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Anisotropy and corotation of galactic cosmic rays.
1Department of Physics, Hirosaki University, Hirosaki 036-8561, Japan.
Science (New York, N.Y.)
|October 21, 2006
Summary
Researchers measured Galactic cosmic ray anisotropy using the Tibet Air Shower Arrays. A new anisotropy component was found near the Cygnus region, fading at higher energies, indicating cosmic ray corotation with magnetic fields.
Area of Science:
- Cosmic ray physics
- Astrophysics
- Particle astrophysics
Background:
- Galactic cosmic rays exhibit near-isotropy due to Milky Way magnetic field influence.
- Understanding cosmic ray anisotropy is crucial for astrophysics and particle physics.
Purpose of the Study:
- To present high-precision, two-dimensional anisotropy measurements of cosmic rays.
- To investigate cosmic ray behavior at energies from a few to several hundred teraelectronvolts (TeV).
- To uncover new components of cosmic ray anisotropy.
Main Methods:
- Utilized a large dataset from the Tibet Air Shower Arrays.
- Performed two-dimensional anisotropy measurements for cosmic rays.
- Analyzed data for energies ranging from a few to several hundred TeV.
Main Results:
- Revealed finer details of previously known cosmic ray anisotropies.
- Discovered a new component of Galactic cosmic ray anisotropy in sidereal time, originating from the Cygnus region.
- Observed the fading of all anisotropy components at energies up to a few hundred TeV.
Conclusions:
- The fading of anisotropies suggests Galactic cosmic rays corotate with the local Galactic magnetic environment at higher energies.
- These findings impact our understanding of cosmic rays, supernovae, magnetic fields, and galactic dynamics.
- The study provides new insights into the complex interplay within the heliospheric and Galactic environments.
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