The evolution of the disc variability along the hard state of the black hole transient GX 339-4

Abstract

We report on the analysis of hard-state power spectral density function (PSD) of GX 339-4 down to the soft X-ray band, where the disc significantly contributes to the total emission. At any luminosity probed, the disc in the hard state is intrinsically more variable than in the soft state. However, the fast decrease of disc variability as a function of luminosity, combined with the increase of disc intensity, causes a net drop of fractional variability at high luminosities and low energies, which reminds the well-known behaviour of disc-dominated energy bands in the soft state. The peak-frequency of the high-frequency Lorentzian (likely corresponding to the high-frequency break seen in active galactic nuclei, AGN) scales with luminosity, but we do not find evidence for a linear scaling. In addition, we observe that this characteristic frequency is energy-dependent. We find that the normalization of the PSD at the peak of the high-frequency Lorentzian decreases with luminosity at all energies, though in the soft band this trend is steeper. Together with the frequency shift, this yields quasi-constant high frequency (5-20 Hz) fractional rms at high energies, with less than 10 percent scatter. This reinforces previous claims suggesting that the high frequency PSD solely scales with BH mass. On the other hand, this constancy breaks down in the soft band (where the scatter increases to ~30 percent). This is a consequence of the additional contribution from the disc component, and resembles the behaviour of optical variability in AGN.

12 pages, 8 figures, accepted for publication in MNRAS

References in corpus (9)

• X-ray Properties of Black-Hole Binaries
• Modelling the behaviour of accretion flows in X-ray binaries
• X-ray reverberation around accreting black holes
• On the masses and evolutionary status of the black hole binary GX 339-4. A twin system of XTE J1550-564?
• The variability plane of accreting compact objects
• Broadband X-ray Spectra of GX 339-4 and the Geometry of Accreting Black Holes in the Hard State
• A new cosmological distance measure using AGN X-ray variability
• High-frequency X-ray variability as a mass estimator of stellar and supermassive black holes
• Swift X-ray Telescope study of the Black Hole Binary MAXI J1659-152: Variability from a two component accretion flow

Cited by in corpus (23)

• A powerful flare from Sgr A* confirms the synchrotron nature of the X-ray emission
• Pan-STARRS1 variability of XMM-COSMOS AGN. II. Physical correlations and power spectrum analysis
• Accretion disks and coronae in the X-ray flashlight
• X-ray quasi-periodic oscillations in Lense--Thirring precession model - I. variability of relativistic continuum
• The reverberation lag in the low mass X-ray binary H1743-322
• A spectrally stratified hot accretion flow in the hard state of MAXI J1820+070
• Suzaku spectroscopy of the neutron star transient 4U 1608-52 during its outburst decay
• Interference as an origin of the peaked noise in accreting X-ray binaries
• Looking for the underlying cause of black hole X-ray variability in GRMHD simulations
• Swift J174540.7-290015: a new accreting binary in the Galactic Center
• Accretion geometry of the black hole binary MAXI J1820+070 probed by frequency-resolved spectroscopy
• Dark jets in the soft X-ray state of black hole binaries?
• Rapid X-ray variability properties during the unusual very hard state in neutron-star low-mass X-ray binaries
• Detection of periodic signals in AGN red noise light curves: empirical tests on the Auto-Correlation Function and Phase Dispersion Minimization
• A broadband spectral-timing study of QPOs in the bright black hole X-ray binary Swift J1727.8-1613
• Multi-wavelength spectroscopy of the black hole candidate MAXI J1813-095 during its discovery outburst
• The very faint hard state of the persistent neutron star X-ray binary SLX 1737-282 near the Galactic centre
• Observations of X-ray reverberation around black holes
• The inner flow geometry in MAXI J1820+070 during hard and hard-intermediate states
• A rapid optical and X-ray timing study of the neutron star X-ray binary Swift J1858.6-0814
• Probing black-hole accretion through time variability
• Modeling the upper kHz QPOs of 4U 1728-34 with X-ray reverberation
• Tracing the reverberation lag in the hard state of black hole X-ray binaries