Low Frequency Quasi Periodic Oscillations and Shocks in Accretion onto Black Hole

TL;DR

This paper investigates the physical origin of low-frequency quasi-periodic oscillations in black hole X-ray binaries, proposing shock oscillations in accretion flows as a key mechanism, and confirms Compton cooling's role in explaining observations.

Contribution

It introduces a minimal-parameter model linking QPOs to shock oscillations and applies it to multiple black hole candidates, strengthening the shock oscillation scenario.

Findings

Anti-correlation between QPO frequency and shock location.

Compton cooling can explain observed QPOs.

Model applies to numerous BH candidates.

Abstract

Low-frequency quasi-periodic oscillations (LFQPOs) have been routinely observed in black hole X-ray binaries (BHXRBs). These LFQPOs can be explained by axisymmetric shock oscillation in accretion flow around a rotating black hole. We address the physical origin of Type-C LFQPOs in BHXRBs observed by the Rossi X-ray Timing Explorer satellite considering a minimum number of free parameters, namely, specific energy and specific angular momentum of the infalling matter for a given set of BH mass and spin parameter. We apply the solution for a large number of BH candidates to further strengthen the scenario of an anti-correlation between the QPO frequency and the location of the shock. Our study also confirms that Compton cooling can be sufficient to explain the observed QPOs.