Extragalactic source population studies at very high energies in the Cherenkov Telescope Array era

TL;DR

This paper analyzes how the Cherenkov Telescope Array will enhance the study of extragalactic gamma-ray sources, especially blazars, by leveraging simulations based on current catalogs and expected array configurations.

Contribution

It provides a detailed simulation-based assessment of CTA's capabilities to study extragalactic gamma-ray sources, highlighting expected improvements over current instruments.

Findings

CTA will significantly increase the detection of extragalactic sources.

Simulations show improved sensitivity and energy coverage for blazar studies.

Key Science Projects will benefit from enhanced observational capabilities.

Abstract

The Cherenkov Telescope Array (CTA) is the next generation ground-based $\gamma$-ray observatory. It will provide an order of magnitude better sensitivity and an extended energy coverage, 20 GeV - 300 TeV, relative to current Imaging Atmospheric Cherenkov Telescopes (IACTs). IACTs, despite featuring an excellent sensitivity, are characterized by a limited field of view that makes the blind search of new sources very time inefficient. Fortunately, the $\textit{Fermi}$-LAT collaboration recently released a new catalog of 1,556 sources detected in the 10 GeV - 2 TeV range by the Large Area Telescope (LAT) in the first 7 years of its operation (the 3FHL catalog). This catalog is currently the most appropriate description of the sky that will be energetically accessible to CTA. Here, we discuss a detailed analysis of the extragalactic source population (mostly blazars) that will be studied in the near future by CTA. This analysis is based on simulations built from the expected array configurations and information reported in the 3FHL catalog. These results show the improvements that CTA will provide on the extragalactic TeV source population studies, which will be carried out by Key Science Projects as well as dedicated proposals.