Cosmic Rays from the Knee to the Ankle

TL;DR

This paper reviews recent experimental results on cosmic ray energy spectrum and composition from PeV to EeV energies, discussing their implications for understanding the transition from galactic to extragalactic cosmic rays.

Contribution

It provides a comparative analysis of recent measurements from KASCADE-Grande, IceTop, and Tunka-133, and examines the impact of different hadronic interaction models on data interpretation.

Findings

Recent measurements show consistent features in the energy spectrum.

Differences in composition results depend on interaction models used.

The data contribute to understanding the galactic to extragalactic transition.

Abstract

Investigations of the energy spectrum as well as the mass composition of cosmic rays in the energy range of PeVto EeV are important for understanding both, the origin of the galactic and the extragalactic cosmic rays. Recently, three modern experimental installations (KASCADE-Grande, IceTop, Tunka-133), dedicated to investigate this primary energy range, have published new results on the all-particle energy spectrum. In this short review these results are presented and the similarities and differences discussed. In addition, the effects of using different hadronic interaction models for interpreting the measured air-shower data will be examined. Finally, a brief discussion on the question if the present results are in agreement or in contradiction with astrophysical models for the transition from galactic to 10 pagesextragalactic origin of cosmic rays completes this paper.