Implications of Ultra-High-Energy Cosmic Rays for Transient Sources in the Auger Era

TL;DR

This paper investigates the origins of ultra-high-energy cosmic rays from transient sources, estimating their occurrence rates and energy outputs, and discusses implications for candidates like gamma-ray bursts and active galactic nuclei.

Contribution

It provides new bounds on the rate and energy of transient UHECR sources based on recent observations, informing candidate source models.

Findings

Estimated source rate bounds: 0.1 to 10^3.5 Gpc^-3 yr^-1.

Derived energy input per burst: 10^49.5 to 10^54 ergs.

Discussed implications for gamma-ray bursts and active galactic nuclei.

Abstract

We study about ultra-high-energy cosmic rays (UHECRs) from transient sources, propagating in the Galactic and intergalactic space. Based on the recent observational results, we also estimate upper and lower bounds on the rate of transient UHECR sources and required isotropic cosmic-ray energy input per burst as 0.1 Gpc^-3 yr^-1 < rho_0 < 10^3.5 Gpc^-3 yr^-1 and 10^49.5 ergs < E_HECR^iso < 10^54 ergs, through constraining the apparent burst duration, i.e., dispersion in arrival times of UHECRs. Based on these bounds, we discuss implications for proposed candidates such as gamma-ray bursts and active galactic nuclei.