Jul 12 – 23, 2021
Online
Europe/Berlin timezone

LOCAL TURBULENCE AND THE DIPOLE ANISOTROPY OF GALACTIC COSMIC RAYS

Jul 15, 2021, 12:00 PM
1h 30m
03

03

Talk CRD | Cosmic Ray Direct Discussion

Speaker

Yoann GÉNOLINI (Niels Bohr Institute NBIA)

Description

The dipole anisotropy of multi-TeV cosmic rays exhibits a strong energy dependence that is at odds with the predictions of standard isotropic diffusion models. It has been argued that the observed variation in amplitude and phase is a consequence of the global distribution of cosmic ray sources in combination with anisotropic diffusion in our local environment. For a quantitative description
of this effect it is necessary to understand the complicated interplay of cosmic ray diffusion on local and global scales. In this work we study the impact of isotropic magnetic turbulence realisations on cosmic-ray propagation and anisotropy. We define a novel methodology that allows us to quantify generic properties of local and global diffusion with the help of test-particle simulations. We confirm the emergence of local anisotropic diffusion that leads to an alignment of the cosmic ray dipole with the local magnetic field and a reduction of its amplitude in perpendicular directions. We discuss the phenomenological consequences of these findings.

Keywords

Cosmic-ray anisotropy, local turbulence, particle-test simulations

Subcategory Theoretical Results

Primary author

Yoann GÉNOLINI (Niels Bohr Institute NBIA)

Co-author

Markus Ahlers (Niels Bohr Institute)

Presentation materials

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