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Title: A search for point sources of EeV photons

Abstract

Measurements of air showers made using the hybrid technique developed with the fluorescence and surface detectors of the Pierre Auger Observatory allow a sensitive search for point sources of EeV photons anywhere in the exposed sky. A multivariate analysis reduces the background of hadronic cosmic rays. The search is sensitive to a declination band from –85° to +20°, in an energy range from 10{sup 17.3} eV to 10{sup 18.5} eV. No photon point source has been detected. An upper limit on the photon flux has been derived for every direction. The mean value of the energy flux limit that results from this, assuming a photon spectral index of –2, is 0.06 eV cm{sup –2} s{sup –1}, and no celestial direction exceeds 0.25 eV cm{sup –2} s{sup –1}. These upper limits constrain scenarios in which EeV cosmic ray protons are emitted by non-transient sources in the Galaxy.

Authors:
 [1]; ;  [2];  [3];  [4];  [5];  [6];  [7];  [8];  [9];  [10];  [11];  [12];  [13];  [14]; ;  [15];  [16];  [17];  [18] more »; ; « less
  1. Universität Siegen, Siegen (Germany)
  2. Laboratório de Instrumentação e Física Experimental de Partículas (LIP) and Instituto Superior Técnico (IST), Universidade de Lisboa (Portugal)
  3. Osservatorio Astrofisico di Torino (INAF), Università di Torino and Sezione INFN, Torino (Italy)
  4. University of Wisconsin, Madison, WI (United States)
  5. Fermilab, Batavia, IL (United States)
  6. Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris 11, CNRS-IN2P3, Orsay (France)
  7. Universidade de São Paulo, Instituto de Física, São Paulo, SP (Brazil)
  8. Centro Atómico Bariloche and Instituto Balseiro (CNEA-UNCuyo-CONICET), San Carlos de Bariloche (Argentina)
  9. New York University, New York, NY (United States)
  10. Ohio State University, Columbus, OH (United States)
  11. Universidad Tecnológica Nacional—Facultad Regional Buenos Aires, Buenos Aires (Argentina)
  12. Universidad Nacional Autonoma de Mexico, Mexico, D. F. (Mexico)
  13. Universidad de Santiago de Compostela (Spain)
  14. Universität Hamburg, Hamburg (Germany)
  15. Università di Napoli "Federico II" and Sezione INFN, Napoli (Italy)
  16. IMAPP, Radboud University Nijmegen (Netherlands)
  17. University of Wisconsin, Milwaukee, WI (United States)
  18. Universidad Complutense de Madrid, Madrid (Spain)
Publication Date:
OSTI Identifier:
22365649
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 789; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COSMIC RADIATION; EEV RANGE; FLUORESCENCE; GALAXIES; MULTIVARIATE ANALYSIS; PHOTONS; PROTONS; SHOWERS; SURFACES

Citation Formats

Aab, A., Abreu, P., Andringa, S., Aglietta, M., Ahlers, M., Ahn, E. J., Al Samarai, I., Albuquerque, I. F. M., Allekotte, I., Allen, J., Allison, P., Almela, A., Castillo, J. Alvarez, Alvarez-Muñiz, J., Batista, R. Alves, Ambrosio, M., Aramo, C., Aminaei, A., Anchordoqui, L., Arqueros, F., Collaboration: Pierre Auger Collaboration102, and and others. A search for point sources of EeV photons. United States: N. p., 2014. Web. doi:10.1088/0004-637X/789/2/160.
Aab, A., Abreu, P., Andringa, S., Aglietta, M., Ahlers, M., Ahn, E. J., Al Samarai, I., Albuquerque, I. F. M., Allekotte, I., Allen, J., Allison, P., Almela, A., Castillo, J. Alvarez, Alvarez-Muñiz, J., Batista, R. Alves, Ambrosio, M., Aramo, C., Aminaei, A., Anchordoqui, L., Arqueros, F., Collaboration: Pierre Auger Collaboration102, & and others. A search for point sources of EeV photons. United States. doi:10.1088/0004-637X/789/2/160.
Aab, A., Abreu, P., Andringa, S., Aglietta, M., Ahlers, M., Ahn, E. J., Al Samarai, I., Albuquerque, I. F. M., Allekotte, I., Allen, J., Allison, P., Almela, A., Castillo, J. Alvarez, Alvarez-Muñiz, J., Batista, R. Alves, Ambrosio, M., Aramo, C., Aminaei, A., Anchordoqui, L., Arqueros, F., Collaboration: Pierre Auger Collaboration102, and and others. Thu . "A search for point sources of EeV photons". United States. doi:10.1088/0004-637X/789/2/160.
@article{osti_22365649,
title = {A search for point sources of EeV photons},
author = {Aab, A. and Abreu, P. and Andringa, S. and Aglietta, M. and Ahlers, M. and Ahn, E. J. and Al Samarai, I. and Albuquerque, I. F. M. and Allekotte, I. and Allen, J. and Allison, P. and Almela, A. and Castillo, J. Alvarez and Alvarez-Muñiz, J. and Batista, R. Alves and Ambrosio, M. and Aramo, C. and Aminaei, A. and Anchordoqui, L. and Arqueros, F. and Collaboration: Pierre Auger Collaboration102 and and others},
abstractNote = {Measurements of air showers made using the hybrid technique developed with the fluorescence and surface detectors of the Pierre Auger Observatory allow a sensitive search for point sources of EeV photons anywhere in the exposed sky. A multivariate analysis reduces the background of hadronic cosmic rays. The search is sensitive to a declination band from –85° to +20°, in an energy range from 10{sup 17.3} eV to 10{sup 18.5} eV. No photon point source has been detected. An upper limit on the photon flux has been derived for every direction. The mean value of the energy flux limit that results from this, assuming a photon spectral index of –2, is 0.06 eV cm{sup –2} s{sup –1}, and no celestial direction exceeds 0.25 eV cm{sup –2} s{sup –1}. These upper limits constrain scenarios in which EeV cosmic ray protons are emitted by non-transient sources in the Galaxy.},
doi = {10.1088/0004-637X/789/2/160},
journal = {Astrophysical Journal},
number = 2,
volume = 789,
place = {United States},
year = {Thu Jul 10 00:00:00 EDT 2014},
month = {Thu Jul 10 00:00:00 EDT 2014}
}
  • Simultaneous measurements of air showers with the fluorescence and surface detectors of the Pierre Auger Observatory allow a sensitive search for EeV photon point sources. Several Galactic and extragalactic candidate objects are grouped in classes to reduce the statistical penalty of many trials from that of a blind search and are analyzed for a significant excess above the background expectation. The presented search does not find any evidence for photon emission at candidate sources, and combined p -values for every class are reported. Particle and energy flux upper limits are given for selected candidate sources. These limits significantly constrain predictionsmore » of EeV proton emission models from non-transient Galactic and nearby extragalactic sources, as illustrated for the particular case of the Galactic center region.« less
  • Simultaneous measurements of air showers with the fluorescence and surface detectors of the Pierre Auger Observatory allow a sensitive search for EeV photon point sources. Several Galactic and extragalactic candidate objects are grouped in classes to reduce the statistical penalty of many trials from that of a blind search and are analyzed for a significant excess above the background expectation. The presented search does not find any evidence for photon emission at candidate sources, and combined p-values for every class are reported. Particle and energy flux upper limits are given for selected candidate sources. Lastly, these limits significantly constrain predictionsmore » of EeV proton emission models from non-transient Galactic and nearby extragalactic sources, as illustrated for the particular case of the Galactic center region.« less