On the nature of QPO phase lags in black hole candidates

Abstract

Observations of quasi-periodic oscillations (QPOs) in X-ray binaries hold a key to understanding many aspects of these enigmatic systems. Complex appearance of the Fourier phase lags related to QPOs is one of the most puzzling observational effects in accreting black holes. In this Letter we show that QPO properties, including phase lags, can be explained in a framework of a simple scenario, where the oscillating media provides a feedback on the emerging spectrum. We demonstrate that the QPO waveform is presented by the product of a perturbation and a time delayed response factors, where the response is energy dependent. The essential property of this effect is its non-linear and multiplicative nature. Our multiplicative reverberation model successfully describes the QPO components in energy dependent power spectra as well as the appearance of the phase lags between signal in different energy bands. We apply our model to QPOs observed by Rossi X-ray Timing Explorer in BH candidate XTE J1550-564. We briefly discuss the implications of the observed energy dependence of the QPO reverberation times and amplitudes to the nature of the power law spectral component and its variability.

arXiv comment5 pages, 4 figures, ApJ Letters, accepted for publication

Cited by in corpus (14)

• A two-component Comptonisation model for the type-B QPO in MAXI J1348-630
• Phase-resolved spectroscopy of low frequency quasi-periodic oscillations in GRS 1915+105
• Detection of the first infra-red quasi periodic oscillation in a black hole X-ray binary
• Time lags of the type-B QPO in MAXI J1348-630
• The evolving properties of the corona of GRS 1915+105: A spectral-timing perspective through variable-Comptonisation modelling
• Variability and phase lags of the type-C quasi-periodic oscillation of MAXI J1348-630 with NICER
• The biphase explained: understanding the asymmetries in coupled Fourier components of astronomical timeseries
• Alternating lags of QPO harmonics : A Generic model and its application to the 67 millihertz QPO of GRS 1915+105
• A broadband spectral-timing study of QPOs in the bright black hole X-ray binary Swift J1727.8-1613
• The X-ray corona in the black-hole binary GRO J1655--40 from the properties of non-harmonically related quasi-periodic oscillations
• A timing view of the heartbeat state of GRS 1915+105
• Are spectral and timing correlations similar in different spectral states in black hole X-ray binaries?
• Detection of QPO Soft Lag during Outburst of Swift J1727.8-1613: Estimation of Instrinsic Parameters from Spectral Study
• A NuSTAR study of quasi-periodic oscillations from the ultraluminous X-ray sources in M82