Constraints on the hosts of UHECR accelerators

TL;DR

This paper explores how the environment around ultrahigh energy cosmic ray sources influences observed spectra and composition, using data to constrain properties like temperature, size, and magnetic fields, with implications for different astrophysical sources.

Contribution

It demonstrates how UHECR and neutrino data can constrain source environment properties and assesses candidate sources like starburst galaxies and galaxy clusters.

Findings

Starburst galaxies are consistent with environmental constraints.

Galaxy clusters may be in tension with these constraints.

Multi-component sources require detailed analysis.

Abstract

Interactions of ultrahigh energy cosmic rays in the surroundings of their accelerators can naturally explain the observed spectrum and composition of UHECRs, including the abundance of protons below the ankle. We show that astrophysical properties of the UHECR source environment such as the temperature, size, and magnetic field can be constrained by UHECR and neutrino data. Applying this to candidate sources with a simple structure shows that starburst galaxies are consistent with these constraints, but galaxy clusters may be in tension with them. For multi-component systems like AGNs and GRBs the results are indicative but customized analysis is needed for definitive conclusions.