Publication date: Feb 2016
Abstract:
Frequencies of the three quasi-periodic oscillation (QPO) modes observed
simultaneously in the accreting black hole GRO J1655-40 are compared
with the predictions of models. Models in which all three QPO signals
are produced at the same radius are considered: these include different
versions of relativistic precession, epicyclic resonance, tidal
disruption, and warped disc models. Models that were originally proposed
to interpret only the twin high-frequency QPOs are generalized here to
interpret also the low-frequency QPO in terms of relativistic nodal
precession. Inferred values of the black hole mass and spin from each
QPO model are compared with the mass measured from optical observations
and the spin inferred from X-ray spectroscopy techniques. We find that
along with the relativistic precession model predicting M = (5.3 ± 0.1)
M☉,a = 0.286 ± 0.004, the so-called total precession model (M
= (5.5 ± 0.1) M☉,a = 0.276 ± 0.003), and the resonance
epicyclic model with beat frequency (M = (5.1 ± 0.1) M☉,a =
0.274 ± 0.003) also satisfy the optical mass test.
Authors:
Stuchlík, Zdeněk; Kološ, Martin;