Extragalactic cosmic rays

TL;DR

This review discusses the current understanding of ultrahigh-energy cosmic rays, focusing on experimental results, potential sources like AGN and hypernovae, and the role of magnetic fields, highlighting constraints and models in the field.

Contribution

It provides a comprehensive overview of UHECR sources, constraints, and models, emphasizing the significance of AGN types and hypernovae as promising origins.

Findings

AGN types like FR-I and Seyfert galaxies are likely UHECR sources

Hypernovae are also strong candidate sources

Magnetic fields influence cosmic ray propagation

Abstract

I review the status of ultrahigh-energy cosmic ray (UHECR) physics.After introducing the main experimental results and summarizing possible intepretations, I discuss observational and theoretical constraints on the sources of UHECRs. I comment also briefly on the role of magnetic fields. Combining these constraints, I argue that luminuous and numerous AGN types as FR-I and Seyfert galaxies, or alternatively hypernovae, are the most promising UHECR sources. Finally, I sketch few of the models presented at the conference before concluding.