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 l is then a direct reflection of interstellar turbulence, from which one expects C l proportional to l -gamma-1 for l >> 1, where gamma is the power-law turbulence spectral index. Observations by IceCube and HAWC at TeV energies can be explained approximately with the Kolmogorov law gamma = 5/3 with a convection velocity dispersion of 20 km s-1 on the scale of 10 pc.