The physical nature of the short-period RS CVn system DV Psc |
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| Authors: | X B Zhang R X Zhang |
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| Institution: | INAF –Osservatorio Astronomico di Brera, Via E. Bianchi 46, I-23807 Merate (LC), Italy;SRON, Netherlands Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrecht, the Netherlands;Astronomical Institute Anton Pannekoek, University of Amsterdam, Kruislaan 403, 1098 SJ Amsterdam, the Netherlands;MIT Kavli Institute for Astrophysics and Space Research, 70 Vassar Street, Cambridge, MA 02139, USA |
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| Abstract: | We re-examine the correlation between the frequencies of upper and lower kHz quasi-periodic oscillations (QPO) in bright neutron star low-mass X-ray binaries. By including the kHz QPO frequencies of the X-ray binary Cir X-1 and two accreting millisecond pulsars in our sample, we show that the full sample does not support the class of theoretical models based on a single resonance, while models based on relativistic precession or Alfvén waves describe the data better. Moreover, we show that the fact that all sources follow roughly the same correlation over a finite frequency range creates a correlation between the linear parameters of the fits to any subsample. |
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| Keywords: | accretion accretion discs stars: neutron X-rays: binaries |
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