2024/10/12 by Wenyi Bian, Bian, Wenyi, Gwenael Giacinti +3 · 3 citations
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Dark Matter and Cosmic Phenomena #FOS: Physical sciences #High Energy Astrophysical Phenomena (astro-ph.HE) #Particle Detector Development and Performance
paper · pdf · doi:10.48550/arxiv.2410.09634
openalex publication_date 2024/10/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Simulations of the cosmic-ray (CR) anisotropy down to TeV energies are presented, using turbulence parameters consistent with those inferred from observations of the interstellar medium. We compute the angular power spectra Cℓ of the CR anisotropy obtained from the simulations. We demonstrate that the amplitude of the large scale gradient in the CR density profile affects only the overall normalisation of the Cℓs, without affecting the shape of the angular power spectrum. We show that the power spectrum depends on CR energy, and that it is sensitive to the location of the observer at small ℓ. It is found to flatten at large ℓ, and can be modelled by a broken power-law, exhibiting a break at ℓ ≈ 4. Our computed power spectrum at ∼ 10 TeV fits well HAWC and IceCube measurements. Moreover, we calculate all coefficients of the spherical harmonics and compute the component of the angular power spectrum projected onto the direction of the local magnetic field line. We find that deviations from gyrotropy become increasingly important at higher CR energies and larger values of ℓ.