Publication date: Jan 2004
Abstract:
Many Galactic black hole and neutron star sources in low X-ray mass
binaries show QPOs (quasi periodic oscillations) in their observed X-ray
fluxes, i.e. peaks in the Fourier variability power spectra. Pairs of
twin peaks are observed, and in black-hole systems their frequencies
(upp), (down) are in rational ratios. For example, in all four
microquasars with twin peaks observed, (upp):(down) = 3:2. The rational
ratios have been postulated in a model that explained twin peak QPOs as
a non-linear resonance between modes of accretion disk oscillations. For
those microquasars where the mass of the X-ray source is known, we
determine the black-hole spin, following from the observed QPO
frequencies within various models of resonance.
Authors:
Abramowicz, Marek A.; Kluzniak, Wlodek; Stuchlik, Zdenek; Torok, Gabriel;