Active Galactic Nuclei with Starbursts: Sources for Ultra High Energy Cosmic Rays

TL;DR

This paper proposes that ultra high energy cosmic rays originate from starburst activity in the radio galaxy Cen A, with heavy nuclei accelerated by relativistic jets and scattered by magnetic fields, explaining observed spectra.

Contribution

It introduces a model linking starburst activity in Cen A to ultra high energy cosmic rays, emphasizing heavy nuclei and magnetic scattering as key factors.

Findings

Ultra high energy cosmic rays are likely heavy nuclei.

Cen A's starburst activity can produce the observed cosmic ray spectrum.

Magnetic scattering explains the isotropy of cosmic ray arrival directions.

Abstract

Ultra high energy cosmic ray events presently show a spectrum, which we interpret here as galactic cosmic rays due to a starburst in the radio galaxy Cen A pushed up in energy by the shock of a relativistic jet. The knee feature and the particles with energy immediately higher in galactic cosmic rays then turn into the bulk of ultra high energy cosmic rays. This entails that all ultra high energy cosmic rays are heavy nuclei. This picture is viable if the majority of the observed ultra high energy events come from the radio galaxy Cen A, and are scattered by intergalactic magnetic fields across most of the sky.