Quasi-periodic Oscillations and Spectral States in GRS 1915+105

We present results from the analysis of X-ray energy spectra and quasi-periodic oscillations (QPOs) from a set of observations that samples a broad range of time variability in GRS 1915+105. We first demonstrate that the frequency and integrated amplitude of a 0.5-10 Hz QPO is correlated with the apparent temperature of the accretion disk for the majority of observations. We then show that the behavior of GRS 1915+105 exhibits two distinct modes of accretion. In the first mode, the QPO is present between 0.5 and 10 Hz and variability in the source luminosity is dominated by the power-law component. In the second mode, the QPO is absent and the changes in the luminosity are dominated by thermal emission from the accretion disk. We find that the color radius and temperature of the inner accretion disk are empirically related by Rcol ∝ T + const. We discuss these results in terms of ongoing efforts to explain the origin of both the QPOs and the hard X-ray component in the spectrum of GRS 1915+105.

[1]  J. Orosz,et al.  X-Ray Nova XTE J1550–564: RXTE Spectral Observations , 1999, astro-ph/9903395.

[2]  R. Taam,et al.  Variable-Frequency Quasi-periodic Oscillations from the Galactic Microquasar GRS 1915+105 , 1999, astro-ph/9901050.

[3]  R. P. Fender,et al.  MERLIN observations of relativistic ejections from GRS 1915+105 , 1998, astro-ph/9812150.

[4]  J. Orosz,et al.  RXTE Spectral Observations of the 1996-1997 Outburst of the Microquasar GRO J1655–40 , 1998, astro-ph/9809195.

[5]  G. Pooley,et al.  Infrared synchrotron oscillations in GRS 1915+105 , 1998, astro-ph/9806073.

[6]  Penn State,et al.  RXTE Observations of 0.1-300 Hz Quasi-periodic Oscillationsin the Microquasar GRO J1655–40 , 1998, astro-ph/9806049.

[7]  E. Liang,et al.  Transonic Black Hole Accretion Disks: A Unified Model for Optically Thin and Thick Disks , 1998 .

[8]  C. Shrader,et al.  The High-Energy Spectra of Accreting Black Holes: Observational Evidence for Bulk-Motion Infall , 1998, astro-ph/9803309.

[9]  J. Grove,et al.  Gamma-Ray Spectral States of Galactic Black Hole Candidates , 1998, astro-ph/9802242.

[10]  L. Titarchuk,et al.  Mechanisms for High-frequency QPOs in Neutron Star and Black Hole Binaries , 1997, astro-ph/9712348.

[11]  R. W. Nelson,et al.  Evidence for a Disk-Jet Interaction in the Microquasar GRS 1915+105 , 1997, astro-ph/9710374.

[12]  D. Gruber,et al.  In-Flight Performance of the High Energy X-Ray Timing Experiment on the Rossi X-Ray Timing Explorer , 1997, astro-ph/9710328.

[13]  Lev Titarchuk,et al.  The Extended Power Law as an Intrinsic Signature for a Black Hole , 1997, astro-ph/9708255.

[14]  G. Pooley,et al.  The variable radio emission from GRS 1915 + 105 , 1997, astro-ph/9708171.

[15]  J. Paradijs,et al.  A Unified Model for the Spectral Variability in GRS 1915+105 , 1997, astro-ph/9708113.

[16]  Jochen Greiner,et al.  RXTE Observations of QPOs in the Black Hole Candidate GRS 1915+105 , 1997 .

[17]  M. Begelman,et al.  Self-consistent Thermal Accretion Disk Corona Models for Compact Objects. I. Properties of the Corona and the Spectrum of Escaping Radiation , 1997, The Astrophysical Journal.

[18]  W. Cui,et al.  Black Hole Spin in X-Ray Binaries: Observational Consequences , 1997, astro-ph/9704072.

[19]  A. R. King,et al.  An Unstable Central Disk in the Superluminal Black Hole X-Ray Binary GRS 1915+105 , 1997, astro-ph/9702048.

[20]  L. Titarchuk,et al.  Phase Difference and Coherence as Diagnostics of Accreting Compact Sources , 1997, astro-ph/9703113.

[21]  Edward H. Morgan,et al.  Rossi X-Ray Timing Explorer Observations of GRS 1915+105 , 1996 .

[22]  Jean H. Swank,et al.  The Pattern of Correlated X-Ray Timing and Spectral Behavior in GRS 1915+105 , 1996, astro-ph/9612128.

[23]  Jean H. Swank,et al.  Rapid Bursts from GRS 1915+105 with RXTE , 1996, astro-ph/9706134.

[24]  William W. Zhang,et al.  In-orbit performance and calibration of the Rossi X-ray Timing Explorer (RXTE) Proportional Counter Array (PCA) , 1996, Optics & Photonics.

[25]  J. Orosz,et al.  Optical Observations of GRO J1655–40 in Quiescence. I. A Precise Mass for the Black Hole Primary , 1996, astro-ph/9610211.

[26]  S. Eikenberry,et al.  Time Evolution and the Nature of the Near-Infrared Jets in GRS 1915+105 , 1996, astro-ph/9609181.

[27]  R. Klein,et al.  Quasi-periodic X-Ray Brightness Oscillations of GRO J1744–28 , 1996 .

[28]  R. Sunyaev,et al.  Near-infrared jets in the Galactic microquasar GRS1915+105 , 1996, Nature.

[29]  S. Chakrabarti,et al.  Spectral Properties of Accretion Disks Around Galactic and Extragalactic Black Holes , 1995, astro-ph/9510005.

[30]  S. Chakrabarti,et al.  Resonance Oscillation of Radiative Shock Waves in Accretion Disks around Compact Objects , 1995, astro-ph/9508022.

[31]  F. Takahara,et al.  On the Spectral Hardening Factor of the X-Ray Emission from Accretion Disks in Black Hole Candidates , 1995 .

[32]  R. Taam,et al.  The evolution of accretion disks with coronae: A model for the low-frequency quasi-periodic oscillations in X-ray binaries , 1995, astro-ph/9504074.

[33]  R. Narayan,et al.  Unified description of accretion flows around black holes , 1995, astro-ph/9502015.

[34]  I. Mirabel,et al.  A superluminal source in the Galaxy , 1994, Nature.

[35]  Lev Titarchuk,et al.  GENERALIZED COMPTONIZATION MODELS AND APPLICATION TO THE RECENT HIGH-ENERGY OBSERVATIONS , 1994 .

[36]  N. Khavenson,et al.  LOCALIZATION AND SPECTRUM OF THE X-RAY TRANSIENT SOURCE GRS 1915+105 , 1994 .

[37]  R. Taam,et al.  Low-frequency quasi-periodic oscillations in low-mass X-ray binaries and galactic black hole candidates , 1994, astro-ph/9402011.

[38]  K. Mitsuda,et al.  Application of a general relativistic accretion disk model to LMC X-1, LMC X-3, X1608 - 522, and X1636 - 536 , 1991 .