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, M. 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 & 372 others 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, A. 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, A. 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. Mariş, 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, G. 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. Pkala, 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, A. 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, F. Zuccarello

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26 Citations (Scopus)

Abstract

A 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 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 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.

Original languageAmerican English
Article numberL29
JournalAstrophysical Journal Letters
Volume853
Issue number2
DOIs
StatePublished - 1 Feb 2018
Externally publishedYes

Fingerprint

isotropy
cosmic ray
arrivals
cosmic rays
indication
anisotropy
energy
catalogs
sky
likelihood ratio
starburst galaxies
zenith angle
zenith
active galactic nuclei
observatories
astrophysics
emitters
observatory
comparison
statistics

Keywords

  • astroparticle physics
  • cosmic rays
  • galaxies: active
  • galaxies: starburst
  • methods: data analysis Supporting material: FITS files

Cite this

Aab, A. ; Abreu, P. ; Aglietta, M. ; Albuquerque, I. F.M. ; Allekotte, I. ; Almela, A. ; Alvarez Castillo, J. ; Alvarez-Muñiz, J. ; Anastasi, G. A. ; Anchordoqui, L. ; Andrada, B. ; Andringa, S. ; Aramo, C. ; Arsene, N. ; Asorey, H. ; Assis, P. ; Avila, G. ; Badescu, A. M. ; Balaceanu, A. ; Barbato, F. ; Barreira Luz, R. J. ; Beatty, J. J. ; Becker, K. H. ; Bellido, J. A. ; Berat, C. ; Bertaina, M. E. ; Bertou, X. ; Biermann, P. L. ; Biteau, J. ; Blaess, S. G. ; Blanco, A. ; Blazek, J. ; Bleve, C. ; Boháčová, M. ; Bonifazi, C. ; Borodai, N. ; Botti, A. M. ; Brack, J. ; Brancus, I. ; Bretz, T. ; Bridgeman, A. ; Briechle, F. L. ; Buchholz, P. ; Bueno, A. ; Buitink, S. ; Buscemi, M. ; Caballero-Mora, K. S. ; Caccianiga, L. ; Cancio, A. ; Canfora, F. ; Caruso, R. ; Castellina, A. ; Catalani, F. ; Cataldi, G. ; Cazon, L. ; Chavez, A. G. ; Chinellato, J. A. ; Chudoba, J. ; Clay, R. W. ; Cobos Cerutti, A. C. ; Colalillo, R. ; Coleman, A. ; Collica, L. ; Coluccia, M. R. ; Conceição, R. ; Consolati, G. ; Contreras, F. ; Cooper, M. J. ; Coutu, S. ; Covault, C. E. ; Cronin, J. ; D'Amico, S. ; Daniel, B. ; Dasso, S. ; Daumiller, K. ; Dawson, B. R. ; De Almeida, R. M. ; De Jong, S. J. ; De Mauro, G. ; De Mello Neto, J. R.T. ; De Mitri, I. ; De Oliveira, J. ; De Souza, V. ; Debatin, J. ; Deligny, O. ; Díaz Castro, M. L. ; Diogo, F. ; Dobrigkeit, C. ; D'Olivo, J. C. ; Dorosti, Q. ; Dos Anjos, R. C. ; Dova, M. T. ; Dundovic, A. ; Ebr, J. ; Engel, R. ; Erdmann, M. ; Erfani, M. ; Escobar, C. O. ; Espadanal, J. ; Etchegoyen, A. ; Falcke, H. ; Farmer, J. ; Farrar, G. ; Fauth, A. C. ; Fazzini, N. ; Fenu, F. ; Fick, B. ; Figueira, J. M. ; Filipčič, A. ; Freire, M. M. ; Fujii, T. ; Fuster, A. ; Gaïor, R. ; García, B. ; Gaté, F. ; Gemmeke, H. ; Gherghel-Lascu, A. ; Ghia, P. L. ; Giaccari, U. ; Giammarchi, M. ; Giller, M. ; Głas, D. ; Glaser, C. ; Golup, G. ; Gómez Berisso, M. ; Gómez Vitale, P. F. ; González, N. ; Gorgi, A. ; Grillo, A. F. ; Grubb, T. D. ; Guarino, F. ; Guedes, G. P. ; Halliday, R. ; Hampel, M. R. ; Hansen, P. ; Harari, D. ; Harrison, T. A. ; Haungs, A. ; Hebbeker, T. ; Heck, D. ; Heimann, P. ; Herve, A. E. ; Hill, G. C. ; Hojvat, C. ; Holt, E. ; Homola, P. ; Hörandel, J. R. ; Horvath, P. ; Hrabovský, M. ; Huege, T. ; Hulsman, J. ; Insolia, A. ; Isar, P. G. ; Jandt, I. ; Johnsen, J. A. ; Josebachuili, M. ; Jurysek, J. ; Kääpä, A. ; Kambeitz, O. ; Kampert, K. H. ; Keilhauer, B. ; Kemmerich, N. ; Kemp, E. ; Kemp, J. ; Kieckhafer, R. M. ; Klages, H. O. ; Kleifges, M. ; Kleinfeller, J. ; Krause, R. ; Krohm, N. ; Kuempel, D. ; Kukec Mezek, G. ; Kunka, N. ; Kuotb Awad, A. ; Lago, B. L. ; Lahurd, D. ; Lang, R. G. ; Lauscher, M. ; Legumina, R. ; Leigui De Oliveira, M. A. ; Letessier-Selvon, A. ; Lhenry-Yvon, I. ; Link, K. ; Lo Presti, D. ; Lopes, L. ; López, R. ; López Casado, A. ; Lorek, R. ; Luce, Q. ; Lucero, A. ; Malacari, M. ; Mallamaci, M. ; Mandat, D. ; Mantsch, P. ; Mariazzi, A. G. ; Mariş, I. C. ; Marsella, G. ; Martello, D. ; Martinez, H. ; Martínez Bravo, O. ; Masías Meza, J. J. ; Mathes, H. J. ; Mathys, S. ; Matthews, J. ; Matthiae, G. ; Mayotte, E. ; Mazur, P. O. ; Medina, C. ; Medina-Tanco, G. ; Melo, D. ; Menshikov, A. ; Merenda, K. D. ; Michal, S. ; Micheletti, M. I. ; Middendorf, L. ; Miramonti, L. ; Mitrica, B. ; Mockler, D. ; Mollerach, S. ; Montanet, F. ; Morello, C. ; Morlino, G. ; Mostafá, M. ; Müller, A. L. ; Müller, G. ; Muller, M. A. ; Müller, S. ; Mussa, R. ; Naranjo, I. ; Nellen, L. ; Nguyen, P. H. ; Niculescu-Oglinzanu, M. ; Niechciol, M. ; Niemietz, L. ; Niggemann, T. ; Nitz, D. ; Nosek, D. ; Novotny, V. ; Nožka, L. ; Núñez, L. A. ; Oikonomou, F. ; Olinto, A. ; Palatka, M. ; Pallotta, J. ; Papenbreer, P. ; Parente, G. ; Parra, A. ; Paul, T. ; Pech, M. ; Pedreira, F. ; Pkala, J. ; Pelayo, R. ; Peña-Rodriguez, J. ; Pereira, L. A.S. ; Perlin, M. ; Perrone, L. ; Peters, C. ; Petrera, S. ; Phuntsok, J. ; Pierog, T. ; Pimenta, M. ; Pirronello, V. ; Platino, M. ; Plum, M. ; Poh, J. ; Porowski, C. ; Prado, R. R. ; Privitera, P. ; Prouza, M. ; Quel, E. J. ; Querchfeld, S. ; Quinn, S. ; Ramos-Pollan, R. ; Rautenberg, J. ; Ravignani, D. ; Ridky, J. ; Riehn, F. ; Risse, M. ; Ristori, P. ; Rizi, V. ; Rodrigues De Carvalho, W. ; Rodriguez Fernandez, G. ; Rodriguez Rojo, J. ; Roncoroni, M. J. ; Roth, M. ; Roulet, E. ; Rovero, A. C. ; Ruehl, P. ; Saffi, S. J. ; Saftoiu, A. ; Salamida, F. ; Salazar, H. ; Saleh, A. ; Salina, G. ; Sánchez, F. ; Sanchez-Lucas, P. ; Santos, E. M. ; Santos, E. ; Sarazin, F. ; Sarmento, R. ; Sarmiento-Cano, C. ; Sato, R. ; Schauer, M. ; Scherini, V. ; Schieler, H. ; Schimp, M. ; Schmidt, D. ; Scholten, O. ; Schovánek, P. ; Schröder, F. G. ; Schröder, S. ; Schulz, A. ; Schumacher, J. ; Sciutto, S. J. ; Segreto, A. ; Shadkam, A. ; Shellard, R. C. ; Sigl, G. ; Silli, G. ; Šmída, R. ; Snow, G. R. ; Sommers, P. ; Sonntag, S. ; Soriano, J. F. ; Squartini, R. ; Stanca, D. ; Stanič, S. ; Stasielak, J. ; Stassi, P. ; Stolpovskiy, M. ; Strafella, F. ; Streich, A. ; Suarez, F. ; Suarez Durán, M. ; Sudholz, T. ; Suomijärvi, T. ; Supanitsky, A. D. ; Šupík, J. ; Swain, J. ; Szadkowski, Z. ; Taboada, A. ; Taborda, O. A. ; Theodoro, V. M. ; Timmermans, C. ; Todero Peixoto, C. J. ; Tomankova, L. ; Tomé, B. ; Torralba Elipe, G. ; Travnicek, P. ; Trini, M. ; Ulrich, R. ; Unger, M. ; Urban, M. ; Valdés Galicia, J. F. ; Valiño, I. ; Valore, L. ; Van Aar, G. ; Van Bodegom, P. ; Van Den Berg, A. M. ; Van Vliet, A. ; Varela, E. ; Vargas Cárdenas, B. ; Vázquez, R. A. ; Veberič, D. ; Ventura, C. ; Vergara Quispe, I. D. ; Verzi, V. ; Vicha, J. ; Villaseñor, L. ; Vorobiov, S. ; Wahlberg, H. ; Wainberg, O. ; Walz, D. ; Watson, A. A. ; Weber, M. ; Weindl, A. ; Wiedeński, M. ; Wiencke, L. ; Wilczyński, H. ; Wirtz, M. ; Wittkowski, D. ; Wundheiler, B. ; Yang, L. ; Yushkov, A. ; Zas, E. ; Zavrtanik, D. ; Zavrtanik, M. ; Zepeda, A. ; Zimmermann, B. ; Ziolkowski, M. ; Zong, Z. ; Zuccarello, F. / An Indication of Anisotropy in Arrival Directions of Ultra-high-energy Cosmic Rays through Comparison to the Flux Pattern of Extragalactic Gamma-Ray Sources. In: Astrophysical Journal Letters. 2018 ; Vol. 853, No. 2.
@article{ece83f4f86894da5a2193f5731cfba6a,
title = "An Indication of Anisotropy in Arrival Directions of Ultra-high-energy Cosmic Rays through Comparison to the Flux Pattern of Extragalactic Gamma-Ray Sources",
abstract = "A 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 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 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.",
keywords = "astroparticle physics, cosmic rays, galaxies: active, galaxies: starburst, methods: data analysis Supporting material: FITS files",
author = "A. Aab and P. Abreu and M. Aglietta and Albuquerque, {I. F.M.} and I. Allekotte and A. Almela and {Alvarez Castillo}, J. and J. Alvarez-Mu{\~n}iz and Anastasi, {G. A.} and L. Anchordoqui and B. Andrada and S. Andringa and C. Aramo and N. Arsene and H. Asorey and P. Assis and G. Avila and Badescu, {A. M.} and A. Balaceanu and F. Barbato and {Barreira Luz}, {R. J.} and Beatty, {J. J.} and Becker, {K. H.} and Bellido, {J. A.} and C. Berat and Bertaina, {M. E.} and X. Bertou and Biermann, {P. L.} and J. Biteau and Blaess, {S. G.} and A. Blanco and J. Blazek and C. Bleve and M. Boh{\'a}čov{\'a} and C. Bonifazi and N. Borodai and Botti, {A. M.} and J. Brack and I. Brancus and T. Bretz and A. Bridgeman and Briechle, {F. L.} and P. Buchholz and A. Bueno and S. Buitink and M. Buscemi and Caballero-Mora, {K. S.} and L. Caccianiga and A. Cancio and F. Canfora and R. Caruso and A. Castellina and F. Catalani and G. Cataldi and L. Cazon and Chavez, {A. G.} and Chinellato, {J. A.} and J. Chudoba and Clay, {R. W.} and {Cobos Cerutti}, {A. C.} and R. Colalillo and A. Coleman and L. Collica and Coluccia, {M. R.} and R. Concei{\cc}{\~a}o and G. Consolati and F. Contreras and Cooper, {M. J.} and S. Coutu and Covault, {C. E.} and J. Cronin and S. D'Amico and B. Daniel and S. Dasso and K. Daumiller and Dawson, {B. R.} and {De Almeida}, {R. M.} and {De Jong}, {S. J.} and {De Mauro}, G. and {De Mello Neto}, {J. R.T.} and {De Mitri}, I. and {De Oliveira}, J. and {De Souza}, V. and J. Debatin and O. Deligny and {D{\'i}az Castro}, {M. L.} and F. Diogo and C. Dobrigkeit and D'Olivo, {J. C.} and Q. Dorosti and {Dos Anjos}, {R. C.} and Dova, {M. T.} and A. Dundovic and J. Ebr and R. Engel and M. Erdmann and M. Erfani and Escobar, {C. O.} and J. Espadanal and A. Etchegoyen and H. Falcke and J. Farmer and G. Farrar and Fauth, {A. C.} and N. Fazzini and F. Fenu and B. Fick and Figueira, {J. M.} and A. Filipčič and Freire, {M. M.} and T. Fujii and A. Fuster and R. Ga{\"i}or and B. Garc{\'i}a and F. Gat{\'e} and H. Gemmeke and A. Gherghel-Lascu and Ghia, {P. L.} and U. Giaccari and M. Giammarchi and M. Giller and D. Głas and C. Glaser and G. Golup and {G{\'o}mez Berisso}, M. and {G{\'o}mez Vitale}, {P. F.} and N. Gonz{\'a}lez and A. Gorgi and Grillo, {A. F.} and Grubb, {T. D.} and F. Guarino and Guedes, {G. P.} and R. Halliday and Hampel, {M. R.} and P. Hansen and D. Harari and Harrison, {T. A.} and A. Haungs and T. Hebbeker and D. Heck and P. Heimann and Herve, {A. E.} and Hill, {G. C.} and C. Hojvat and E. Holt and P. Homola and H{\"o}randel, {J. R.} and P. Horvath and M. Hrabovsk{\'y} and T. Huege and J. Hulsman and A. Insolia and Isar, {P. G.} and I. Jandt and Johnsen, {J. A.} and M. Josebachuili and J. Jurysek and A. K{\"a}{\"a}p{\"a} and O. Kambeitz and Kampert, {K. H.} and B. Keilhauer and N. Kemmerich and E. Kemp and J. Kemp and Kieckhafer, {R. M.} and Klages, {H. O.} and M. Kleifges and J. Kleinfeller and R. Krause and N. Krohm and D. Kuempel and {Kukec Mezek}, G. and N. Kunka and {Kuotb Awad}, A. and Lago, {B. L.} and D. Lahurd and Lang, {R. G.} and M. Lauscher and R. Legumina and {Leigui De Oliveira}, {M. A.} and A. Letessier-Selvon and I. Lhenry-Yvon and K. Link and {Lo Presti}, D. and L. Lopes and R. L{\'o}pez and {L{\'o}pez Casado}, A. and R. Lorek and Q. Luce and A. Lucero and M. Malacari and M. Mallamaci and D. Mandat and P. Mantsch and Mariazzi, {A. G.} and Mariş, {I. C.} and G. Marsella and D. Martello and H. Martinez and {Mart{\'i}nez Bravo}, O. and {Mas{\'i}as Meza}, {J. J.} and Mathes, {H. J.} and S. Mathys and J. Matthews and G. Matthiae and E. Mayotte and Mazur, {P. O.} and C. Medina and G. Medina-Tanco and D. Melo and A. Menshikov and Merenda, {K. D.} and S. Michal and Micheletti, {M. I.} and L. Middendorf and L. Miramonti and B. Mitrica and D. Mockler and S. Mollerach and F. Montanet and C. Morello and G. Morlino and M. Mostaf{\'a} and M{\"u}ller, {A. L.} and G. M{\"u}ller and Muller, {M. A.} and S. M{\"u}ller and R. Mussa and I. Naranjo and L. Nellen and Nguyen, {P. H.} and M. Niculescu-Oglinzanu and M. Niechciol and L. Niemietz and T. Niggemann and D. Nitz and D. Nosek and V. Novotny and L. Nožka and N{\'u}{\~n}ez, {L. A.} and F. Oikonomou and A. Olinto and M. Palatka and J. Pallotta and P. Papenbreer and G. Parente and A. Parra and T. Paul and M. Pech and F. Pedreira and J. Pkala and R. Pelayo and J. Pe{\~n}a-Rodriguez and Pereira, {L. A.S.} and M. Perlin and L. Perrone and C. Peters and S. Petrera and J. Phuntsok and T. Pierog and M. Pimenta and V. Pirronello and M. Platino and M. Plum and J. Poh and C. Porowski and Prado, {R. R.} and P. Privitera and M. Prouza and Quel, {E. J.} and S. Querchfeld and S. Quinn and R. Ramos-Pollan and J. Rautenberg and D. Ravignani and J. Ridky and F. Riehn and M. Risse and P. Ristori and V. Rizi and {Rodrigues De Carvalho}, W. and {Rodriguez Fernandez}, G. and {Rodriguez Rojo}, J. and Roncoroni, {M. J.} and M. Roth and E. Roulet and Rovero, {A. C.} and P. Ruehl and Saffi, {S. J.} and A. Saftoiu and F. Salamida and H. Salazar and A. Saleh and G. Salina and F. S{\'a}nchez and P. Sanchez-Lucas and Santos, {E. M.} and E. Santos and F. Sarazin and R. Sarmento and C. Sarmiento-Cano and R. Sato and M. Schauer and V. Scherini and H. Schieler and M. Schimp and D. Schmidt and O. Scholten and P. Schov{\'a}nek and Schr{\"o}der, {F. G.} and S. Schr{\"o}der and A. Schulz and J. Schumacher and Sciutto, {S. J.} and A. Segreto and A. Shadkam and Shellard, {R. C.} and G. Sigl and G. Silli and R. Šm{\'i}da and Snow, {G. R.} and P. Sommers and S. Sonntag and Soriano, {J. F.} and R. Squartini and D. Stanca and S. Stanič and J. Stasielak and P. Stassi and M. Stolpovskiy and F. Strafella and A. Streich and F. Suarez and {Suarez Dur{\'a}n}, M. and T. Sudholz and T. Suomij{\"a}rvi and Supanitsky, {A. D.} and J. Šup{\'i}k and J. Swain and Z. Szadkowski and A. Taboada and Taborda, {O. A.} and Theodoro, {V. M.} and C. Timmermans and {Todero Peixoto}, {C. J.} and L. Tomankova and B. Tom{\'e} and {Torralba Elipe}, G. and P. Travnicek and M. Trini and R. Ulrich and M. Unger and M. Urban and {Vald{\'e}s Galicia}, {J. F.} and I. Vali{\~n}o and L. Valore and {Van Aar}, G. and {Van Bodegom}, P. and {Van Den Berg}, {A. M.} and {Van Vliet}, A. and E. Varela and {Vargas C{\'a}rdenas}, B. and V{\'a}zquez, {R. A.} and D. Veberič and C. Ventura and {Vergara Quispe}, {I. D.} and V. Verzi and J. Vicha and L. Villase{\~n}or and S. Vorobiov and H. Wahlberg and O. Wainberg and D. Walz and Watson, {A. A.} and M. Weber and A. Weindl and M. Wiedeński and L. Wiencke and H. Wilczyński and M. Wirtz and D. Wittkowski and B. Wundheiler and L. Yang and A. Yushkov and E. Zas and D. Zavrtanik and M. Zavrtanik and A. Zepeda and B. Zimmermann and M. Ziolkowski and Z. Zong and F. Zuccarello",
year = "2018",
month = "2",
day = "1",
doi = "10.3847/2041-8213/aaa66d",
language = "American English",
volume = "853",
journal = "Astrophysical Journal Letters",
issn = "2041-8205",
publisher = "IOP Publishing Ltd.",
number = "2",

}

Aab, A, Abreu, P, Aglietta, M, Albuquerque, IFM, Allekotte, I, Almela, A, Alvarez Castillo, J, Alvarez-Muñiz, J, Anastasi, GA, Anchordoqui, L, Andrada, B, Andringa, S, Aramo, C, Arsene, N, Asorey, H, Assis, P, Avila, G, Badescu, AM, Balaceanu, A, Barbato, F, Barreira Luz, RJ, Beatty, JJ, Becker, KH, Bellido, JA, Berat, C, Bertaina, ME, Bertou, X, Biermann, PL, Biteau, J, Blaess, SG, Blanco, A, Blazek, J, Bleve, C, Boháčová, M, Bonifazi, C, Borodai, N, Botti, AM, Brack, J, Brancus, I, Bretz, T, Bridgeman, A, Briechle, FL, Buchholz, P, Bueno, A, Buitink, S, Buscemi, M, Caballero-Mora, KS, Caccianiga, L, Cancio, A, Canfora, F, Caruso, R, Castellina, A, Catalani, F, Cataldi, G, Cazon, L, Chavez, AG, Chinellato, JA, Chudoba, J, Clay, RW, Cobos Cerutti, AC, Colalillo, R, Coleman, A, Collica, L, Coluccia, MR, Conceição, R, Consolati, G, Contreras, F, Cooper, MJ, Coutu, S, Covault, CE, Cronin, J, D'Amico, S, Daniel, B, Dasso, S, Daumiller, K, Dawson, BR, De Almeida, RM, De Jong, SJ, De Mauro, G, De Mello Neto, JRT, De Mitri, I, De Oliveira, J, De Souza, V, Debatin, J, Deligny, O, Díaz Castro, ML, Diogo, F, Dobrigkeit, C, D'Olivo, JC, Dorosti, Q, Dos Anjos, RC, Dova, MT, Dundovic, A, Ebr, J, Engel, R, Erdmann, M, Erfani, M, Escobar, CO, Espadanal, J, Etchegoyen, A, Falcke, H, Farmer, J, Farrar, G, Fauth, AC, Fazzini, N, Fenu, F, Fick, B, Figueira, JM, Filipčič, A, Freire, MM, Fujii, T, Fuster, A, Gaïor, R, García, B, Gaté, F, Gemmeke, H, Gherghel-Lascu, A, Ghia, PL, Giaccari, U, Giammarchi, M, Giller, M, Głas, D, Glaser, C, Golup, G, Gómez Berisso, M, Gómez Vitale, PF, González, N, Gorgi, A, Grillo, AF, Grubb, TD, Guarino, F, Guedes, GP, Halliday, R, Hampel, MR, Hansen, P, Harari, D, Harrison, TA, Haungs, A, Hebbeker, T, Heck, D, Heimann, P, Herve, AE, Hill, GC, Hojvat, C, Holt, E, Homola, P, Hörandel, JR, Horvath, P, Hrabovský, M, Huege, T, Hulsman, J, Insolia, A, Isar, PG, Jandt, I, Johnsen, JA, Josebachuili, M, Jurysek, J, Kääpä, A, Kambeitz, O, Kampert, KH, Keilhauer, B, Kemmerich, N, Kemp, E, Kemp, J, Kieckhafer, RM, Klages, HO, Kleifges, M, Kleinfeller, J, Krause, R, Krohm, N, Kuempel, D, Kukec Mezek, G, Kunka, N, Kuotb Awad, A, Lago, BL, Lahurd, D, Lang, RG, Lauscher, M, Legumina, R, Leigui De Oliveira, MA, Letessier-Selvon, A, Lhenry-Yvon, I, Link, K, Lo Presti, D, Lopes, L, López, R, López Casado, A, Lorek, R, Luce, Q, Lucero, A, Malacari, M, Mallamaci, M, Mandat, D, Mantsch, P, Mariazzi, AG, Mariş, IC, Marsella, G, Martello, D, Martinez, H, Martínez Bravo, O, Masías Meza, JJ, Mathes, HJ, Mathys, S, Matthews, J, Matthiae, G, Mayotte, E, Mazur, PO, Medina, C, Medina-Tanco, G, Melo, D, Menshikov, A, Merenda, KD, Michal, S, Micheletti, MI, Middendorf, L, Miramonti, L, Mitrica, B, Mockler, D, Mollerach, S, Montanet, F, Morello, C, Morlino, G, Mostafá, M, Müller, AL, Müller, G, Muller, MA, Müller, S, Mussa, R, Naranjo, I, Nellen, L, Nguyen, PH, Niculescu-Oglinzanu, M, Niechciol, M, Niemietz, L, Niggemann, T, Nitz, D, Nosek, D, Novotny, V, Nožka, L, Núñez, LA, Oikonomou, F, Olinto, A, Palatka, M, Pallotta, J, Papenbreer, P, Parente, G, Parra, A, Paul, T, Pech, M, Pedreira, F, Pkala, J, Pelayo, R, Peña-Rodriguez, J, Pereira, LAS, Perlin, M, Perrone, L, Peters, C, Petrera, S, Phuntsok, J, Pierog, T, Pimenta, M, Pirronello, V, Platino, M, Plum, M, Poh, J, Porowski, C, Prado, RR, Privitera, P, Prouza, M, Quel, EJ, Querchfeld, S, Quinn, S, Ramos-Pollan, R, Rautenberg, J, Ravignani, D, Ridky, J, Riehn, F, Risse, M, Ristori, P, Rizi, V, Rodrigues De Carvalho, W, Rodriguez Fernandez, G, Rodriguez Rojo, J, Roncoroni, MJ, Roth, M, Roulet, E, Rovero, AC, Ruehl, P, Saffi, SJ, Saftoiu, A, Salamida, F, Salazar, H, Saleh, A, Salina, G, Sánchez, F, Sanchez-Lucas, P, Santos, EM, Santos, E, Sarazin, F, Sarmento, R, Sarmiento-Cano, C, Sato, R, Schauer, M, Scherini, V, Schieler, H, Schimp, M, Schmidt, D, Scholten, O, Schovánek, P, Schröder, FG, Schröder, S, Schulz, A, Schumacher, J, Sciutto, SJ, Segreto, A, Shadkam, A, Shellard, RC, Sigl, G, Silli, G, Šmída, R, Snow, GR, Sommers, P, Sonntag, S, Soriano, JF, Squartini, R, Stanca, D, Stanič, S, Stasielak, J, Stassi, P, Stolpovskiy, M, Strafella, F, Streich, A, Suarez, F, Suarez Durán, M, Sudholz, T, Suomijärvi, T, Supanitsky, AD, Šupík, J, Swain, J, Szadkowski, Z, Taboada, A, Taborda, OA, Theodoro, VM, Timmermans, C, Todero Peixoto, CJ, Tomankova, L, Tomé, B, Torralba Elipe, G, Travnicek, P, Trini, M, Ulrich, R, Unger, M, Urban, M, Valdés Galicia, JF, Valiño, I, Valore, L, Van Aar, G, Van Bodegom, P, Van Den Berg, AM, Van Vliet, A, Varela, E, Vargas Cárdenas, B, Vázquez, RA, Veberič, D, Ventura, C, Vergara Quispe, ID, Verzi, V, Vicha, J, Villaseñor, L, Vorobiov, S, Wahlberg, H, Wainberg, O, Walz, D, Watson, AA, Weber, M, Weindl, A, Wiedeński, M, Wiencke, L, Wilczyński, H, Wirtz, M, Wittkowski, D, Wundheiler, B, Yang, L, Yushkov, A, Zas, E, Zavrtanik, D, Zavrtanik, M, Zepeda, A, Zimmermann, B, Ziolkowski, M, Zong, Z & Zuccarello, F 2018, 'An Indication of Anisotropy in Arrival Directions of Ultra-high-energy Cosmic Rays through Comparison to the Flux Pattern of Extragalactic Gamma-Ray Sources', Astrophysical Journal Letters, vol. 853, no. 2, L29. https://doi.org/10.3847/2041-8213/aaa66d

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

In: Astrophysical Journal Letters, Vol. 853, No. 2, L29, 01.02.2018.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - An Indication of Anisotropy in Arrival Directions of Ultra-high-energy Cosmic Rays through Comparison to the Flux Pattern of Extragalactic Gamma-Ray Sources

AU - Aab, A.

AU - Abreu, P.

AU - Aglietta, M.

AU - Albuquerque, I. F.M.

AU - Allekotte, I.

AU - Almela, A.

AU - Alvarez Castillo, J.

AU - Alvarez-Muñiz, J.

AU - Anastasi, G. A.

AU - Anchordoqui, L.

AU - Andrada, B.

AU - Andringa, S.

AU - Aramo, C.

AU - Arsene, N.

AU - Asorey, H.

AU - Assis, P.

AU - Avila, G.

AU - Badescu, A. M.

AU - Balaceanu, A.

AU - Barbato, F.

AU - Barreira Luz, R. J.

AU - Beatty, J. J.

AU - Becker, K. H.

AU - Bellido, J. A.

AU - Berat, C.

AU - Bertaina, M. E.

AU - Bertou, X.

AU - Biermann, P. L.

AU - Biteau, J.

AU - Blaess, S. G.

AU - Blanco, A.

AU - Blazek, J.

AU - Bleve, C.

AU - Boháčová, M.

AU - Bonifazi, C.

AU - Borodai, N.

AU - Botti, A. M.

AU - Brack, J.

AU - Brancus, I.

AU - Bretz, T.

AU - Bridgeman, A.

AU - Briechle, F. L.

AU - Buchholz, P.

AU - Bueno, A.

AU - Buitink, S.

AU - Buscemi, M.

AU - Caballero-Mora, K. S.

AU - Caccianiga, L.

AU - Cancio, A.

AU - Canfora, F.

AU - Caruso, R.

AU - Castellina, A.

AU - Catalani, F.

AU - Cataldi, G.

AU - Cazon, L.

AU - Chavez, A. G.

AU - Chinellato, J. A.

AU - Chudoba, J.

AU - Clay, R. W.

AU - Cobos Cerutti, A. C.

AU - Colalillo, R.

AU - Coleman, A.

AU - Collica, L.

AU - Coluccia, M. R.

AU - Conceição, R.

AU - Consolati, G.

AU - Contreras, F.

AU - Cooper, M. J.

AU - Coutu, S.

AU - Covault, C. E.

AU - Cronin, J.

AU - D'Amico, S.

AU - Daniel, B.

AU - Dasso, S.

AU - Daumiller, K.

AU - Dawson, B. R.

AU - De Almeida, R. M.

AU - De Jong, S. J.

AU - De Mauro, G.

AU - De Mello Neto, J. R.T.

AU - De Mitri, I.

AU - De Oliveira, J.

AU - De Souza, V.

AU - Debatin, J.

AU - Deligny, O.

AU - Díaz Castro, M. L.

AU - Diogo, F.

AU - Dobrigkeit, C.

AU - D'Olivo, J. C.

AU - Dorosti, Q.

AU - Dos Anjos, R. C.

AU - Dova, M. T.

AU - Dundovic, A.

AU - Ebr, J.

AU - Engel, R.

AU - Erdmann, M.

AU - Erfani, M.

AU - Escobar, C. O.

AU - Espadanal, J.

AU - Etchegoyen, A.

AU - Falcke, H.

AU - Farmer, J.

AU - Farrar, G.

AU - Fauth, A. C.

AU - Fazzini, N.

AU - Fenu, F.

AU - Fick, B.

AU - Figueira, J. M.

AU - Filipčič, A.

AU - Freire, M. M.

AU - Fujii, T.

AU - Fuster, A.

AU - Gaïor, R.

AU - García, B.

AU - Gaté, F.

AU - Gemmeke, H.

AU - Gherghel-Lascu, A.

AU - Ghia, P. L.

AU - Giaccari, U.

AU - Giammarchi, M.

AU - Giller, M.

AU - Głas, D.

AU - Glaser, C.

AU - Golup, G.

AU - Gómez Berisso, M.

AU - Gómez Vitale, P. F.

AU - González, N.

AU - Gorgi, A.

AU - Grillo, A. F.

AU - Grubb, T. D.

AU - Guarino, F.

AU - Guedes, G. P.

AU - Halliday, R.

AU - Hampel, M. R.

AU - Hansen, P.

AU - Harari, D.

AU - Harrison, T. A.

AU - Haungs, A.

AU - Hebbeker, T.

AU - Heck, D.

AU - Heimann, P.

AU - Herve, A. E.

AU - Hill, G. C.

AU - Hojvat, C.

AU - Holt, E.

AU - Homola, P.

AU - Hörandel, J. R.

AU - Horvath, P.

AU - Hrabovský, M.

AU - Huege, T.

AU - Hulsman, J.

AU - Insolia, A.

AU - Isar, P. G.

AU - Jandt, I.

AU - Johnsen, J. A.

AU - Josebachuili, M.

AU - Jurysek, J.

AU - Kääpä, A.

AU - Kambeitz, O.

AU - Kampert, K. H.

AU - Keilhauer, B.

AU - Kemmerich, N.

AU - Kemp, E.

AU - Kemp, J.

AU - Kieckhafer, R. M.

AU - Klages, H. O.

AU - Kleifges, M.

AU - Kleinfeller, J.

AU - Krause, R.

AU - Krohm, N.

AU - Kuempel, D.

AU - Kukec Mezek, G.

AU - Kunka, N.

AU - Kuotb Awad, A.

AU - Lago, B. L.

AU - Lahurd, D.

AU - Lang, R. G.

AU - Lauscher, M.

AU - Legumina, R.

AU - Leigui De Oliveira, M. A.

AU - Letessier-Selvon, A.

AU - Lhenry-Yvon, I.

AU - Link, K.

AU - Lo Presti, D.

AU - Lopes, L.

AU - López, R.

AU - López Casado, A.

AU - Lorek, R.

AU - Luce, Q.

AU - Lucero, A.

AU - Malacari, M.

AU - Mallamaci, M.

AU - Mandat, D.

AU - Mantsch, P.

AU - Mariazzi, A. G.

AU - Mariş, I. C.

AU - Marsella, G.

AU - Martello, D.

AU - Martinez, H.

AU - Martínez Bravo, O.

AU - Masías Meza, J. J.

AU - Mathes, H. J.

AU - Mathys, S.

AU - Matthews, J.

AU - Matthiae, G.

AU - Mayotte, E.

AU - Mazur, P. O.

AU - Medina, C.

AU - Medina-Tanco, G.

AU - Melo, D.

AU - Menshikov, A.

AU - Merenda, K. D.

AU - Michal, S.

AU - Micheletti, M. I.

AU - Middendorf, L.

AU - Miramonti, L.

AU - Mitrica, B.

AU - Mockler, D.

AU - Mollerach, S.

AU - Montanet, F.

AU - Morello, C.

AU - Morlino, G.

AU - Mostafá, M.

AU - Müller, A. L.

AU - Müller, G.

AU - Muller, M. A.

AU - Müller, S.

AU - Mussa, R.

AU - Naranjo, I.

AU - Nellen, L.

AU - Nguyen, P. H.

AU - Niculescu-Oglinzanu, M.

AU - Niechciol, M.

AU - Niemietz, L.

AU - Niggemann, T.

AU - Nitz, D.

AU - Nosek, D.

AU - Novotny, V.

AU - Nožka, L.

AU - Núñez, L. A.

AU - Oikonomou, F.

AU - Olinto, A.

AU - Palatka, M.

AU - Pallotta, J.

AU - Papenbreer, P.

AU - Parente, G.

AU - Parra, A.

AU - Paul, T.

AU - Pech, M.

AU - Pedreira, F.

AU - Pkala, J.

AU - Pelayo, R.

AU - Peña-Rodriguez, J.

AU - Pereira, L. A.S.

AU - Perlin, M.

AU - Perrone, L.

AU - Peters, C.

AU - Petrera, S.

AU - Phuntsok, J.

AU - Pierog, T.

AU - Pimenta, M.

AU - Pirronello, V.

AU - Platino, M.

AU - Plum, M.

AU - Poh, J.

AU - Porowski, C.

AU - Prado, R. R.

AU - Privitera, P.

AU - Prouza, M.

AU - Quel, E. J.

AU - Querchfeld, S.

AU - Quinn, S.

AU - Ramos-Pollan, R.

AU - Rautenberg, J.

AU - Ravignani, D.

AU - Ridky, J.

AU - Riehn, F.

AU - Risse, M.

AU - Ristori, P.

AU - Rizi, V.

AU - Rodrigues De Carvalho, W.

AU - Rodriguez Fernandez, G.

AU - Rodriguez Rojo, J.

AU - Roncoroni, M. J.

AU - Roth, M.

AU - Roulet, E.

AU - Rovero, A. C.

AU - Ruehl, P.

AU - Saffi, S. J.

AU - Saftoiu, A.

AU - Salamida, F.

AU - Salazar, H.

AU - Saleh, A.

AU - Salina, G.

AU - Sánchez, F.

AU - Sanchez-Lucas, P.

AU - Santos, E. M.

AU - Santos, E.

AU - Sarazin, F.

AU - Sarmento, R.

AU - Sarmiento-Cano, C.

AU - Sato, R.

AU - Schauer, M.

AU - Scherini, V.

AU - Schieler, H.

AU - Schimp, M.

AU - Schmidt, D.

AU - Scholten, O.

AU - Schovánek, P.

AU - Schröder, F. G.

AU - Schröder, S.

AU - Schulz, A.

AU - Schumacher, J.

AU - Sciutto, S. J.

AU - Segreto, A.

AU - Shadkam, A.

AU - Shellard, R. C.

AU - Sigl, G.

AU - Silli, G.

AU - Šmída, R.

AU - Snow, G. R.

AU - Sommers, P.

AU - Sonntag, S.

AU - Soriano, J. F.

AU - Squartini, R.

AU - Stanca, D.

AU - Stanič, S.

AU - Stasielak, J.

AU - Stassi, P.

AU - Stolpovskiy, M.

AU - Strafella, F.

AU - Streich, A.

AU - Suarez, F.

AU - Suarez Durán, M.

AU - Sudholz, T.

AU - Suomijärvi, T.

AU - Supanitsky, A. D.

AU - Šupík, J.

AU - Swain, J.

AU - Szadkowski, Z.

AU - Taboada, A.

AU - Taborda, O. A.

AU - Theodoro, V. M.

AU - Timmermans, C.

AU - Todero Peixoto, C. J.

AU - Tomankova, L.

AU - Tomé, B.

AU - Torralba Elipe, G.

AU - Travnicek, P.

AU - Trini, M.

AU - Ulrich, R.

AU - Unger, M.

AU - Urban, M.

AU - Valdés Galicia, J. F.

AU - Valiño, I.

AU - Valore, L.

AU - Van Aar, G.

AU - Van Bodegom, P.

AU - Van Den Berg, A. M.

AU - Van Vliet, A.

AU - Varela, E.

AU - Vargas Cárdenas, B.

AU - Vázquez, R. A.

AU - Veberič, D.

AU - Ventura, C.

AU - Vergara Quispe, I. D.

AU - Verzi, V.

AU - Vicha, J.

AU - Villaseñor, L.

AU - Vorobiov, S.

AU - Wahlberg, H.

AU - Wainberg, O.

AU - Walz, D.

AU - Watson, A. A.

AU - Weber, M.

AU - Weindl, A.

AU - Wiedeński, M.

AU - Wiencke, L.

AU - Wilczyński, H.

AU - Wirtz, M.

AU - Wittkowski, D.

AU - Wundheiler, B.

AU - Yang, L.

AU - Yushkov, A.

AU - Zas, E.

AU - Zavrtanik, D.

AU - Zavrtanik, M.

AU - Zepeda, A.

AU - Zimmermann, B.

AU - Ziolkowski, M.

AU - Zong, Z.

AU - Zuccarello, F.

PY - 2018/2/1

Y1 - 2018/2/1

N2 - A 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 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 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.

AB - A 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 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 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.

KW - astroparticle physics

KW - cosmic rays

KW - galaxies: active

KW - galaxies: starburst

KW - methods: data analysis Supporting material: FITS files

UR - http://www.scopus.com/inward/record.url?scp=85041621635&partnerID=8YFLogxK

UR - http://arxiv.org/abs/1801.06160 http://dx.doi.org/10.3847/2041-8213/aaa66d

UR - http://www.mendeley.com/research/indication-anisotropy-arrival-directions-ultrahighenergy-cosmic-rays-through-comparison-flux-pattern

U2 - 10.3847/2041-8213/aaa66d

DO - 10.3847/2041-8213/aaa66d

M3 - Article

VL - 853

JO - Astrophysical Journal Letters

JF - Astrophysical Journal Letters

SN - 2041-8205

IS - 2

M1 - L29

ER -