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Please use this identifier to cite or link to this item: http://hdl.handle.net/2289/3675

Title: Quasi-periodic oscillations in Cen X-3 and the long-term intensity variations
Authors: Raichur, Harsha
Paul, Biswajit
Keywords: Stars: Binaries: General
pulsars: individual (Cen X-3)
Stars: Neutron
X-Rays: Binaries
X-rays: individual (Cen X-3)
X-Rays: Stars
Issue Date: 1-Oct-2008
Publisher: University of Chicago Press for the American Astronomical Society
Citation: Astrophysical Journal, 2008, Vol.685, p1109
Abstract: We have investigated the properties of the quasi-periodic oscillation (QPO) features in the accretion-powered X-ray pulsar Cen X-3 over a period of about 4 years using observations carried out with the Proportional Counter Array (PCA) of the Rossi X-ray Timing Explorer (RXTE). The observations cover a wide range of X-ray intensity of the source in excess of the binary intensity modulation. In 11 of 81 pointings with the PCA, we have detected QPOs with rms intensity fluctuation up to 10%. The QPO peak frequency shows clustering around 40 and 90 mHz, with the QPO frequency having no dependence on X-ray intensity. This indicates that either (1) the observed X-ray luminosity of the source is not related to the mass accretion rate or inner radius of the accretion disk, or (2) the QPO generation mechanism in Cen X-3 is different from the beat frequency model or Keplerian frequency model that is believed to operate in most other transient and persistent X-ray pulsars. We have also found that the rms variation in the 40 mHz QPO feature is not dependent on the X-ray energy, indicating that the origin of the QPO is unlikely to be related to disk absorption.
Description: Restricted Access. An open access version is available at arXiv.org. Articles older than 2 years are open to all at the journal site (alternative location)
URI: http://hdl.handle.net/2289/3675
ISSN: P-ISSN : 0004-637X.
E-ISSN : 1538-4357
Alternative Location: http://adsabs.harvard.edu/abs/2008ApJ...685.1109R
http://arxiv.org/abs/0806.0949
http://dx.doi.org/10.1086/591037
Copyright: 2008 The American Astronomical Society
Appears in Collections:Research Papers (A&A)

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