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Quasi-Periodic Oscillations in Black Hole Candidates as an Indicator of Transition Between Low and High States

Rutledge, Robert E. and Lewin, Walter H. G. and van der Klis, Michiel and van Paradijs, Jan and Dotani, Tadayasu and Vaughan, Brian and Belloni, Tomaso and Oosterbroek, Tim and Kouveliotou, Chryssa (1999) Quasi-Periodic Oscillations in Black Hole Candidates as an Indicator of Transition Between Low and High States. Astrophysical Journal Supplement Series, 124 (1). pp. 265-283. ISSN 0067-0049. doi:10.1086/313251.

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By comparing positions on a spectral color-color diagram from 10 black hole candidates (BHCs) observed with Ginga (1354-64, 1826-24, 1630-47, LMC X-1, LMC X-3, GS 2000+25, GS 2023+33, GS 1124-68, Cyg X-1, and GX 339-4) with the observed broadband noise (BBN) (0.001-64 Hz) and quasi-periodic oscillation (QPO) variability, we find that the "very high state" is spectrally intermediate to the soft/high state and hard/low state. We find a transition point in spectral hardness where the dependence of the BHC QPO centroid frequency (of GS 1124-68 and GX 339-4) on spectral hardness switches from a correlation to an anticorrelation; where the BBN variability switches from high state to low state; and where the spectral hardness of the QPO relative to that of the BBN variability is a maximum. This coincidence of changing behavior in both the QPO and the broadband variability leads us to hypothesize that the QPO is due to interaction between the physical components which dominate the behaviors of BHCs when they occupy the hard/low and soft/high states. We conclude that these QPOs should be observed from BHCs during transition between these two states. Comparison with QPO and BBN behavior observed during the 1996 transition of Cyg X-1 supports this hypothesis. We also report 1-3 Hz QPOs observed in GS 2000+25 and Cyg X-1 in the hard/low state, and we compare these to the QPOs observed in GS 1124-68 and GX 339-4.

Item Type:Article
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URLURL TypeDescription
van der Klis, Michiel0000-0003-0070-9872
Kouveliotou, Chryssa0000-0003-1443-593X
Additional Information:© 1999. The American Astronomical Society. Received 1998 July 3; accepted 1999 February 23. R. R. is grateful to W. Cui for providing the unpublished spectral hardness ratios measured from Cyg X-1. R. R. is also grateful to L. Bildsten for his hospitality at UC Berkeley where this work was completed. T. O. acknowledges an ESA Research Fellowship. M. K. gratefully acknowledges the Visiting Miller Professor Program of the Miller Institute for Basic Research in Science (UCB). W. H. G. L. acknowledges support from NASA.
Group:Space Radiation Laboratory
Funding AgencyGrant Number
European Space Agency (ESA)UNSPECIFIED
Miller Institute for Basic Research in ScienceUNSPECIFIED
Subject Keywords:black hole physics; stars: individual (Cygnus X-1, GX 339-4, GS 1124-68); stars: oscillations; X-rays: stars
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Other Numbering System NameOther Numbering System ID
Space Radiation Laboratory1999-65
Issue or Number:1
Record Number:CaltechAUTHORS:20150218-154942939
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:54963
Deposited By: Deborah Miles
Deposited On:24 Feb 2015 20:39
Last Modified:10 Nov 2021 20:39

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