Accretion disks around black holes in modified strong gravity

PÉREZ, D.; ROMERO, G. E. ; PEREZ-BERGLIAFFA, S. E.

ASTRONOMY AND ASTROPHYSICS

EDP SCIENCES S A

Lugar: Paris; Año: 2013 vol. 551 p. 1 - 15

0004-6361

Context. Stellar-mass black holes offer what is perhaps the best scenario to test theories of gravity in the strong-field regime. In particular, f(R) theories, which have been widely discus in a cosmological context, can be constrained through realistic astrophysical models of phenomena around black holes. Aims: We aim at building radiative models of thin accretion disks for both Schwarzschild and Kerr black holes in f(R) gravity. Methods: We study particle motion in f(R)-Schwarzschild and Kerr space-times. Results: We present the spectral energy distribution of the accretion disk around constant Ricci scalar f(R) black holes, and constrain specific f(R) prescriptions using features of these systems. Conclusions: A precise determination of both the spin and accretion rate onto black holes along with X-ray observations of their thermal spectrum might allow to identify deviations of gravity from general relativity. We use recent data on the high-mass X-ray binary Cygnus X-1 to restrict the values of the parameters of a class of f(R) models.