Plasmas, particles and photons

  • During the past decennia, progress in the area of high-energy astroparticle physics was exceptional, mainly due to the great success of the bridging of particle- and astrophysics both in theory and in the instrumentation of astroparticle physics observatories. Multimessenger data coming from charged cosmic-ray-, gamma-ray- and neutrino-observatories start to shed more and more light on the nature and origin of cosmic rays. At the same time, the development of methods for the investigation of cosmic-ray transport, acceleration and interaction has advanced to the true potential of tying these different pieces of multimessenger data together, this way closing in on the origin of cosmic rays. In recent years, this rapid interplay between modeling and observations has made it clear that it is essential to add the ingredient of plasma physics to the problem. It has been shown that even the interpretation of data of highly relativistic cosmic rays at TeV energies and above is in need of a proper modeling of the plasma physics involved. One of the most important examples is the understanding of wave-particle interactions. In simulations of cosmic-ray transport in the Galaxy, the cosmic-ray diffusion coefficient is typically approximated with a Kolmogorov-type cascade model, resulting in an energy-dependent parallel diffusion coefficient \(\kappa_{\parallel}\propto E^{\gamma}\) with \(\gamma\) = 1/3. Here, we show how the energy dependence of the diffusion coefficient can be investigated systematically as a function of \(\delta B/B\). The complex energy behavior that goes well beyond a simple powerlaw interpretation will be presented together with a formal definition of an energy range that indeed can be approximated as a powerlaw. These results are applied to cosmic-ray transport in the Milky Way. Finally, the transition between the ballistic and diffusive regime will be investigated for astrophysical sources with special focus on relativistic plasmoids of active galaxies.

Download full text files

Export metadata

Additional Services

Share in Twitter Search Google Scholar
Author:Julia Becker TjusORCiDGND
Parent Title (English):Plasma physics and controlled fusion
Subtitle (English):spotlights on multimessenger astronomy
Publisher:IOP Publishing
Place of publication:Bristol, Vereinigtes Königreich
Document Type:Article
Date of Publication (online):2024/02/16
Date of first Publication:2022/03/14
Publishing Institution:Ruhr-Universität Bochum, Universitätsbibliothek
Tag:ballistic propagation; cosmic-ray diffusion; high-energy astrophysics; plasma-astrophysics; transport equation
Issue:4, Artikel 044013
First Page:044013-1
Last Page:044013-6
Institutes/Facilities:Institut für Theoretische Physik IV, Research Department Plasmas with Complex Interactions, Ruhr Astroparticle and Plasma Physics Center
Institut für Theoretische Physik IV
Dewey Decimal Classification:Naturwissenschaften und Mathematik / Physik
open_access (DINI-Set):open_access
faculties:Fakultät für Physik und Astronomie
Licence (English):License LogoCreative Commons - CC BY 4.0 - Attribution 4.0 International