Measurement of the cosmic ray spectrum above $4{\times}10^{18}$ eV using inclined events detected with the Pierre Auger Observatory

• Main Authors: Ahn, Eun-Joo, Albuquerque, Ivone, Almela, Alejandro, Anchordoqui, Luis, Aranda, Victor Manuel, Arqueros, Fernando, Arsene, Nicusor, Awal, Nafiun, Barber, Kerri B, Bäuml, Julia, Beatty, Jim, Bertou, Xavier, Blanco, Miguel, Brogueira, Pedro, Candusso, Marina, Caramete, Laurentiu, Chiavassa, Andrea, Coluccia, Maria Rita, Cooper, Mathew J, Coutu, Stephane, de Almeida, Rogerio M, Dhital, Niraj, Diaz, Johana Chirinos, Diogo, Francisco, Dobrigkeit, Carola, D'Olivo, Juan Carlos, Escobar, Carlos O, Espadanal, Joao, Falcke, Heino, Fernandes, Mateus, Fick, Brian, Figueira, Juan Manuel, Fratu, Octavian, Gherghel-Lascu, Alexandru, Glaser, Christian, Guarino, Fausto, Haungs, Andreas, Heimann, Philipp, Hollon, Nicholas, Homola, Piotr, Hrabovský, Miroslav, Insolia, Antonio, Kampert, Karl Heinz, Kieckhafer, Roger, Krömer, Oliver, Kunka, Norbert, Latronico, Luca, Lebrun, Paul, Maller, Jennifer, Mantsch, Paul, Mariş, Ioana, Martin, Lilian, Bravo, Oscar Martínez, Meza, Jimmy Masías, Maurel, Detlef, Medina-Tanco, Gustavo, Melo, Diego, Menshikov, Alexander, Mitrica, Bogdan, Molina-Bueno, Laura, Mollerach, Silvia, Navas, Sergio, Niechciol, Marcus, Nosek, Dalibor, Novotny, Vladimir, Olmos-Gilbaja, Victor, Parente, Gonzalo, Piegaia, Ricardo, Pimenta, Mário, Pirronello, Valerio, Porcelli, Alessio, Ravignani, Diego, Risse, Markus, Ristori, Pablo, Rizi, Vincenzo, de Carvalho, Washington Rodrigues, Roulet, Esteban, Saleh, Ahmed, Salina, Gaetano, Sanchez-Lucas, Patricia, Sarkar, Biswaijt, Scarso, Carlos, Schauer, Markus, Scherini, Viviana, Sciutto, Sergio, Segreto, Alberto, Shellard, Ronald C, Sigl, Guenter, Stanca, Denis, Stasielak, Jaroslaw, Supanitsky, A Daniel, Szadkowski, Zbigniew, Tapia, Alex, Tonachini, Aurelio, Galicia, Jose F Valdés, van Aar, Guus, Watson, Alan, Weidenhaupt, Klaus, Zhu, Yue, Zimmermann, Benedikt
• Format: Journal Article
• Language: English
• Published: 26-03-2015
• Subjects: Physics - High Energy Astrophysical Phenomena; Physics - High Energy Physics - Experiment
• DOI: 10.48550/arxiv.1503.07786

JCAP 08 (2015) 049 A measurement of the cosmic-ray spectrum for energies exceeding
$4{\times}10^{18}$ eV is presented, which is based on the analysis of showers
with zenith angles greater than $60^{\circ}$ detected with the Pierre Auger
Observatory between 1 January 2004 and 31 December 2013. The measured spectrum
confirms a flux suppression at the highest energies. Above $5.3{\times}10^{18}$
eV, the "ankle", the flux can be described by a power law $E^{-\gamma}$ with
index $\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)}$ followed by
a smooth suppression region. For the energy ($E_\text{s}$) at which the
spectral flux has fallen to one-half of its extrapolated value in the absence
of suppression, we find
$E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19}$
eV.