Accretion of matter and spectra of Binary X-ray sources in Massive Gravity

TL;DR

This paper investigates how massive gravity theories affect accretion disks and X-ray spectra of binary black hole systems, providing a way to constrain alternative gravity models using observational data.

Contribution

It introduces a modified Schwarzschild-de Sitter spacetime in massive gravity and analyzes its impact on accretion disk properties and X-ray spectra.

Findings

Massive gravity alters accretion disk dynamics.

Spectral features can constrain gravity theories.

Potential to test gravity models with X-ray observations.

Abstract

We study low-mass binary X-ray sources involving stellar mass black holes within massive gravity. Regarding the accretion disk, we adopt the standard model for an optically thick, cool, and geometrically thin disk by Shakura-Sunyaev. For the gravitational field generated by the black hole, we consider the analogue of the Schwarzschild-de Sitter space-time of Einstein's theory in massive gravity, for which we found an additional term linear in the radial coordinate. Then, we compute the radial velocity, the energy density and the pressure as a function of the radial coordinate, and the X-ray emission's soft spectral component expected from the disk. We also investigated in detailed the impact of this new geometry. Our result indicates that by using observed spectra from confirmed X-ray binaries involving astrophysical black holes, we can put strong constraints on alternative theories of gravity.