https://arxiv.org/abs/1901.10216

For a PDF version of the article, click here.

Abstract: The last few years have seen gamma-ray astronomy maturing and advancing in the field of time-domain astronomy, utilizing source variability on timescales over many orders of magnitudes, from a decade down to a few minutes and shorter, depending on the source. This review focuses on some of the key science issues and conceptual developments concerning the timing characteristics of active galactic nuclei (AGN) at gamma-ray energies. It highlights the relevance of adequate statistical tools and illustrates that the developments in the gamma-ray domain bear the potential to fundamentally deepen our understanding of the nature of the emitting source and the link between accretion dynamics, black hole physics, and jet ejection.

Keywords : gamma-rays; emission: non-thermal; variability; origin: jet; origin: black hole

Table of Contents

• INTRODUCTION
• TIMING CHARACTERISTICS
  • Rapid Variability at VHE Energies
  • PDF Shape and Log-Normality
  • PSD and Power-Law Noise
  • Quasi-Periodic Variability

• A POSSIBLE EXAMPLE: PKS 2155-304
• CONCLUSIONS
• REFERENCES