Measurement of the cosmic-ray sidereal anisotropy near 1500 GV

Journal Article · Tue Sep 15 04:00:00 EDT 1981 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/159246· OSTI ID:5849991

Cutler, D J; Bergeson, H E; Davis, J F; Groom, D E

A large, underground muon detector has been used to search for periodic variations in the cosmic-ray flux at a median rigidity of 1.5 x 10/sup 12/ V. The detector has operated at an average rate of 4.47 Hz for most of a 2.7 year interval starting 1978 January 1. A peak with relative amplitude (4.1/sup +1.2//sub -0.9/) x 10/sup -4/ is observed in the Fourier transform of data at the sidereal frequency, where the errors are 68% confidence limits based upon an off-center Rayleigh distribution. After correction for solar motion, the projected anisotropy is (6.4/sup +1.2//sub -1.0/) x 10/sup -4/ at right ascension 3/sup h/.8 +- 0/sup h/.7. We observe a second sidereal harmonic with amplitude (2.8/sup +0.9//sub -0.7/) x 10/sup -4/ at ..cap alpha.. = 7/sup h/.8 +- 1/sup h/.4. There is no discernible peak at the antisidereal frequency, and the small amplitude at the solar frequency implies an upper atmospheric diurnal temperature amplitude of < or approx. =0/sup .//sup 0/1C.

• Research Organization: Physics Department, University of Utah
• OSTI ID: 5849991
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 248:3; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640101* -- Astrophysics &amp; Cosmology-- Cosmic Radiation
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANISOTROPY
CHARGED PARTICLE DETECTION
COSMIC MUONS
COSMIC RADIATION
COSMIC RAY DETECTION
DATA ANALYSIS
DETECTION
ELEMENTARY PARTICLES
FERMIONS
HARMONICS
IONIZING RADIATIONS
LEPTONS
MEASURING INSTRUMENTS
MUON DETECTION
MUONS
OSCILLATIONS
RADIATION DETECTION
RADIATION DETECTORS
RADIATION FLUX
RADIATIONS
SCINTILLATION COUNTERS
VARIATIONS