EDP Sciences
Free access
Volume 440, Number 2, September III 2005
Page(s) L25 - L28
Section Letters
DOI http://dx.doi.org/10.1051/0004-6361:200500163

A&A 440, L25-L28 (2005)
DOI: 10.1051/0004-6361:200500163


QPOs in cataclysmic variables and in X-ray binaries

W. Kluzniak1, 2, 3, J.-P. Lasota1, 4, M. A. Abramowicz1, 5 and B. Warner6

1  Nordita, Blegdamsvej 17, 2100 Copenhagen, Denmark
    e-mail: lasota@iap.fr
2  Institute of Astronomy, Univ. of Zielona Góra, ul. Lubuska 2, 65-265 Zielona Góra, Poland
3  Copernicus Astronomical Center, ul. Bartycka 18, 00-716 Warszawa, Poland
4  Institut d'Astrophysique de Paris, UMR 7095 CNRS, Univ. P. & M. Curie, 98bis Bd. Arago, 75014 Paris, France
5  Department of Astrophysics, Göteborg University, Göteborg, Sweden
6  Department of Astronomy, University of Cape Town, Rondebosch 7700, South Africa

(Received 4 May 2005 / Accepted 29 July 2005)

Recent observations, reported by Warner and Woudt, of Dwarf Nova Oscillations (DNOs) exhibiting frequency drift, period doubling, and 1:2:3 harmonic structure, can be understood as disc oscillations that are excited by perturbations at the spin frequency of the white dwarf or of its equatorial layers. Similar quasi-periodic disc oscillations in black hole low-mass X-ray binary (LMXB) transients in a 2:3 frequency ratio show no evidence of frequency drift and correspond to two separate modes of disc oscillation excited by an internal resonance. Just as no effects of general relativity play a role in white dwarf DNOs, no stellar surface or magnetic field effects need be invoked to explain the black hole QPOs.

Key words: accretion, accretion discs -- novae, cataclysmic variables -- X-ray: binaries

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© ESO 2005