Precessions and parameter constraints from quasiperiodic oscillations in a rotating charged black hole

TL;DR

This paper uses observed quasi-periodic oscillations to constrain the parameters of a rotating charged black hole, revealing how magnetic charge and nonminimal coupling affect orbital precession and oscillation frequencies.

Contribution

It introduces a method combining QPO analysis with MCMC simulations to constrain parameters of a rotating regular magnetic black hole, including magnetic charge and nonminimal coupling.

Findings

Magnetic charge and nonminimal coupling significantly influence epicyclic frequencies.

Regular charged black holes suppress precession frequencies compared to Kerr black holes.

Constraints on black hole parameters are derived from observational QPO data.

Abstract

We investigate quasi-periodic oscillations (QPOs) as a diagnostic tool for probing frame-dragging effects and accretion disk physics in the spacetime of a rotating regular magnetic black hole (BH). Specifically, we analyze the precession of bound orbits and the epicyclic oscillations of test particles under small perturbations in the equatorial plane. We demonstrate how the BH nonminimal coupling parameter (lambda/M^4) and dimensionless magnetic charge (Q/M) significantly influence the three fundamental epicyclic frequencies. By applying the relativistic precession model and employing Markov Chain Monte Carlo simulations (MCMC), we constrain the BH characteristic parameters, including mass, spin, magnetic charge, and nonminimal coupling, using observational QPO data from five X-ray binaries: GRO J1655-40, XTE J1859+226, H1743-322, XTE J1550-564, and GRS 1915+105. Furthermore, we examine the Lense-Thirring, geodetic, and general spin precession frequencies of a test gyroscope attached to a stationary observer around the black hole. Our theoretical results indicate that the regular charged black hole suppresses these precession frequencies compared with the Kerr black hole case.