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Title: Combined fit of spectrum and composition data as measured by the Pierre Auger Observatory

Abstract

We present a combined fit of a simple astrophysical model of UHECR sources to both the energy spectrum and mass composition data measured by the Pierre Auger Observatory. The fit has been performed for energies above 5 ⋅ 10{sup 18} eV, i.e. the region of the all-particle spectrum above the so-called 'ankle' feature. The astrophysical model we adopted consists of identical sources uniformly distributed in a comoving volume, where nuclei are accelerated through a rigidity-dependent mechanism. The fit results suggest sources characterized by relatively low maximum injection energies, hard spectra and heavy chemical composition. We also show that uncertainties about physical quantities relevant to UHECR propagation and shower development have a non-negligible impact on the fit results.

Authors:
 [1]; ;  [2];  [3];  [4];  [5];  [6]; ;  [7];  [8];  [9];  [10];  [11];
  1. Institute for Mathematics, Astrophysics and Particle Physics (IMAPP), Radboud Universiteit, Nijmegen (Netherlands)
  2. Laboratório de Instrumentação e Física Experimental de Partículas—LIP and Instituto Superior Técnico—IST, Universidade de Lisboa—UL (Portugal)
  3. Osservatorio Astrofisico di Torino (INAF), Torino (Italy)
  4. Laboratoire de Physique Nucléaire et de Hautes Energies (LPNHE), Universités Paris 6 et Paris 7, CNRS-IN2P3 (France)
  5. Universidade de São Paulo, Inst. de Física, São Paulo (Brazil)
  6. Centro Atómico Bariloche and Instituto Balseiro (CNEA-UNCuyo-CONICET) (Argentina)
  7. Instituto de Tecnologías en Detección y Astropartículas (CNEA, CONICET, UNSAM), Centro Atómico Constituyentes, Comisión Nacional de Energía Atómica (Argentina)
  8. Universidad Nacional Autónoma de México, México (Mexico)
  9. Universidad de Santiago de Compostela (Spain)
  10. Gran Sasso Science Institute (INFN), L'Aquila (Italy)
  11. Department of Physics and Astronomy, Lehman College, City University of New York (United States)
Publication Date:
OSTI Identifier:
22679904
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2017; Journal Issue: 04; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASTROPHYSICS; COSMIC RADIATION; COSMIC SHOWERS; COSMOLOGICAL MODELS; ENERGY SPECTRA; INJECTION; MASS; NUCLEI

Citation Formats

Aab, A., Abreu, P., Andringa, S., Aglietta, M., Samarai, I. Al, Albuquerque, I.F.M., Allekotte, I., Almela, A., Andrada, B., Castillo, J. Alvarez, Alvarez-Muñiz, J., Anastasi, G.A., Anchordoqui, L., E-mail: auger_spokespersons@fnal.gov, and and others. Combined fit of spectrum and composition data as measured by the Pierre Auger Observatory. United States: N. p., 2017. Web. doi:10.1088/1475-7516/2017/04/038.
Aab, A., Abreu, P., Andringa, S., Aglietta, M., Samarai, I. Al, Albuquerque, I.F.M., Allekotte, I., Almela, A., Andrada, B., Castillo, J. Alvarez, Alvarez-Muñiz, J., Anastasi, G.A., Anchordoqui, L., E-mail: auger_spokespersons@fnal.gov, & and others. Combined fit of spectrum and composition data as measured by the Pierre Auger Observatory. United States. doi:10.1088/1475-7516/2017/04/038.
Aab, A., Abreu, P., Andringa, S., Aglietta, M., Samarai, I. Al, Albuquerque, I.F.M., Allekotte, I., Almela, A., Andrada, B., Castillo, J. Alvarez, Alvarez-Muñiz, J., Anastasi, G.A., Anchordoqui, L., E-mail: auger_spokespersons@fnal.gov, and and others. Sat . "Combined fit of spectrum and composition data as measured by the Pierre Auger Observatory". United States. doi:10.1088/1475-7516/2017/04/038.
@article{osti_22679904,
title = {Combined fit of spectrum and composition data as measured by the Pierre Auger Observatory},
author = {Aab, A. and Abreu, P. and Andringa, S. and Aglietta, M. and Samarai, I. Al and Albuquerque, I.F.M. and Allekotte, I. and Almela, A. and Andrada, B. and Castillo, J. Alvarez and Alvarez-Muñiz, J. and Anastasi, G.A. and Anchordoqui, L., E-mail: auger_spokespersons@fnal.gov and and others},
abstractNote = {We present a combined fit of a simple astrophysical model of UHECR sources to both the energy spectrum and mass composition data measured by the Pierre Auger Observatory. The fit has been performed for energies above 5 ⋅ 10{sup 18} eV, i.e. the region of the all-particle spectrum above the so-called 'ankle' feature. The astrophysical model we adopted consists of identical sources uniformly distributed in a comoving volume, where nuclei are accelerated through a rigidity-dependent mechanism. The fit results suggest sources characterized by relatively low maximum injection energies, hard spectra and heavy chemical composition. We also show that uncertainties about physical quantities relevant to UHECR propagation and shower development have a non-negligible impact on the fit results.},
doi = {10.1088/1475-7516/2017/04/038},
journal = {Journal of Cosmology and Astroparticle Physics},
number = 04,
volume = 2017,
place = {United States},
year = {Sat Apr 01 00:00:00 EDT 2017},
month = {Sat Apr 01 00:00:00 EDT 2017}
}