Amit Seta (ANU): Cosmic ray propagation in spatially intermittent magnetic fields

Описание: Sydney CPPC Seminar, 9th May 2024

Cosmic rays are a dynamically important component of the interstellar medium in star-forming galaxies and they play a crucial role in enhancing galactic winds and regulating star formation. Their primary influence stems from their interaction with magnetic fields within galaxies. The galactic magnetic field, especially at smaller scales, exhibits spatial intermittency (fields concentrated in random filaments and sheets). This presentation will discuss the role of such structures in the propagation of cosmic rays.

For this study, we conducted test-particle simulations with both intermittent and non-intermittent magnetic fields having identical power spectra. Our findings demonstrate that the cosmic ray diffusion coefficient for low-energy cosmic rays (~ GeV) is higher and the incoming direction of ultrahigh-energy cosmic rays (UHECR, ~ EeV) from the source is better preserved in the presence of such spatially intermittent structures. These results should be considered when interpreting radio (SKA), gamma-ray (CTA), and UHECR (Auger) observations.