AGN Physics with the Cherenkov Telescope Array

TL;DR

The Cherenkov Telescope Array will significantly advance very high energy gamma-ray astronomy, enabling detailed studies of Active Galactic Nuclei, their spectra, variability, and related cosmological phenomena.

Contribution

This paper discusses the current status and scientific potential of CTA for AGN physics, including detection predictions and implications for fundamental physics.

Findings

CTA will detect many new AGN sources.

It will provide detailed spectra and variability data.

Constraints on extragalactic background light and magnetic fields will improve.

Abstract

The Cherenkov Telescope Array (CTA), currently in its Preparatory Phase, will be the first open observatory for very high energy gamma-rays from galactic and extragalactic sources. The international consortium behind CTA is preparing the construction of two large arrays of Cherenkov telescopes in the Northern and Southern Hemispheres with a performance that will be significantly improved compared to the current generation of arrays. Its increased sensitivity and energy range will give CTA access to a large population of Active Galactic Nuclei (AGN) not yet detected at very high energies and provide much more details on known TeV sources. While the low end of the CTA energy coverage will close the current gap with the Fermi-LAT band, its high energy coverage will open a new window on the sky and help us understand the intrinsic shape of the hardest blazar spectra. We outline the current status of CTA and discuss the science case for AGN physics with the observatory. Predictions for source detections based on extrapolations of Fermi-LAT spectra are discussed. An overview is given of prospects for the detection of extended emission from radio galaxies, of rapid variability, and spectral features. The observation of AGN with CTA will also improve current constraints on the distribution of the extragalactic background light, the strength of the intergalactic magnetic field and Lorentz invariance violation.