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Kilohertz QPO in Low Mass X-Ray Binaries: an Overview

Published online by Cambridge University Press:  12 April 2016

M. van der Klis
M. van der Klis*
Affiliation:
Astronomical Institute “Anton Pannekoek” and Center for High-Energy Astrophysics, University of Amsterdam, Kruislaan 403, 1098 SJ Amsterdam, The Netherlands

Abstract

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I review the current status of the investigations of the kilohertz quasi-periodic oscillations that have been discovered in low-mass Xray binaries (LMXBs) with NASA’s Rossi X-ray Timing Explorer (RXTE) since February 1996. Seven sources have now shown this new phenomenon, one Z source (Sco X–l) and 6 atoll sources (all X-ray bursters), and some patterns are beginning to emerge. The frequencies of the oscillations are between 500 and 1200 Hz. They can be coherent for more than 102 cycles, but a more typical coherence is several 101. Amplitudes are between 0.5 and 16% (rms) of the total flux. Most sources show double kHz peaks separated by a few 102 Hz, which move up and down in frequency together. In Sco X–l the peak frequencies systematically increase, and the peak separation systematically decreases, with Ṁ. In 4U 1728–34 a third oscillation is seen at a frequency equal to the difference frequency of the two kHz peaks, but only during X-ray bursts. A simple interpretation in terms of a beat-frequency model with the difference frequency being the neutron star’s spin, as suggested by this result, is inconsistent with the fact that in Sco X–l the peak separation varies.

Type
Part 8. X-Ray Binaries, Transients and Super-Soft Sources
Information
International Astronomical Union Colloquium , Volume 163: Accretion Phenomena and Related Outflows , 1997 , pp. 347 - 350
Copyright
Copyright © Astronomical Society of the Pacific 1997

References

1: Ford, et al. 1996 IAUC 6426, Kaaret, et al. 1996 these proc;Google Scholar
2: Van der, Klis et al. 1996 IAUC 6428, Mendez, et al. 1996 in prep., Wijnands, et al. in prep.;Google Scholar
3: Van, Paradijs et al. 1996 IAUC 6336, Berger, et al. 1996 ApJ 469 L13;Google Scholar
4: Van der, Klis et al. 1996 IAUC 6319, 6424, ApJ 469 L1, and in prep.;Google Scholar
5: Zhang, W. et al. 1996 ApJ 469 L17;CrossRefGoogle Scholar
6: Strohmayer, et al. 1996 IAUC 6320, 6387, ApJ 469 L9;Google Scholar
7: Morgan, et al. 1996 IAUC 6437;Google Scholar
8: Wijnands, et al. 1996 IAUC 6447 and in prep.Google Scholar