Testing General Relativity using Quasi-Periodic Oscillations from X-ray Black Holes: XTE J1550-564 and GRO J1655-40

TL;DR

This study tests General Relativity in the strong gravity regime by analyzing quasi-periodic oscillations from black hole X-ray binaries, extending models to include potential deviations from GR and constraining them with observational data.

Contribution

It introduces an extended Relativistic Precession Model using Kerr-Newman-deSitter spacetime to test for deviations from GR with QPO data from black holes.

Findings

Deviations from GR are constrained to be less than one part per thousand.

The extended model successfully fits the QPO data from XTE J1550-564 and GRO J1655-40.

The method improves constraints on black hole spacetime properties.

Abstract

We use the Relativistic Precession Model (RPM) (Stella et al. 1999a) and quasi-periodic oscillation (QPO) observations from the Rossi X-ray Timing Explorer to derive constraints on the properties of the black holes that power these sources and to test General Relativity (GR) in the strong field regime. We extend the techniques outlined by Motta et al. (2014a,b) to use pairs of simultaneously measured QPOs, rather than triplets, and extend the underlying spacetime metric to constrain potential deviations from the predictions of GR for astrophysical black holes. To do this, we modify the RPM model to a Kerr-Newman-deSitter spacetime and model changes in the radial, ecliptic, and vertical frequencies. We compare our models with X-ray data of XTE J1550-564 and GRO J1655-40 using robust statistical techniques to constrain the parameters of the black holes and the deviations from GR. For both sources we constrain particular deviations from GR to be less than one part per thousand.