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High-frequency QPOs as a problem in physics: non-linear resonance

Wlodek Kluzniak·Marek A. Abramowicz·William H. Lee
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Abstract

The presence of a kHz frequency in LMXBs has been expected from scaling laws, by analogy with the QPO phenomenon in HMXB X-ray pulsars. Interpretation of the two kHz frequencies, observed in accreting neutron stars, in terms of non-linear resonance in strong-field gravity led to the prediction of twin QPOs in black hole systems, in a definite frequency ratio (such as 2/3). The imprint of a subharmonic of the 401 Hz rotation rate in the frequencies of the QPOs detected in the accreting millisecond pulsar is at once a signature of non-linear resonance and of coupling between accretion disk modes and the neutron star spin.

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Wlodek Kluzniak, Marek A. Abramowicz, William H. Lee. 2004-02-01. High-frequency QPOs as a problem in physics: non-linear resonance. https://doi.org/10.1063/1.1781058

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