Search for First Harmonic Modulation in the Right Ascension Distribution of Cosmic Rays Detected at the Pierre Auger Observatory

Journal Article · Tue Mar 01 00:00:00 EST 2011 · Astropart.Phys.34:627-639,2011

DOI:https://doi.org/10.1016/j.astropartphys.2010.12.007· OSTI ID:1010702

Abreu, P; Aglietta, M; Ahn, E J; Allard, D; Allekotte, I; Allen, J; Allison, P; Alvarez Castillo, J; Alvarez-Muniz, J; Ambrosio, M; Aminaei, A

We present the results of searches for dipolar-type anisotropies in different energy ranges above 2.5 x 10{sup 17} eV with the surface detector array of the Pierre Auger Observatory, reporting on both the phase and the amplitude measurements of the first harmonic modulation in the right-ascension distribution. Upper limits on the amplitudes are obtained, which provide the most stringent bounds at present, being below 2% at 99% C.L. for EeV energies. We also compare our results to those of previous experiments as well as with some theoretical expectations.

• Research Organization: Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: AC02-07CH11359
• OSTI ID: 1010702
• Report Number(s): FERMILAB-PUB-11-159-AD-AE-CD-TD; arXiv eprint number arXiv:1103.2721; TRN: US201108%%530
• Journal Information: Astropart.Phys.34:627-639,2011, Vol. 34, Issue 8; ISSN 0927-6505
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AMPLITUDES
DISTRIBUTION
ENERGY RANGE
HARMONICS
MODULATION
Astrophysics