Quasi periodic oscillations in black hole binaries

TL;DR

This paper reviews the observed properties of quasi-periodic oscillations (QPOs) in black hole X-ray binaries and discusses the main models proposed to explain their origin, highlighting their significance in understanding accreting systems.

Contribution

It provides a comprehensive overview of QPO observations and summarizes key models explaining their origin in black hole X-ray binaries.

Findings

QPOs are a common feature in black hole X-ray binaries.

Various models have been proposed to explain QPO origins.

QPO properties help probe the physics of accretion processes.

Abstract

Fast time variability is the most prominent characteristic of accreting systems and the presence of quasi periodic oscillations (QPOs) is a constant in all accreting systems, from cataclysmic variables to AGNs, passing through black hole and neutron star X-ray binaries and through the enigmatic ultra-luminous X-ray sources. In this paper I will briefly review the current knowledge of QPOs in black hole X-ray binaries, mainly focussing on their observed properties, but also mentioning the most important models that have been proposed to explain the origin of QPOs over the last decades.