Simultaneous Measurements of X-Ray Luminosity and Kilohertz Quasi-Periodic Oscillations in Low-Mass X-Ray Binaries

Abstract

We measure simultaneously the properties of the energy spectra and the frequencies of the kilohertz quasi-periodic oscillations (QPOs) in fifteen low mass X-ray binaries covering a wide range of X-ray luminosities. In each source the QPO frequencies cover the same range of approximately 300 Hz to 1300 Hz, though the sources differ by two orders of magnitude in their X-ray luminosities (as measured from the unabsorbed 2-50 keV flux). So the X-ray luminosity does not uniquely determine the QPO frequency. This is difficult to understand since the evidence from individual sources indicates that the frequency and luminosity are very well correlated at least over short timescales. Perhaps beaming effects or bolometric corrections change the observed luminosities, or perhaps part of the energy in mass accretion is used to power outflows reducing the energy emitted in X-rays. It is also possible that the parameters of a QPO model are tuned in such a way that the same range of frequencies appears in all sources. Different modes of accretion may be involved for example (disk and radial) or multiple parameters may conspire to yield the same frequencies.

14 pages, 2 figures (1 in color), accepted by ApJ, see the 'QPO page': http://www.astro.uva.nl/~ecford/qpos.html

References in corpus (9)

• The radio luminosity of persistent X-ray binaries
• Precise Measurements of the Kilohertz Quasi-Periodic Oscillations in 4U 1728-34
• The power spectral properties of the Z-source GX 340+0
• Strong Field Gravity and X-Ray Observations of 4U1820-30
• Correlated Timing and Spectral Variations of the Soft X-ray Transient Aquila X-1: Evidence for an Atoll classification
• XTE J2123-058: A New Neutron Star X-Ray Transient
• Interpretation of 35 Hz QPO in the Atoll Source 4U 1702-42 as a Low Branch of the Keplerian Oscillations Under the Influence of the Coriolis Force
• Relativistic Jets from X-ray binaries
• Low and High Frequency Quasi-Periodic Oscillations in 4U1915-05

Cited by in corpus (55)

• Correlated X-ray Spectral and Timing Behavior of the Black Hole Candidate XTE J1550-564: A New Interpretation of Black Hole States
• Detecting gravitational wave emission from the known accreting neutron stars
• Multi-resonance orbital model of high-frequency quasi-periodic oscillations: possible high-precision determination of black hole and neutron star spin
• A multi-Lorentzian timing study of the atoll sources 4U 0614+09 and 4U 1728-34
• XTE J1701-462 and its Implications for the Nature of Subclasses in Low-Magnetic-Field Neutron Star Low-Mass X-Ray Binaries
• A Possible Explanation for the "Parallel Tracks" Phenomenon in Low-Mass X-Ray Binaries
• How Do Z and Atoll X-ray Binaries Differ?
• RXTE observations of the first transient Z source XTE J1701-462: shedding new light on mass accretion in luminous neutron star LMXBs
• X-ray time variability across the atoll source states of 4U 1636--53
• The broad band X-ray/hard X-ray spectra of accreting neutron stars
• The variability plane of accreting compact objects
• Average hard X-ray emission from NS LMXBs: Observational evidence of different spectral states in NS LMXBs
• The Amplitude of the Kilohertz Quasi-periodic Oscillations in 4U 1728-34, 4U 1608-52, and Aql X-1, as a Function of X-ray Intensity
• Phase-resolved X-ray spectroscopy of the millisecond pulsar SAX J1808.4-3658
• Modelling the spin equilibrium of neutron stars in LMXBs without gravitational radiation
• Relations Between Timing Features and Colors in Accreting Millisecond Pulsars
• Millisecond Oscillations and Photospheric Radius Expansion in Thermonuclear X-Ray Bursts
• Disc-jet coupling in an atoll-type neutron star X-ray binary: 4U 1728-34 (GX 354-0)
• What ignites on the neutron star of 4U 0614+091?
• Low and high frequency variability as a function of spectral properties in the bright X-ray binary GX 5-1
• On the maximum amplitude and coherence of the kilohertz quasi-periodic oscillations in low-mass X-ray binaries
• Is there a link between the neutron-star spin and the frequency of the kilohertz quasi-periodic oscillations?
• On the Correlated Spectral and Timing Properties of 4U 1636-53: an Atoll Source at High Accretion Rates
• NuSTAR Observations of the State Transition of Millisecond Pulsar Binary PSR J1023+0038
• Surface Modes on Bursting Neutron Stars and X-ray Burst Oscillations
• On the distribution of frequency ratios of kHz QPOs
• Peculiar spectral and power spectral behaviour of the LMXB GX 13+1
• Correlation between radio luminosity and X-ray timing frequencies in neutron star and black hole X-ray binaries
• GX~3+1: the stability of spectral index as a function of mass accretion rate
• Investigation of the emission radii of kHz QPOs for the accreting millisecond X-Ray pulsars, Atoll and Z sources
• Stability of the photon indices in Z-source GX 340+0 for spectral states
• Spectral state evolution of 4U~1820-30: the stability of the spectral index of Comptonization tail
• X-Ray Spectra of The High-Mass X-RAY Binary 4U~1700-37 using BeppoSAX, Suzaku and RXTE Observations
• Iron-line and continuum variations in the XMM-Newton and Suzaku spectra of the neutron-star low-mass X-ray binary 4U 1636-53
• The time derivative of the kilohertz quasi-periodic oscillations in 4U 1636-53
• Timing and spectral properties of the accreting millisecond pulsar SWIFT J1756.9-2508
• Constraining the size of the Comptonizing medium by modeling the energy dependent time-lags of kHz QPOs of Neutron star system
• On the Disappearance of Kilohertz Quasi-Periodic Oscillations at a High Mass Accretion Rate in Low-Mass X-ray Binaries
• Discovery of kilohertz quasi-periodic oscillations and state transitions in the low-mass X-ray binary 1E~1724-3045 (Terzan 2)
• Relation between the properties of the kilohertz quasi-periodic oscillations and spectral parameters in 4U 1636$-$53
• Evolution of cross-correlation and time lag of 4U 1735-44 along the branches
• BEPPOSAX and RXTE spectral study of the low-mass X-ray binary 4u~1705-44. Spectral hardening during the banana branch
• Galactic Black HOle Binary Systems
• The properties of cross-correlation and spectra of the low-mass X-ray binary 4U 1608-52
• Correlations between the frequencies of twin kHz QPOs and spins of neutron stars in LMXBs
• Simultaneous observations of a pair of kilohertz QPOs and a plausible 1860 Hz QPO from an accreting neutron star system
• Parallel tracks as quasi-steady states for the magnetic boundary layers in neutron-star low-mass X-ray binaries
• The kHz QPOs as a probe of the X-ray color-color diagram and accretion-disk structure for the atoll source 4U 1728-34
• Magnetized SASI: its mechanism and possible connection to some QPOs in XRBs
• Discovery of twin kHz quasi periodic oscillations in the low mass X-ray binary XTE J1701-407
• A new correlation with lower kilohertz quasi-periodic oscillation frequency in the ensemble of low-mass X-ray binaries
• Probing the accretion disc structure by the twin kHz QPOs and spins of neutron stars in LMXBs
• Kilohertz quasi-periodic oscillations in neutron-star X-ray binaries: Flattening of the lag spectrum with increasing luminosity
• Investigating the coronal structure by studying time lags in the Atoll source 4U 1705-44 using AstroSat
• A possible explanation of the parallel tracks in kilohertz quasi-periodic oscillations from low-mass-X-ray binaries