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Title: Measurement of the cosmic-ray energy spectrum above 2.5 × 10 18 eV using the Pierre Auger Observatory

Abstract

We report a measurement of the energy spectrum of cosmic rays for energies above $$2.5 {\times} 10^{18}~$$eV based on 215,030 events recorded with zenith angles below $$60^\circ$$. A key feature of the work is that the estimates of the energies are independent of assumptions about the unknown hadronic physics or of the primary mass composition. The measurement is the most precise made hitherto with the accumulated exposure being so large that the measurements of the flux are dominated by systematic uncertainties except at energies above $$5 {\times} 10^{19}~$$eV. The principal conclusions are: (1) The flattening of the spectrum near $$5 {\times} 10^{18}~$$eV, the so-called "ankle", is confirmed. (2) The steepening of the spectrum at around $$5 {\times} 10^{19}~$$eV is confirmed. (3) A new feature has been identified in the spectrum: in the region above the ankle the spectral index $$\gamma$$ of the particle flux ($$\propto E^{-\gamma}$$) changes from $$2.51 \pm 0.03~{\rm (stat.)} \pm 0.05~{\rm (sys.)}$$ to $$3.05 \pm 0.05~{\rm (stat.)} \pm 0.10~{\rm (sys.)}$$ before changing sharply to $$5.1 \pm 0.3~{\rm (stat.)} \pm 0.1~{\rm (sys.)}$$ above $$5 {\times} 10^{19}~$$eV. (4) No evidence for any dependence of the spectrum on declination has been found other than a mild excess from the Southern Hemisphere that is consistent with the anisotropy observed above $$8 {\times} 10^{18}~$$eV.

Authors:
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Publication Date:
Research Org.:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC), High Energy Physics (HEP); São Paulo Research Foundation (FAPESP); Czech Republic; Institut Lagrange de Paris (ILP); Consejo Nacional de Ciencia y Tecnología (CONACYT); Ministry of Science and Higher Education; National Science Centre; Romanian Ministry of Education and Research; Slovenian Research Agency; Ministerio de Economía, Industria y Competitividad; Xunta de Galicia; Junta de Andalucía; RENATA Red Nacional Temática de Astropartículas; María de Maeztu Unit of Excellence
Contributing Org.:
Pierre Auger Collaboration
OSTI Identifier:
1661742
Alternate Identifier(s):
OSTI ID: 1668400
Report Number(s):
arXiv:2008.06486; FERMILAB-PUB-20-432-E-TD
Journal ID: ISSN 2470-0010; PRVDAQ; 062005
Grant/Contract Number:  
AC02-07CH11359; FR02-04ER41300; FG02-99ER41107; SC0011689; 0450696; 2019/10151-2; 2010/07359-6; 1999/05404-3; MSMT CR LTT18004; LM2015038; LM2018102; CZ.02.1.01/0.0/0.0/16_013/0001402; CZ.02.1.01/0.0/0.0/18_046/0016010; CZ.02.1.01/0.0/0.0/17_049/0008422; LABEX ANR-10-LABX-63; ANR-11-IDEX-0004-02; 167733; DIR/WK/2018/11; 2013/08/M/ST9/00322; 2016/23/B/ST9/01635; HARMONIA 5–2013/10/M/ST9/00062; UMO-2016/22/M/ST9/00198; PN19150201/16N/2019; PN19060102; PN-III-P1-1.2-PCCDI-2017-0839/19PCCDI/2018; P1-0031; P1-0385; I0-0033; N1-0111; FPA2017-85114-P; FPA2017-85197-P; ED431C 2017/07; SOMM17/6104/UGR; FPA2015-68783-REDT; MDM-2016-0692
Resource Type:
Journal Article: Published Article
Journal Name:
Physical Review D
Additional Journal Information:
Journal Name: Physical Review D Journal Volume: 102 Journal Issue: 6; Journal ID: ISSN 2470-0010
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
79 ASTRONOMY AND ASTROPHYSICS

Citation Formats

Aab, A., Abreu, P., Aglietta, M., Albury, J. M., Allekotte, I., Almela, A., Alvarez Castillo, J., Alvarez-Muñiz, J., Alves Batista, R., Anastasi, G. A., Anchordoqui, L., Andrada, B., Andringa, S., Aramo, C., Araújo Ferreira, P. R., Asorey, H., Assis, P., Avila, G., Badescu, A. M., Bakalova, A., Balaceanu, A., Barbato, F., Barreira Luz, R. J., Becker, K. H., Bellido, J. A., Berat, C., Bertaina, M. E., Bertou, X., Biermann, P. L., Bister, T., Biteau, J., Blanco, A., Blazek, J., Bleve, C., Boháčová, M., Boncioli, D., Bonifazi, C., Bonneau Arbeletche, L., Borodai, N., Botti, A. M., Brack, J., Bretz, T., Briechle, F. L., Buchholz, P., Bueno, A., Buitink, S., Buscemi, M., Caballero-Mora, K. S., Caccianiga, L., Calcagni, L., Cancio, A., Canfora, F., Caracas, I., Carceller, J. M., Caruso, R., Castellina, A., Catalani, F., Cataldi, G., Cazon, L., Cerda, M., Chinellato, J. A., Choi, K., Chudoba, J., Chytka, L., Clay, R. W., Cobos Cerutti, A. C., Colalillo, R., Coleman, A., Coluccia, M. R., Conceição, R., Condorelli, A., Consolati, G., Contreras, F., Convenga, F., Covault, C. E., Dasso, S., Daumiller, K., Dawson, B. R., Day, J. A., de Almeida, R. M., de Jesús, J., de Jong, S. J., De Mauro, G., de Mello Neto, J. R. T., De Mitri, I., de Oliveira, J., de Oliveira Franco, D., de Souza, V., De Vito, E., Debatin, J., del Río, M., Deligny, O., Dembinski, H., Dhital, N., Di Giulio, C., Di Matteo, A., Díaz Castro, M. L., Dobrigkeit, C., D’Olivo, J. C., Dorosti, Q., dos Anjos, R. C., Dova, M. T., Ebr, J., Engel, R., Epicoco, I., Erdmann, M., Escobar, C. O., Etchegoyen, A., Falcke, H., Farmer, J., Farrar, G., Fauth, A. C., Fazzini, N., Feldbusch, F., Fenu, F., Fick, B., Figueira, J. M., Filipčič, A., Fodran, T., Freire, M. M., Fujii, T., Fuster, A., Galea, C., Galelli, C., García, B., Garcia Vegas, A. L., Gemmeke, H., Gesualdi, F., Gherghel-Lascu, A., Ghia, P. L., Giaccari, U., Giammarchi, M., Giller, M., Glombitza, J., Gobbi, F., Gollan, F., Golup, G., Gómez Berisso, M., Gómez Vitale, P. F., Gongora, J. P., González, N., Goos, I., Góra, D., Gorgi, A., Gottowik, M., Grubb, T. D., Guarino, F., Guedes, G. P., Guido, E., Hahn, S., Halliday, R., Hampel, M. R., Hansen, P., Harari, D., Harvey, V. M., Haungs, A., Hebbeker, T., Heck, D., Hill, G. C., Hojvat, C., Hörandel, J. R., Horvath, P., Hrabovský, M., Huege, T., Hulsman, J., Insolia, A., Isar, P. G., Johnsen, J. A., Jurysek, J., Kääpä, A., Kampert, K. H., Keilhauer, B., Kemp, J., Klages, H. O., Kleifges, M., Kleinfeller, J., Köpke, M., Kukec Mezek, G., Lago, B. L., LaHurd, D., Lang, R. G., Leigui de Oliveira, M. A., Lenok, V., Letessier-Selvon, A., Lhenry-Yvon, I., Lo Presti, D., Lopes, L., López, R., Lorek, R., Luce, Q., Lucero, A., Machado Payeras, A., Malacari, M., Mancarella, G., Mandat, D., Manning, B. C., Manshanden, J., Mantsch, P., Marafico, S., Mariazzi, A. G., Mariş, I. C., Marsella, G., Martello, D., Martinez, H., Martínez Bravo, O., Mastrodicasa, M., Mathes, H. J., Matthews, J., Matthiae, G., Mayotte, E., Mazur, P. O., Medina-Tanco, G., Melo, D., Menshikov, A., Merenda, K. -D., Michal, S., Micheletti, M. I., Miramonti, L., Mockler, D., Mollerach, S., Montanet, F., Morello, C., Mostafá, M., Müller, A. L., Muller, M. A., Mulrey, K., Mussa, R., Muzio, M., Namasaka, W. M., Nellen, L., Nguyen, P. H., Niculescu-Oglinzanu, M., Niechciol, M., Nitz, D., Nosek, D., Novotny, V., Nožka, L., Nucita, A., Núñez, L. A., Palatka, M., Pallotta, J., Panetta, M. P., Papenbreer, P., Parente, G., Parra, A., Pech, M., Pedreira, F., Pȩkala, J., Pelayo, R., Peña-Rodriguez, J., Perez Armand, J., Perlin, M., Perrone, L., Peters, C., Petrera, S., Pierog, T., Pimenta, M., Pirronello, V., Platino, M., Pont, B., Pothast, M., Privitera, P., Prouza, M., Puyleart, A., Querchfeld, S., Rautenberg, J., Ravignani, D., Reininghaus, M., 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., Salina, G., Sanabria Gomez, J. D., Sánchez, F., Santos, E. M., Santos, E., Sarazin, F., Sarmento, R., Sarmiento-Cano, C., Sato, R., Savina, P., Schäfer, C., Scherini, V., Schieler, H., Schimassek, M., Schimp, M., Schlüter, F., Schmidt, D., Scholten, O., Schovánek, P., Schröder, F. G., Schröder, S., Schulz, A., Sciutto, S. J., Scornavacche, M., Shellard, R. C., Sigl, G., Silli, G., Sima, O., Šmída, R., Sommers, P., Soriano, J. F., Souchard, J., Squartini, R., Stadelmaier, M., Stanca, D., Stanič, S., Stasielak, J., Stassi, P., Streich, A., Suárez-Durán, M., Sudholz, T., Suomijärvi, T., Supanitsky, A. D., Šupík, J., Szadkowski, Z., Taboada, A., Tapia, A., Timmermans, C., Tkachenko, O., Tobiska, P., Todero Peixoto, C. J., Tomé, B., Torralba Elipe, G., Travaini, A., Travnicek, P., Trimarelli, C., Trini, M., Tueros, M., Ulrich, R., Unger, M., Urban, M., Vaclavek, L., Vacula, M., Valdés Galicia, J. F., Valiño, I., Valore, L., van Vliet, A., Varela, E., Vargas Cárdenas, B., Vásquez-Ramírez, A., Veberič, D., Ventura, C., Vergara Quispe, I. D., Verzi, V., Vicha, J., Villaseñor, L., Vink, J., Vorobiov, S., Wahlberg, H., Watson, A. A., Weber, M., Weindl, A., Wiencke, L., Wilczyński, H., Winchen, T., Wirtz, M., Wittkowski, D., Wundheiler, B., Yushkov, A., Zapparrata, O., Zas, E., Zavrtanik, D., Zavrtanik, M., Zehrer, L., Zepeda, A., Ziolkowski, M., Zuccarello, F., and The Pierre Auger Collaboration. Measurement of the cosmic-ray energy spectrum above 2.5 × 10 18     eV using the Pierre Auger Observatory. United States: N. p., 2020. Web. doi:10.1103/PhysRevD.102.062005.
Aab, A., Abreu, P., Aglietta, M., Albury, J. M., Allekotte, I., Almela, A., Alvarez Castillo, J., Alvarez-Muñiz, J., Alves Batista, R., Anastasi, G. A., Anchordoqui, L., Andrada, B., Andringa, S., Aramo, C., Araújo Ferreira, P. R., Asorey, H., Assis, P., Avila, G., Badescu, A. M., Bakalova, A., Balaceanu, A., Barbato, F., Barreira Luz, R. J., Becker, K. H., Bellido, J. A., Berat, C., Bertaina, M. E., Bertou, X., Biermann, P. L., Bister, T., Biteau, J., Blanco, A., Blazek, J., Bleve, C., Boháčová, M., Boncioli, D., Bonifazi, C., Bonneau Arbeletche, L., Borodai, N., Botti, A. M., Brack, J., Bretz, T., Briechle, F. L., Buchholz, P., Bueno, A., Buitink, S., Buscemi, M., Caballero-Mora, K. S., Caccianiga, L., Calcagni, L., Cancio, A., Canfora, F., Caracas, I., Carceller, J. M., Caruso, R., Castellina, A., Catalani, F., Cataldi, G., Cazon, L., Cerda, M., Chinellato, J. A., Choi, K., Chudoba, J., Chytka, L., Clay, R. W., Cobos Cerutti, A. C., Colalillo, R., Coleman, A., Coluccia, M. R., Conceição, R., Condorelli, A., Consolati, G., Contreras, F., Convenga, F., Covault, C. E., Dasso, S., Daumiller, K., Dawson, B. R., Day, J. A., de Almeida, R. M., de Jesús, J., de Jong, S. J., De Mauro, G., de Mello Neto, J. R. T., De Mitri, I., de Oliveira, J., de Oliveira Franco, D., de Souza, V., De Vito, E., Debatin, J., del Río, M., Deligny, O., Dembinski, H., Dhital, N., Di Giulio, C., Di Matteo, A., Díaz Castro, M. L., Dobrigkeit, C., D’Olivo, J. C., Dorosti, Q., dos Anjos, R. C., Dova, M. T., Ebr, J., Engel, R., Epicoco, I., Erdmann, M., Escobar, C. O., Etchegoyen, A., Falcke, H., Farmer, J., Farrar, G., Fauth, A. C., Fazzini, N., Feldbusch, F., Fenu, F., Fick, B., Figueira, J. M., Filipčič, A., Fodran, T., Freire, M. M., Fujii, T., Fuster, A., Galea, C., Galelli, C., García, B., Garcia Vegas, A. L., Gemmeke, H., Gesualdi, F., Gherghel-Lascu, A., Ghia, P. L., Giaccari, U., Giammarchi, M., Giller, M., Glombitza, J., Gobbi, F., Gollan, F., Golup, G., Gómez Berisso, M., Gómez Vitale, P. F., Gongora, J. P., González, N., Goos, I., Góra, D., Gorgi, A., Gottowik, M., Grubb, T. D., Guarino, F., Guedes, G. P., Guido, E., Hahn, S., Halliday, R., Hampel, M. R., Hansen, P., Harari, D., Harvey, V. M., Haungs, A., Hebbeker, T., Heck, D., Hill, G. C., Hojvat, C., Hörandel, J. R., Horvath, P., Hrabovský, M., Huege, T., Hulsman, J., Insolia, A., Isar, P. G., Johnsen, J. A., Jurysek, J., Kääpä, A., Kampert, K. H., Keilhauer, B., Kemp, J., Klages, H. O., Kleifges, M., Kleinfeller, J., Köpke, M., Kukec Mezek, G., Lago, B. L., LaHurd, D., Lang, R. G., Leigui de Oliveira, M. A., Lenok, V., Letessier-Selvon, A., Lhenry-Yvon, I., Lo Presti, D., Lopes, L., López, R., Lorek, R., Luce, Q., Lucero, A., Machado Payeras, A., Malacari, M., Mancarella, G., Mandat, D., Manning, B. C., Manshanden, J., Mantsch, P., Marafico, S., Mariazzi, A. G., Mariş, I. C., Marsella, G., Martello, D., Martinez, H., Martínez Bravo, O., Mastrodicasa, M., Mathes, H. J., Matthews, J., Matthiae, G., Mayotte, E., Mazur, P. O., Medina-Tanco, G., Melo, D., Menshikov, A., Merenda, K. -D., Michal, S., Micheletti, M. I., Miramonti, L., Mockler, D., Mollerach, S., Montanet, F., Morello, C., Mostafá, M., Müller, A. L., Muller, M. A., Mulrey, K., Mussa, R., Muzio, M., Namasaka, W. M., Nellen, L., Nguyen, P. H., Niculescu-Oglinzanu, M., Niechciol, M., Nitz, D., Nosek, D., Novotny, V., Nožka, L., Nucita, A., Núñez, L. A., Palatka, M., Pallotta, J., Panetta, M. P., Papenbreer, P., Parente, G., Parra, A., Pech, M., Pedreira, F., Pȩkala, J., Pelayo, R., Peña-Rodriguez, J., Perez Armand, J., Perlin, M., Perrone, L., Peters, C., Petrera, S., Pierog, T., Pimenta, M., Pirronello, V., Platino, M., Pont, B., Pothast, M., Privitera, P., Prouza, M., Puyleart, A., Querchfeld, S., Rautenberg, J., Ravignani, D., Reininghaus, M., 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., Salina, G., Sanabria Gomez, J. D., Sánchez, F., Santos, E. M., Santos, E., Sarazin, F., Sarmento, R., Sarmiento-Cano, C., Sato, R., Savina, P., Schäfer, C., Scherini, V., Schieler, H., Schimassek, M., Schimp, M., Schlüter, F., Schmidt, D., Scholten, O., Schovánek, P., Schröder, F. G., Schröder, S., Schulz, A., Sciutto, S. J., Scornavacche, M., Shellard, R. C., Sigl, G., Silli, G., Sima, O., Šmída, R., Sommers, P., Soriano, J. F., Souchard, J., Squartini, R., Stadelmaier, M., Stanca, D., Stanič, S., Stasielak, J., Stassi, P., Streich, A., Suárez-Durán, M., Sudholz, T., Suomijärvi, T., Supanitsky, A. D., Šupík, J., Szadkowski, Z., Taboada, A., Tapia, A., Timmermans, C., Tkachenko, O., Tobiska, P., Todero Peixoto, C. J., Tomé, B., Torralba Elipe, G., Travaini, A., Travnicek, P., Trimarelli, C., Trini, M., Tueros, M., Ulrich, R., Unger, M., Urban, M., Vaclavek, L., Vacula, M., Valdés Galicia, J. F., Valiño, I., Valore, L., van Vliet, A., Varela, E., Vargas Cárdenas, B., Vásquez-Ramírez, A., Veberič, D., Ventura, C., Vergara Quispe, I. D., Verzi, V., Vicha, J., Villaseñor, L., Vink, J., Vorobiov, S., Wahlberg, H., Watson, A. A., Weber, M., Weindl, A., Wiencke, L., Wilczyński, H., Winchen, T., Wirtz, M., Wittkowski, D., Wundheiler, B., Yushkov, A., Zapparrata, O., Zas, E., Zavrtanik, D., Zavrtanik, M., Zehrer, L., Zepeda, A., Ziolkowski, M., Zuccarello, F., & The Pierre Auger Collaboration. Measurement of the cosmic-ray energy spectrum above 2.5 × 10 18     eV using the Pierre Auger Observatory. United States. doi:10.1103/PhysRevD.102.062005.
Aab, A., Abreu, P., Aglietta, M., Albury, J. M., Allekotte, I., Almela, A., Alvarez Castillo, J., Alvarez-Muñiz, J., Alves Batista, R., Anastasi, G. A., Anchordoqui, L., Andrada, B., Andringa, S., Aramo, C., Araújo Ferreira, P. R., Asorey, H., Assis, P., Avila, G., Badescu, A. M., Bakalova, A., Balaceanu, A., Barbato, F., Barreira Luz, R. J., Becker, K. H., Bellido, J. A., Berat, C., Bertaina, M. E., Bertou, X., Biermann, P. L., Bister, T., Biteau, J., Blanco, A., Blazek, J., Bleve, C., Boháčová, M., Boncioli, D., Bonifazi, C., Bonneau Arbeletche, L., Borodai, N., Botti, A. M., Brack, J., Bretz, T., Briechle, F. L., Buchholz, P., Bueno, A., Buitink, S., Buscemi, M., Caballero-Mora, K. S., Caccianiga, L., Calcagni, L., Cancio, A., Canfora, F., Caracas, I., Carceller, J. M., Caruso, R., Castellina, A., Catalani, F., Cataldi, G., Cazon, L., Cerda, M., Chinellato, J. A., Choi, K., Chudoba, J., Chytka, L., Clay, R. W., Cobos Cerutti, A. C., Colalillo, R., Coleman, A., Coluccia, M. R., Conceição, R., Condorelli, A., Consolati, G., Contreras, F., Convenga, F., Covault, C. E., Dasso, S., Daumiller, K., Dawson, B. R., Day, J. A., de Almeida, R. M., de Jesús, J., de Jong, S. J., De Mauro, G., de Mello Neto, J. R. T., De Mitri, I., de Oliveira, J., de Oliveira Franco, D., de Souza, V., De Vito, E., Debatin, J., del Río, M., Deligny, O., Dembinski, H., Dhital, N., Di Giulio, C., Di Matteo, A., Díaz Castro, M. L., Dobrigkeit, C., D’Olivo, J. C., Dorosti, Q., dos Anjos, R. C., Dova, M. T., Ebr, J., Engel, R., Epicoco, I., Erdmann, M., Escobar, C. O., Etchegoyen, A., Falcke, H., Farmer, J., Farrar, G., Fauth, A. C., Fazzini, N., Feldbusch, F., Fenu, F., Fick, B., Figueira, J. M., Filipčič, A., Fodran, T., Freire, M. M., Fujii, T., Fuster, A., Galea, C., Galelli, C., García, B., Garcia Vegas, A. L., Gemmeke, H., Gesualdi, F., Gherghel-Lascu, A., Ghia, P. L., Giaccari, U., Giammarchi, M., Giller, M., Glombitza, J., Gobbi, F., Gollan, F., Golup, G., Gómez Berisso, M., Gómez Vitale, P. F., Gongora, J. P., González, N., Goos, I., Góra, D., Gorgi, A., Gottowik, M., Grubb, T. D., Guarino, F., Guedes, G. P., Guido, E., Hahn, S., Halliday, R., Hampel, M. R., Hansen, P., Harari, D., Harvey, V. M., Haungs, A., Hebbeker, T., Heck, D., Hill, G. C., Hojvat, C., Hörandel, J. R., Horvath, P., Hrabovský, M., Huege, T., Hulsman, J., Insolia, A., Isar, P. G., Johnsen, J. A., Jurysek, J., Kääpä, A., Kampert, K. H., Keilhauer, B., Kemp, J., Klages, H. O., Kleifges, M., Kleinfeller, J., Köpke, M., Kukec Mezek, G., Lago, B. L., LaHurd, D., Lang, R. G., Leigui de Oliveira, M. A., Lenok, V., Letessier-Selvon, A., Lhenry-Yvon, I., Lo Presti, D., Lopes, L., López, R., Lorek, R., Luce, Q., Lucero, A., Machado Payeras, A., Malacari, M., Mancarella, G., Mandat, D., Manning, B. C., Manshanden, J., Mantsch, P., Marafico, S., Mariazzi, A. G., Mariş, I. C., Marsella, G., Martello, D., Martinez, H., Martínez Bravo, O., Mastrodicasa, M., Mathes, H. J., Matthews, J., Matthiae, G., Mayotte, E., Mazur, P. O., Medina-Tanco, G., Melo, D., Menshikov, A., Merenda, K. -D., Michal, S., Micheletti, M. I., Miramonti, L., Mockler, D., Mollerach, S., Montanet, F., Morello, C., Mostafá, M., Müller, A. L., Muller, M. A., Mulrey, K., Mussa, R., Muzio, M., Namasaka, W. M., Nellen, L., Nguyen, P. H., Niculescu-Oglinzanu, M., Niechciol, M., Nitz, D., Nosek, D., Novotny, V., Nožka, L., Nucita, A., Núñez, L. A., Palatka, M., Pallotta, J., Panetta, M. P., Papenbreer, P., Parente, G., Parra, A., Pech, M., Pedreira, F., Pȩkala, J., Pelayo, R., Peña-Rodriguez, J., Perez Armand, J., Perlin, M., Perrone, L., Peters, C., Petrera, S., Pierog, T., Pimenta, M., Pirronello, V., Platino, M., Pont, B., Pothast, M., Privitera, P., Prouza, M., Puyleart, A., Querchfeld, S., Rautenberg, J., Ravignani, D., Reininghaus, M., 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., Salina, G., Sanabria Gomez, J. D., Sánchez, F., Santos, E. M., Santos, E., Sarazin, F., Sarmento, R., Sarmiento-Cano, C., Sato, R., Savina, P., Schäfer, C., Scherini, V., Schieler, H., Schimassek, M., Schimp, M., Schlüter, F., Schmidt, D., Scholten, O., Schovánek, P., Schröder, F. G., Schröder, S., Schulz, A., Sciutto, S. J., Scornavacche, M., Shellard, R. C., Sigl, G., Silli, G., Sima, O., Šmída, R., Sommers, P., Soriano, J. F., Souchard, J., Squartini, R., Stadelmaier, M., Stanca, D., Stanič, S., Stasielak, J., Stassi, P., Streich, A., Suárez-Durán, M., Sudholz, T., Suomijärvi, T., Supanitsky, A. D., Šupík, J., Szadkowski, Z., Taboada, A., Tapia, A., Timmermans, C., Tkachenko, O., Tobiska, P., Todero Peixoto, C. J., Tomé, B., Torralba Elipe, G., Travaini, A., Travnicek, P., Trimarelli, C., Trini, M., Tueros, M., Ulrich, R., Unger, M., Urban, M., Vaclavek, L., Vacula, M., Valdés Galicia, J. F., Valiño, I., Valore, L., van Vliet, A., Varela, E., Vargas Cárdenas, B., Vásquez-Ramírez, A., Veberič, D., Ventura, C., Vergara Quispe, I. D., Verzi, V., Vicha, J., Villaseñor, L., Vink, J., Vorobiov, S., Wahlberg, H., Watson, A. A., Weber, M., Weindl, A., Wiencke, L., Wilczyński, H., Winchen, T., Wirtz, M., Wittkowski, D., Wundheiler, B., Yushkov, A., Zapparrata, O., Zas, E., Zavrtanik, D., Zavrtanik, M., Zehrer, L., Zepeda, A., Ziolkowski, M., Zuccarello, F., and The Pierre Auger Collaboration. Wed . "Measurement of the cosmic-ray energy spectrum above 2.5 × 10 18     eV using the Pierre Auger Observatory". United States. doi:10.1103/PhysRevD.102.062005.
@article{osti_1661742,
title = {Measurement of the cosmic-ray energy spectrum above 2.5 × 10 18     eV using the Pierre Auger Observatory},
author = {Aab, A. and Abreu, P. and Aglietta, M. and Albury, J. M. and Allekotte, I. and Almela, A. and Alvarez Castillo, J. and Alvarez-Muñiz, J. and Alves Batista, R. and Anastasi, G. A. and Anchordoqui, L. and Andrada, B. and Andringa, S. and Aramo, C. and Araújo Ferreira, P. R. and Asorey, H. and Assis, P. and Avila, G. and Badescu, A. M. and Bakalova, A. and Balaceanu, A. and Barbato, F. and Barreira Luz, R. J. and Becker, K. H. and Bellido, J. A. and Berat, C. and Bertaina, M. E. and Bertou, X. and Biermann, P. L. and Bister, T. and Biteau, J. and Blanco, A. and Blazek, J. and Bleve, C. and Boháčová, M. and Boncioli, D. and Bonifazi, C. and Bonneau Arbeletche, L. and Borodai, N. and Botti, A. M. and Brack, J. and Bretz, T. and Briechle, F. L. and Buchholz, P. and Bueno, A. and Buitink, S. and Buscemi, M. and Caballero-Mora, K. S. and Caccianiga, L. and Calcagni, L. and Cancio, A. and Canfora, F. and Caracas, I. and Carceller, J. M. and Caruso, R. and Castellina, A. and Catalani, F. and Cataldi, G. and Cazon, L. and Cerda, M. and Chinellato, J. A. and Choi, K. and Chudoba, J. and Chytka, L. and Clay, R. W. and Cobos Cerutti, A. C. and Colalillo, R. and Coleman, A. and Coluccia, M. R. and Conceição, R. and Condorelli, A. and Consolati, G. and Contreras, F. and Convenga, F. and Covault, C. E. and Dasso, S. and Daumiller, K. and Dawson, B. R. and Day, J. A. and de Almeida, R. M. and de Jesús, J. 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 Oliveira Franco, D. and de Souza, V. and De Vito, E. and Debatin, J. and del Río, M. and Deligny, O. and Dembinski, H. and Dhital, N. and Di Giulio, C. and Di Matteo, A. and Díaz Castro, M. L. and Dobrigkeit, C. and D’Olivo, J. C. and Dorosti, Q. and dos Anjos, R. C. and Dova, M. T. and Ebr, J. and Engel, R. and Epicoco, I. and Erdmann, M. and Escobar, C. O. and Etchegoyen, A. and Falcke, H. and Farmer, J. and Farrar, G. and Fauth, A. C. and Fazzini, N. and Feldbusch, F. and Fenu, F. and Fick, B. and Figueira, J. M. and Filipčič, A. and Fodran, T. and Freire, M. M. and Fujii, T. and Fuster, A. and Galea, C. and Galelli, C. and García, B. and Garcia Vegas, A. L. and Gemmeke, H. and Gesualdi, F. and Gherghel-Lascu, A. and Ghia, P. L. and Giaccari, U. and Giammarchi, M. and Giller, M. and Glombitza, J. and Gobbi, F. and Gollan, F. and Golup, G. and Gómez Berisso, M. and Gómez Vitale, P. F. and Gongora, J. P. and González, N. and Goos, I. and Góra, D. and Gorgi, A. and Gottowik, M. and Grubb, T. D. and Guarino, F. and Guedes, G. P. and Guido, E. and Hahn, S. and Halliday, R. and Hampel, M. R. and Hansen, P. and Harari, D. and Harvey, V. M. and Haungs, A. and Hebbeker, T. and Heck, D. and Hill, G. C. and Hojvat, C. and Hörandel, J. R. and Horvath, P. and Hrabovský, M. and Huege, T. and Hulsman, J. and Insolia, A. and Isar, P. G. and Johnsen, J. A. and Jurysek, J. and Kääpä, A. and Kampert, K. H. and Keilhauer, B. and Kemp, J. and Klages, H. O. and Kleifges, M. and Kleinfeller, J. and Köpke, M. and Kukec Mezek, G. and Lago, B. L. and LaHurd, D. and Lang, R. G. and Leigui de Oliveira, M. A. and Lenok, V. and Letessier-Selvon, A. and Lhenry-Yvon, I. and Lo Presti, D. and Lopes, L. and López, R. and Lorek, R. and Luce, Q. and Lucero, A. and Machado Payeras, A. and Malacari, M. and Mancarella, G. and Mandat, D. and Manning, B. C. and Manshanden, J. and Mantsch, P. and Marafico, S. and Mariazzi, A. G. and Mariş, I. C. and Marsella, G. and Martello, D. and Martinez, H. and Martínez Bravo, O. and Mastrodicasa, M. and Mathes, H. J. and Matthews, J. and Matthiae, G. and Mayotte, E. and Mazur, P. O. and Medina-Tanco, G. and Melo, D. and Menshikov, A. and Merenda, K. -D. and Michal, S. and Micheletti, M. I. and Miramonti, L. and Mockler, D. and Mollerach, S. and Montanet, F. and Morello, C. and Mostafá, M. and Müller, A. L. and Muller, M. A. and Mulrey, K. and Mussa, R. and Muzio, M. and Namasaka, W. M. and Nellen, L. and Nguyen, P. H. and Niculescu-Oglinzanu, M. and Niechciol, M. and Nitz, D. and Nosek, D. and Novotny, V. and Nožka, L. and Nucita, A. and Núñez, L. A. and Palatka, M. and Pallotta, J. and Panetta, M. P. and Papenbreer, P. and Parente, G. and Parra, A. and Pech, M. and Pedreira, F. and Pȩkala, J. and Pelayo, R. and Peña-Rodriguez, J. and Perez Armand, J. and Perlin, M. and Perrone, L. and Peters, C. and Petrera, S. and Pierog, T. and Pimenta, M. and Pirronello, V. and Platino, M. and Pont, B. and Pothast, M. and Privitera, P. and Prouza, M. and Puyleart, A. and Querchfeld, S. and Rautenberg, J. and Ravignani, D. and Reininghaus, M. and Ridky, J. and Riehn, F. and Risse, M. and Ristori, P. and Rizi, V. and Rodrigues de Carvalho, W. and Rodriguez Fernandez, G. and Rodriguez Rojo, J. and Roncoroni, M. J. and Roth, M. and Roulet, E. and Rovero, A. C. and Ruehl, P. and Saffi, S. J. and Saftoiu, A. and Salamida, F. and Salazar, H. and Salina, G. and Sanabria Gomez, J. D. and Sánchez, F. and Santos, E. M. and Santos, E. and Sarazin, F. and Sarmento, R. and Sarmiento-Cano, C. and Sato, R. and Savina, P. and Schäfer, C. and Scherini, V. and Schieler, H. and Schimassek, M. and Schimp, M. and Schlüter, F. and Schmidt, D. and Scholten, O. and Schovánek, P. and Schröder, F. G. and Schröder, S. and Schulz, A. and Sciutto, S. J. and Scornavacche, M. and Shellard, R. C. and Sigl, G. and Silli, G. and Sima, O. and Šmída, R. and Sommers, P. and Soriano, J. F. and Souchard, J. and Squartini, R. and Stadelmaier, M. and Stanca, D. and Stanič, S. and Stasielak, J. and Stassi, P. and Streich, A. and Suárez-Durán, M. and Sudholz, T. and Suomijärvi, T. and Supanitsky, A. D. and Šupík, J. and Szadkowski, Z. and Taboada, A. and Tapia, A. and Timmermans, C. and Tkachenko, O. and Tobiska, P. and Todero Peixoto, C. J. and Tomé, B. and Torralba Elipe, G. and Travaini, A. and Travnicek, P. and Trimarelli, C. and Trini, M. and Tueros, M. and Ulrich, R. and Unger, M. and Urban, M. and Vaclavek, L. and Vacula, M. and Valdés Galicia, J. F. and Valiño, I. and Valore, L. and van Vliet, A. and Varela, E. and Vargas Cárdenas, B. and Vásquez-Ramírez, A. and Veberič, D. and Ventura, C. and Vergara Quispe, I. D. and Verzi, V. and Vicha, J. and Villaseñor, L. and Vink, J. and Vorobiov, S. and Wahlberg, H. and Watson, A. A. and Weber, M. and Weindl, A. and Wiencke, L. and Wilczyński, H. and Winchen, T. and Wirtz, M. and Wittkowski, D. and Wundheiler, B. and Yushkov, A. and Zapparrata, O. and Zas, E. and Zavrtanik, D. and Zavrtanik, M. and Zehrer, L. and Zepeda, A. and Ziolkowski, M. and Zuccarello, F. and The Pierre Auger Collaboration},
abstractNote = {We report a measurement of the energy spectrum of cosmic rays for energies above $2.5 {\times} 10^{18}~$eV based on 215,030 events recorded with zenith angles below $60^\circ$. A key feature of the work is that the estimates of the energies are independent of assumptions about the unknown hadronic physics or of the primary mass composition. The measurement is the most precise made hitherto with the accumulated exposure being so large that the measurements of the flux are dominated by systematic uncertainties except at energies above $5 {\times} 10^{19}~$eV. The principal conclusions are: (1) The flattening of the spectrum near $5 {\times} 10^{18}~$eV, the so-called "ankle", is confirmed. (2) The steepening of the spectrum at around $5 {\times} 10^{19}~$eV is confirmed. (3) A new feature has been identified in the spectrum: in the region above the ankle the spectral index $\gamma$ of the particle flux ($\propto E^{-\gamma}$) changes from $2.51 \pm 0.03~{\rm (stat.)} \pm 0.05~{\rm (sys.)}$ to $3.05 \pm 0.05~{\rm (stat.)} \pm 0.10~{\rm (sys.)}$ before changing sharply to $5.1 \pm 0.3~{\rm (stat.)} \pm 0.1~{\rm (sys.)}$ above $5 {\times} 10^{19}~$eV. (4) No evidence for any dependence of the spectrum on declination has been found other than a mild excess from the Southern Hemisphere that is consistent with the anisotropy observed above $8 {\times} 10^{18}~$eV.},
doi = {10.1103/PhysRevD.102.062005},
journal = {Physical Review D},
issn = {2470-0010},
number = 6,
volume = 102,
place = {United States},
year = {2020},
month = {9}
}

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Works referenced in this record:

Spectral features in the cosmic ray fluxes
journal, January 2018


Features of the Energy Spectrum of Cosmic Rays above 2.5 × 10 18 eV Using the Pierre Auger Observatory
journal, September 2020


Normalization of the extragalactic background light from high-energy γ -ray observations
journal, July 2019


The Energy Spectrum of Cosmic Rays at the Highest Energies
conference, January 2018

  • AbuZayyad, Tareq; Deligny, Olivier; Ikeda, Daisuke
  • Proceedings of 2016 International Conference on Ultra-High Energy Cosmic Rays (UHECR2016)
  • DOI: 10.7566/JPSCP.19.011003

The effect of the geomagnetic field on cosmic ray energy estimates and large scale anisotropy searches on data from the Pierre Auger Observatory
journal, November 2011


Data-driven estimation of the invisible energy of cosmic ray showers with the Pierre Auger Observatory
journal, October 2019


Temperature and humidity dependence of air fluorescence yield measured by AIRFLY
journal, November 2008

  • Ave, M.; Bohacova, M.; Buonomo, B.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 597, Issue 1
  • DOI: 10.1016/j.nima.2008.08.050

Combined fit of spectrum and composition data as measured by the Pierre Auger Observatory
journal, April 2017


The optimum distance at which to determine the size of a giant air shower
journal, January 2007


Precise measurement of the absolute fluorescence yield of the 337nm band in atmospheric gases
journal, February 2013


A likelihood method to cross-calibrate air-shower detectors
journal, January 2016


Observations of Extensive Air Showers near the Maximum of Their Longitudinal Development
journal, January 1961


Extremely Energetic Cosmic-Ray Event
journal, May 1961


Measurement of energy spectrum of ultra-high energy cosmic rays
journal, November 2017

  • Verzi, Valerio; Ivanov, Dmitri; Tsunesada, Yoshiki
  • Progress of Theoretical and Experimental Physics, Vol. 2017, Issue 12
  • DOI: 10.1093/ptep/ptx082

Large-scale Cosmic-Ray Anisotropies above 4 EeV Measured by the Pierre Auger Observatory
journal, November 2018


The exposure of the hybrid detector of the Pierre Auger Observatory
journal, January 2011


On astrophysical solution to ultrahigh energy cosmic rays
journal, August 2006


Ultrahigh energy cosmic rays
journal, September 2011


Evidence for a Primary Cosmic-Ray Particle with Energy 10 20 eV
journal, February 1963


Reconstruction of inclined air showers detected with the Pierre Auger Observatory
journal, August 2014


The fluorescence detector of the Pierre Auger Observatory
journal, August 2010

  • Abraham, J.; Abreu, P.; Aglietta, M.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 620, Issue 2-3
  • DOI: 10.1016/j.nima.2010.04.023

Cosmic ray anisotropy analysis with a full-sky observatory
journal, January 2001


The Cosmic-Ray Energy Spectrum Observed with the Surface Detector of the Telescope Array Experiment
journal, April 2013


Observation of a large-scale anisotropy in the arrival directions of cosmic rays above 8 × 10 18 eV
journal, September 2017


Measurement of the pressure dependence of air fluorescence emission induced by electrons
journal, September 2007


High-energy cosmic rays and the Greisen–Zatsepin–Kuz'min effect
journal, February 2014


Cosmic rays from the ankle to the cutoff
journal, April 2014


Trigger and aperture of the surface detector array of the Pierre Auger Observatory
journal, January 2010

  • Abraham, J.; Abreu, P.; Aglietta, M.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 613, Issue 1
  • DOI: 10.1016/j.nima.2009.11.018

Auger-TA energy spectrum working group report
journal, January 2019


First Observation of the Greisen-Zatsepin-Kuzmin Suppression
journal, March 2008


Description of atmospheric conditions at the Pierre Auger Observatory using the Global Data Assimilation System (GDAS)
journal, April 2012


Clarification of the use of CHI-square and likelihood functions in fits to histograms
journal, April 1984


Unified approach to the classical statistical analysis of small signals
journal, April 1998


Observation of the Suppression of the Flux of Cosmic Rays above 4 × 10 19 eV
journal, August 2008


Past, present, and future of UHECR observations
journal, November 2017

  • Dawson, B. R.; Fukushima, M.; Sokolsky, P.
  • Progress of Theoretical and Experimental Physics, Vol. 2017, Issue 12
  • DOI: 10.1093/ptep/ptx054

Depth of maximum of air-shower profiles at the Pierre Auger Observatory. II. Composition implications
journal, December 2014


Measurement of Light Emission from Remote Cosmic-Ray Air Showers
journal, September 1977


Measurement of the average shape of longitudinal profiles of cosmic-ray air showers at the Pierre Auger Observatory
journal, March 2019


Reconstruction of longitudinal profiles of ultra-high energy cosmic ray showers from fluorescence and Cherenkov light measurements
journal, April 2008

  • Unger, M.; Dawson, B. R.; Engel, R.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 588, Issue 3
  • DOI: 10.1016/j.nima.2008.01.100