. Müller R. Mussa I. Naranjo L. Nellen P. H. Nguyen M. Niculescu-oglinzanu M. Niechciol L. Niemietz T. Niggemann D. Nitz D. Nosek V. Novotny L. Nožka L. A. Núñez F. Oikonomou A. Olinto M. Palatka J. Pallotta P. Papenbreer G. Parente A. Parra T. Paul M. Pech F. Pedreira J. Pȩkala R. Pelayo J. Peña-rodriguez L. A. S. Pereira M. Perlin L. Perrone C. Peters S. Petrera J. Phuntsok T. Pierog M. Pimenta V. Pirronello M. Platino M. Plum J. Poh C. Porowski R. R. Prado P. Privitera M. Prouza E. J. Quel S. Querchfeld S. Quinn R. Ramos-pollan J. Rautenberg D. Ravignani J. Ridky F. Riehn M. Risse P. Ristori V. Rizi W. Rodrigues De Carvalho G. Rodriguez Fernandez J. Rodriguez Rojo M. J. Roncoroni M. Roth E. Roulet A. C. Rovero P. Ruehl S. J. Saffi A. Saftoiu F. Salamida H. Salazar A. Saleh G. Salina F. Sánchez P. Sanchez-lucas E. M. Santos E. Santos F. Sarazin R. Sarmento C. Sarmiento-cano R. Sato M. Schauer V. Scherini H. Schieler M. Schimp D. Schmidt O. Scholten P. Schovánek F. G. Schröder S. Schröder A. Schulz J. Schumacher S. J. Sciutto Alberto Segreto A. Shadkam R. C. Shellard G. Sigl G. Silli R. ŠMída G. R. Snow P. Sommers S. Sonntag J. F. Soriano R. Squartini D. Stanca S. Stanič J. Stasielak P. Stassi M. Stolpovskiy F. Strafella A. Streich F. Suarez M. Suarez Durán T. Sudholz T. Suomijärvi A. D. Supanitsky J. ŠUpík J. Swain Z. Szadkowski A. Taboada O. A. Taborda V. M. Theodoro C. Timmermans C. J. Todero Peixoto L. Tomankova B. Tomé G. Torralba Elipe P. Travnicek M. Trini R. Ulrich M. Unger M. Urban J. F. Valdés Galicia I. Valiño L. Valore G. Van Aar P. Van Bodegom A. M. Van Den Berg A. Van Vliet E. Varela B. Vargas Cárdenas R. A. Vázquez D. Veberič C. Ventura I. D. Vergara Quispe V. Verzi J. Vicha L. Villaseñor S. Vorobiov H. Wahlberg O. Wainberg D. Walz A. A. Watson M. Weber A. Weindl M. Wiedeński L. Wiencke H. Wilczyński M. Wirtz D. Wittkowski B. Wundheiler L. Yang A. Yushkov E. Zas D. Zavrtanik M. Zavrtanik A. Zepeda B. Zimmermann M. Ziolkowski Z. Zong Francesca Zuccarello Pierre Auger Collaboration

subject

Astronomy [ PHYS.ASTR ] Physics [physics]/Astrophysics [astro-ph]Ciencias Físicas cosmic radiation: density galaxies: starburst Astrophysics 01 natural sciences //purl.org/becyt/ford/1 [https]methods: data analysis Supporting material: FITS file Ultra-high-energy cosmic ray data analysis [Methods]Anisotropy cosmic radiation: model 010303 astronomy & astrophysics cosmic ray High Energy Astrophysical Phenomena (astro-ph.HE)Physics OBSERVATÓRIOS Settore FIS/01 - Fisica Sperimentale Astrophysics::Instrumentation and Methods for Astrophysics astroparticle physic astroparticle physics; cosmic rays; galaxies: active; galaxies: starburst; methods: data analysis Supporting material: FITS files; Astronomy and Astrophysics; Space and Planetary Science Auger observatory gamma ray: emission data analysis Supporting material: FITS file [methods]astroparticle physics Astrophysics - High Energy Astrophysical Phenomena CIENCIAS NATURALES Y EXACTAS Astrophysics - Cosmology and Nongalactic Astrophysics Cosmology and Nongalactic Astrophysics (astro-ph.CO)Active galactic nucleus active [Galaxies]Astrophysics::High Energy Astrophysical Phenomena galaxies: active Data analysis FOS: Physical sciences Starburst Cosmic ray anisotropy Astrophysics::Cosmology and Extragalactic Astrophysics Otras Ciencias Físicas GLAST cosmic rays astroparticle physics; cosmic rays; galaxies: active; galaxies: starburst; methods: data analysis Supporting material: FITS files 0103 physical sciences High Energy Physics cosmic radiation: UHE AGN Cosmic rays Astrophysics::Galaxy Astrophysics Zenith methods: data analysis Supporting material: FITS files Pierre Auger Observatory SPECTRUM 010308 nuclear & particles physics Isotropy Física Astronomy and Astrophysics //purl.org/becyt/ford/1.3 [https]Astronomy and Astrophysic methods: data analysis Galaxy flux starburst [Galaxies]Space and Planetary Science Experimental High Energy Physics Active galaxies galaxy Astroparticle physics [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]statistical

description

A new analysis of the dataset 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 EeV with zenith angles up to 80 deg 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 4.0 sigma, the highest value of the test statistic being for energies above 39 EeV. The three alternative models are favored against isotropy with 2.7-3.2 sigma significance. The origin of the indicated deviation from isotropy is examined and prospects for more sensitive future studies are discussed.

year	journal	country	edition	language
2018-02-02

10.3847/2041-8213/aaa66d http://hdl.handle.net/2066/183588