A search for point sources of EeV photons

Journal Article · Thu Jul 10 00:00:00 EDT 2014 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/789/2/160· OSTI ID:22365649

Aab, A. ^[1]; Abreu, P.; Andringa, S. ^[2]; Aglietta, M. ^[3]; Ahlers, M. ^[4]; Ahn, E. J. ^[5]; Al Samarai, I. ^[6]; Albuquerque, I. F. M. ^[7]; Allekotte, I. ^[8]; Allen, J. ^[9]; Allison, P. ^[10]; Almela, A. ^[11]; Castillo, J. Alvarez ^[12]; Alvarez-Muñiz, J. ^[13]; Batista, R. Alves ^[14]; Ambrosio, M.; Aramo, C. ^[15]; Aminaei, A. ^[16]; Anchordoqui, L. ^[17]; Arqueros, F. ^[18] ; others, and

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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)

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.

• OSTI ID: 22365649
• Journal Information: Astrophysical Journal, Vol. 789, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
COSMIC RADIATION
EEV RANGE
FLUORESCENCE
GALAXIES
MULTIVARIATE ANALYSIS
PHOTONS
PROTONS
SHOWERS
SURFACES