Active Galactic Nuclei - the Physics of Individual Sources and the Cosmic History of Formation and Evolution

TL;DR

This paper reviews the physics of active galactic nuclei, focusing on their central engines, jet phenomena observed across multiple wavelengths, and their cosmic evolution, highlighting recent observational advances and future prospects.

Contribution

It provides a comprehensive overview of AGN physics, integrating recent multi-wavelength observations and discussing their implications for understanding AGN formation and evolution.

Findings

X-ray observations reveal detailed jet structures on kiloparsec scales.

Gamma-ray data from Fermi and Cherenkov telescopes enhance understanding of jet emission mechanisms.

The cosmic history of AGN formation shows significant evolution over cosmic time.

Abstract

In this paper we give a brief review of the astrophysics of active galactic nuclei (AGN). After a general introduction motivating the study of AGNs, we discuss our present understanding of the inner workings of the central engines, most likely accreting black holes with masses between a million and ten billion solar masses. We highlight recent results concerning the jets (collimated outflows) of AGNs derived from X-ray observations (Chandra) of kpc-scale jets and gamma-ray observations of AGNs (Fermi, Cherenkov telescopes) with jets closely aligned with the lines of sight (blazars), and discuss the interpretation of these observations. Subsequently, we summarize our knowledge about the cosmic history of AGN formation and evolution. We conclude with a description of upcoming observational opportunities.