Large-scale cosmic-ray anisotropies above 4 EeV measured by the Pierre Auger Observatory

A. Aab , Pedro Abreu , Marco Aglietta , Ivone Albuquerque , Justin M Albury , Ingomar Allekotte , Alejandro Almela , Jesus Alvarez Castillo , Jaime Alvarez-Muñiz , Gioacchino Alex Anastasi , Luis Anchordoqui , Belén Andrada , Sofia Andringa , Carla Aramo , Hernán Gonzalo Asorey , Pedro Assis , Gualberto Avila , Alina Mihaela Badescu , Alexandru Balaceanu , Felicia Barbato , Ricardo Jorge Barreira Luz , Sebastian Baur , Karl-Heinz Becker , Jose A Bellido , Corinne Berat (1) , Mario Edoardo Bertaina , Xavier Bertou , Peter Biermann , Jonathan Biteau (2) , Simon G Blaess , Alberto Blanco , Jiri Blazek , Carla Bleve , Martina Boháčová , Carla Bonifazi , Nataliia Borodai , Ana Martina Botti , Jeffrey Brack , Thomas Bretz , Ariel Bridgeman , Florian Lukas Briechle , Peter Buchholz , Antonio Bueno , Stijn Buitink , Mario Buscemi , Karen S Caballero-Mora , Lorenzo Caccianiga , Laura Calcagni , Ángel Cancio , Fabrizia Canfora , Juan Miguel Carceller , Rossella Caruso , Antonella Castellina , Fernando Catalani , Gabriella Cataldi , Lorenzo Cazon , Jose Augusto Chinellato , Jiri Chudoba , Ladislav Chytka , Roger W Clay , Agustín Cobos Cerutti , Roberta Colalillo , Alan Coleman , Maria Rita Coluccia , Ruben Conceição , Giovanni Consolati , Fernando Contreras , Mathew J Cooper , Stephane Coutu , Corbin Covault , Bruno Daniel , Sergio Dasso , Kai Daumiller , Bruce R Dawson , Jarryd A Day , Rogerio M de Almeida , Sijbrand J de Jong , Giuseppe de Mauro , Joao de Mello Neto , Ivan de Mitri , Jaime de Oliveira , Vitor de Souza , Joachim Debatin , Olivier Deligny (2) , Niraj Dhital , Mary Lucia Díaz Castro , Francisco Diogo , Carola Dobrigkeit , Juan Carlos d'Olivo , Qader Dorosti , Rita dos Anjos , Maria Teresa Dova , Andrej Dundovic , Jan Ebr , Ralph Engel , Martin Erdmann , Carlos O Escobar , Alberto Etchegoyen , Heino Falcke , John Farmer , Glennys Farrar , Anderson Fauth , Norberto Fazzini , Fridtjof Feldbusch , Francesco Fenu , Luciano Pablo Ferreyro , Juan Manuel Figueira , Andrej Filipčič , Martín Miguel Freire , Toshihiro Fujii , Alan Fuster , Beatriz García , Hartmut Gemmeke , Alexandru Gherghel-Lascu , Piera Luisa Ghia (2) , Ugo Giaccari , Marco Giammarchi , Maria Giller , Dariusz Głas , Jonas Glombitza , Geraldina Golup , Mariano Gómez Berisso , Primo F Gómez Vitale , Nicolás González , Isabel Goos , Dariusz Góra , Alessio Gorgi , Marvin Gottowik , Trent D Grubb , Fausto Guarino , Germano Guedes , Eleonora Guido , Robert Halliday , Matías Rolf Hampel , Patricia Hansen , Diego Harari , Thomas A Harrison , Violet M Harvey , Andreas Haungs , Thomas Hebbeker , Dieter Heck , Philipp Heimann , Gary C Hill , Carlos Hojvat , Ewa M Holt , Piotr Homola , Jörg Hörandel , Pavel Horvath , Miroslav Hrabovský , Tim Huege , Johannes Hulsman , Antonio Insolia , Paula Gina Isar , Ingolf Jandt , Jeffrey A Johnsen , Mariela Josebachuili , Jakub Jurysek , Alex Kääpä , Karl-Heinz Kampert , Bianca Keilhauer , Nikolas Kemmerich , Julian Kemp , Hans Klages , Matthias Kleifges , Jonny Kleinfeller , Raphael Krause , Daniel Kuempel , Gasper Kukec Mezek , Alaa Kuotb Awad , Bruno L Lago , Danielle Lahurd , Rodrigo Guedes Lang , Remigiusz Legumina , Marcelo Augusto Leigui de Oliveira , Vladimir Lenok , Antoine Letessier-Selvon (3) , Isabelle Lhenry-Yvon (2) , Domenico Lo Presti , Luis Lopes , Rebeca López , Aida López Casado , Ryan Lorek , Quentin Luce (2) , Agustin Lucero , Max Malacari , Manuela Mallamaci , Giovanni Mancarella , Dusan Mandat , Paul Mantsch , Analisa Mariazzi , Ioana Mariş , Giovanni Marsella , Daniele Martello , Humberto Martinez , Oscar Martínez Bravo , Hermann-Josef Mathes , Sebastian Mathys , James Matthews , Giorgio Matthiae , Eric Mayotte , Peter Mazur , Gustavo Medina-Tanco , Diego Melo , Alexander Menshikov , Kevin-Druis Merenda , Stanislav Michal , Maria Isabel Micheletti , Lukas Middendorf , Lino Miramonti , Bogdan Mitrica , Daniela Mockler , Silvia Mollerach , François Montanet (1) , Carlo Morello , Giovanni Morlino , Miguel Mostafá , Ana L Müller , Marcio Aparecido Muller , Sarah Müller , Roberto Mussa , Lukas Nellen , Phong H Nguyen , Mihai Niculescu-Oglinzanu , Marcus Niechciol , Dave Nitz , Dalibor Nosek , Vladimir Novotny , Libor Nožka , Achille Nucita , Luis Núñez , Angela Olinto , Miroslav Palatka , Juan Pallotta , Philipp Papenbreer , Gonzalo Parente , Alejandra Parra , Miroslav Pech , Francisco Pedreira , Jan Pękala , Rodrigo Pelayo , Jesús Peña-Rodriguez , Luiz Augusto Pereira , Matías Perlin , Lorenzo Perrone , Christine Peters , Sergio Petrera , Jamyang Phuntsok , Tanguy Pierog , Mário Pimenta , Valerio Pirronello , Manuel Platino , Jason Poh , Bjarni Pont , Czeslaw Porowski , Raul Ribeiro Prado , Paolo Privitera , Michael Prouza , Andrew Puyleart , Sven Querchfeld , Sean Quinn , Raúl Ramos-Pollan , Julian Rautenberg , Diego Ravignani , Maximilian Reininghaus , Jan Ridky , Felix Riehn , Markus Risse , Pablo Ristori , Vincenzo Rizi , Washington Rodrigues de Carvalho , Jorge Rubén Rodriguez Rojo , Matías J Roncoroni , Markus Roth , Esteban Roulet , Adrian Rovero , Philip Ruehl , Steven J Saffi , Alexandra Saftoiu , Francesco Salamida , Humberto Salazar , Ahmed Saleh , Gaetano Salina , Federico Sánchez , Edivaldo Moura Santos , Eva Santos , Fred Sarazin , Raul Sarmento , Christian Sarmiento-Cano , Ricardo Sato , Pierpaolo Savina , Markus Schauer , Viviana Scherini , Harald Schieler , Martin Schimassek , Michael Schimp , David Schmidt , Olaf Scholten , Petr Schovánek , Frank G Schröder , Sonja Schröder , Johannes Schumacher , Sergio Sciutto , Ronald C Shellard , Guenter Sigl , Gaia Silli , Octavian Sima , Radomir Šmída , Gregory Snow , Paul Sommers , Jorge F Soriano , Julien Souchard (1) , Ruben Squartini , Denis Stanca , Samo Stanič , Jaroslaw Stasielak , Patrick Stassi (1) , Mikhail Stolpovskiy (1) , Alexander Streich , Federico Suarez , Mauricio Suárez-Durán , Tristan Sudholz , Tiina Suomijärvi (2) , a Daniel Supanitsky , Jan Šupík , Zbigniew Szadkowski , Alvaro Taboada , Oscar Alejandro Taborda , Alex Tapia , Charles Timmermans , Carlos J Todero Peixoto , Bernardo Tomé , Guillermo Torralba Elipe , Petr Travnicek , Marta Trini , Matias Tueros , Ralf Ulrich , Michael Unger , Martin Urban , Jose F Valdés Galicia , Ines Valiño , Laura Valore , Patrick van Bodegom , Ad M van den Berg , Arjen van Vliet , Enrique Varela , Bernardo Vargas Cárdenas , Ricardo Vázquez , Darko Veberič , Cynthia Ventura , Indira D Vergara Quispe , Valerio Verzi , Jakub Vicha , Luis Villaseñor , Serguei Vorobiov , Hernan Wahlberg , Oscar Wainberg , Alan Watson , Marc Weber , Andreas Weindl , Michał Wiedeński , Lawrence Wiencke , Henryk Wilczyński , Marcus Wirtz , David Wittkowski , Brian Wundheiler , Lili Yang , Alexey Yushkov , Enrique Zas , Danilo Zavrtanik , Marko Zavrtanik , Lukas Zehrer , Arnulfo Zepeda , Benedikt Zimmermann , Michael Ziolkowski , Zizhao Zong (2) , Francesca Zuccarello

1 LPSC - Laboratoire de Physique Subatomique et de Cosmologie
2 IPNO - Institut de Physique Nucléaire d'Orsay
3 LPNHE (UMR_7585) - Laboratoire de Physique Nucléaire et de Hautes Énergies

We present a detailed study of the large-scale anisotropies of cosmic rays with energies above 4 EeV measured using the Pierre Auger Observatory. For the energy bins [4, 8] EeV and E ≥ 8 EeV, the most significant signal is a dipolar modulation in R.A. at energies above 8 EeV, as previously reported. In this paper we further scrutinize the highest-energy bin by splitting it into three energy ranges. We find that the amplitude of the dipole increases with energy above 4 EeV. The growth can be fitted with a power law with index β = 0.79 ± 0.19. The directions of the dipoles are consistent with an extragalactic origin of these anisotropies at all the energies considered. Additionally, we have estimated the quadrupolar components of the anisotropy: they are not statistically significant. We discuss the results in the context of the predictions from different models for the distribution of ultrahigh-energy sources and cosmic magnetic fields.

Mots clés: astroparticle physics; cosmic rays; cosmic radiation: anisotropy; cosmic radiation: UHE; observatory; dipole; Auger; magnetic field; modulation; splitting

Domaines: Astrophysique [astro-ph]

A. Aab, Pedro Abreu, Marco Aglietta, Ivone Albuquerque, Justin M Albury, et al.. Large-scale cosmic-ray anisotropies above 4 EeV measured by the Pierre Auger Observatory. Astrophys.J., 2018, 868 (1), pp.4. ⟨10.3847/1538-4357/aae689⟩. ⟨hal-01861883⟩