Small-Scale Anisotropies of Cosmic Rays from Turbulent Flow

Within the classical convection--diffusion approximation, we show that the angular distribution of cosmic rays (CRs) in a highly turbulent flow may exhibit significant small-scale anisotropies. The CR intensity angular power spectrum C_ is then a direct reflection of interstellar turbulence, from which one expects C_∝-γ -1 for 1, where γ is the power-law turbulence spectral index. Observations by IceCube and HAWC at TeV energies can be explained approximately with the Kolmogorov law γ =5/3 with a convection velocity dispersion of 20 km/s on the scale of 10 pc.