Twin peak QPOs frequencies in microquasars and Sgr A*. The resonance and other orbital models
Abstract
In all four microquasars which show twin peak kHz QPOs, the ratio of the two frequencies is 3:2. This rather strongly supports the suggestion by Abramowicz, M. A. and Kluzniak [W. Abramowicz, M. A. and Kluzniak, W., (2001). A precise determination of black hole spin in GRO J1655-40. Astronomy and Astrophysics, 374:L19] that twin peak kHz QPOs are due to a resonance between some modes of accretion disk oscillations. Detailed studies of this suggestion revealed that several such non-linear resonances are present in nearly Keplerian disks in strong gravity. Here, we fit to observations predictions of the resonance hypothesis for two particular types of non-linear resonances between vertical and radial epicyclic frequencies. For three microquasars with known masses, the fits give an accurate estimate of the spin.
- Publication:
-
RAGtime 4/5: Workshops on black holes and neutron stars
- Pub Date:
- December 2004
- Bibcode:
- 2004ragt.meet....1A
- Keywords:
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- LMXRB and Galactic Centre black holes;
- X-ray variability;
- observations;
- theory