Title:
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High-frequency quasi-periodic oscillations from GRS 1915+105 in its C state
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Author:
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Belloni, T.; Soleri, P.; Casella, P.; Méndez, M.; Migliari, Simone
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Other authors:
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Universitat de Barcelona |
Abstract:
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We report the results of a systematic timing analysis of RXTE observations of GRS 1915+105 when the source was in its variability class θ, characterized by alternating soft and hard states on a time-scale of a few hundred seconds. The aim was to examine the high-frequency part of the power spectrum in order to confirm the hectohertz quasi-periodic oscillations (QPO) previously reported from observations from mixed variability behaviours. During the hard intervals (corresponding to state C in the classification of Belloni et al.), we find a significant QPO at a frequency of ~170 Hz, although much broader (Q~2) than previously reported. No other significant peak is observed at frequencies >30 Hz. A time-resolved spectral analysis of selected observations shows that the hard intervals from class θ show a stronger and steeper (Γ = 2.8-3.0) power-law component than hard intervals from other classes. We discuss these results in the framework of hectohertz QPOs reported from GRS 1915+105 and other black hole binaries. |
Subject(s):
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-Observacions astronòmiques -Astronomia de raigs X -Oscil·lacions -Astronomical observations -X-ray astronomy -Oscillations |
Rights:
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(c) Belloni, T. et al., 2006
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Document type:
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Article Article - Published version |
Published by:
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Royal Astronomical Society
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