Spectrum and Composition of Ultra-high Energy Cosmic Rays from Semi-relativistic Hypernovae

TL;DR

This paper models ultra-high energy cosmic rays originating from semi-relativistic hypernovae, showing that their spectrum and composition can match observations when considering hypernova ejecta and source spectra.

Contribution

It provides a detailed calculation of the energy spectrum and chemical composition of cosmic rays from semi-relativistic hypernovae, aligning theoretical predictions with observational data.

Findings

Cosmic ray spectrum from hypernovae can match Pierre Auger data.

Chemical composition of cosmic rays reflects hypernova ejecta.

Source spectra influence observed cosmic ray characteristics.

Abstract

It has been suggested that hypernova remnants, with a substantial amount of energy in semi-relativistic ejecta, can accelerate intermediate mass or heavy nuclei to ultra-high energies and provide sufficient amount of energy in cosmic rays to account for the observed flux. We here calculate the expected energy spectrum and chemical composition of ultra-high energy cosmic rays from such semi-relativistic hypernovae. With a chemical composition equal to that of the hypernova ejecta and a flat or hard spectrum for cosmic rays at the sources, the spectrum and composition of the propagated cosmic rays observed at the Earth can be compatible with the measurements by the Pierre Auger Observatory.