Time variability of TeV cosmic ray sky map

Abstract

The variation in the intensity of cosmic rays at small angular scales is attributed to the interstellar turbulence in the vicinity of the Solar system. We show that {a turbulent origin of the small-scale structures implies that} the morphology of the observed cosmic-ray intensity skymap varies with our location in the interstellar turbulence. The gyroradius of cosmic rays is shown to be the length scale associated with an observable change in the skymap over a radian angular scale. The extent to which the intensity \mpo{at a certain} angular scale varies is proportional to the change in our location with a maximum change of about the amplitude of intensity variation at that scale in the existing skymap.} We suggest that for TeV cosmic rays a measurable variation could occur over a time scale of a decade due to the Earth's motion through the interstellar medium, if interstellar turbulence persists down to the gyroradius, \mpo{about $00\mu \mathrm{pc}$ for TeV-ish cosmic rays}. Observational evidence of the variability, or an absence of it, could provide a useful insight into the physical origin of the small-scale anisotropy.

References in corpus (18)

• HEALPix -- a Framework for High Resolution Discretization, and Fast Analysis of Data Distributed on the Sphere
• Cosmic-ray propagation and interactions in the Galaxy
• Anisotropy and Corotation of Galactic Cosmic Rays
• Discovery of Localized Regions of Excess 10-TeV Cosmic Rays
• Diffusive propagation of cosmic rays from supernova remnants in the Galaxy. I: spectrum and chemical composition
• Anisotropy in Cosmic-Ray Arrival Directions in the Southern Hemisphere with Six Years of Data from the IceCube Detector
• Local Magnetic Turbulence and TeV-PeV Cosmic Ray Anisotropies
• A common solution to the cosmic ray anisotropy and gradient problems
• Observation of Small-scale Anisotropy in the Arrival Direction Distribution of TeV Cosmic Rays with HAWC
• Anisotropy of TeV Cosmic Rays and the Outer Heliospheric Boundaries
• Anomalous Anisotropies of Cosmic Rays from Turbulent Magnetic Fields
• Understanding TeV-band cosmic-ray anisotropy
• Small-Scale Anisotropies of Cosmic Rays from Relative Diffusion
• Cosmic Ray Small Scale Anisotropies and Local Turbulent Magnetic Fields
• The problem of small angular scale structure in the cosmic ray anisotropy data
• The isotropy problem of Sub-ankle Ultra-high energy cosmic rays
• Ultrahigh Energy Cosmic Rays: A Galactic Origin?
• Is the Galactic Cosmic Ray Spectrum Constant in Time?

Cited by in corpus (2)

• Test particle simulations of cosmic rays
• Chaotic Behavior of Trapped Cosmic Rays