Cherenkov Telescope Array potential in the search for Galactic PeVatrons

TL;DR

This paper evaluates the Cherenkov Telescope Array's ability to identify Galactic PeVatrons, cosmic-ray accelerators, through simulations that establish detection criteria and sensitivity estimates.

Contribution

It introduces a PeVatron figure of merit based on spectral parameters and applies simulations to assess CTA's sensitivity to Galactic PeVatrons.

Findings

Development of a PeVatron detection metric.

Simulation results for HESS J1641-463 as a PeVatron candidate.

CTA sensitivity estimates for Galactic PeVatrons.

Abstract

One of the major scientific objectives of the future Cherenkov Telescope Array (CTA) Observatory is the search for PeVatrons. PeVatrons are cosmic-ray factories able to accelerate nuclei at least up to the knee feature seen in the spectrum of cosmic rays measured near the Earth. CTA will perform a survey of the full Galactic plane at TeV energies and beyond with unprecedented sensitivity. The determination of efficient criteria to identify PeVatron candidates during the survey is essential in order to trigger further dedicated observations. Here, we present results from a study based on simulations to determine these criteria. The outcome of the study is a PeVatron figure of merit, defined as a metric that provides relations between spectral parameters and spectral cutoff energy lower limits. In addition, simulations of the PeVatron candidate HESS J1641$-$463 and its parental particle spectrum are presented and discussed. Eventually, our work is applied to simulated population of Galactic PeVatrons, with the aim to determine the sensitivity of CTA.