Fast variability from black-hole binaries

TL;DR

This paper reviews the complex fast variability observed in X-ray emissions from black-hole binaries, discussing models and diagnostics that reveal matter dynamics and relativistic effects near black holes.

Contribution

It provides a comprehensive review of observational data and models, highlighting diagnostics that probe the strong-field relativistic environment around black holes.

Findings

Identification of key observational diagnostics

Insights into matter motions near black holes

Potential to observe strong-field relativistic effects

Abstract

Currently available information on fast variability of the X-ray emission from accreting collapsed objects constitutes a complex phenomenology which is difficult to interpret. We review the current observational standpoint for black-hole binaries and survey models that have been proposed to interpret it. Despite the complex structure of the accretion flow, key observational diagnostics have been identified which can provide direct access to the dynamics of matter motions in the close vicinity of black holes and thus to the some of fundamental properties of curved spacetimes, where strong-field general relativistic effects can be observed.