A broadband spectral-timing study of QPOs in the bright black hole X-ray binary Swift J1727.8-1613

Abstract

Swift J1727.8-1613 went into outburst in August 2023 and was one of the brightest black hole X-ray binaries (BHXRBs) in recent years, leading to extensive observing campaigns by NICER and Insight-HXMT. The source exhibited strong X-ray variability and showed type-C quasi-periodic oscillations (QPOs) on a wide range of frequencies. The high data quality over a broad range of X-ray energies (0.5-150 keV) enables us to study the energy-dependence of the QPO waveform and the phase lags at the QPO fundamental and second harmonic frequencies. Using the biphase, we find that the QPO waveform is strongly energy-dependent, with energy bands below and above 15-20 keV showing opposite waveform evolution. We interpret the energy-dependence of the waveform as being due to a pivoting spectral component at the second harmonic frequency, with a pivot energy around 15-20 keV. Using the cross-spectrum, we find that the phase lags between energy bands above 7 keV at the QPO fundamental are small, while those at the harmonic frequency are dominated by a separate lag component that extends over a broader range of frequencies and relates to the broadband noise variability. Comparing the energy-dependent results obtained with the bispectrum and the cross-spectrum, we show that these two Fourier products extract different variability components, e.g. the QPO and the broadband noise, at the same frequencies. Finally, we compare Swift J1727.8-1613 to BHXRB MAXI J1535-571 and find that their spectral-timing properties are similar, indicating that these QPO properties may represent a subset of sources.

arXiv comment18 pages, 21 figures, 1 table, accepted for publication in MNRAS

References in corpus (76)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Array Programming with NumPy
• Astropy: A Community Python Package for Astronomy
• The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package
• The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package
• Modelling the behaviour of accretion flows in X-ray binaries
• Going with the flow: can the base of jets subsume the role of compact accretion disk coronae?
• RXTE Observation of Cygnus X-1: II. Timing Analysis
• X-ray reverberation around accreting black holes
• Non-linear X-ray variability in X-ray binaries and active galaxies
• Low frequency QPO spectra and Lense-Thirring precession
• Investigating a Fluctuating-accretion Model for the Spectral-timing Properties of Accreting Black Hole Systems
• On the X-ray time lags in the black hole candidates
• A review of quasi-periodic oscillations from black hole X-ray binaries: observation and theory
• Soft state of Cygnus X-1: stable disk and unstable corona
• The corona contracts in a black-hole transient
• X-Ray Variability Coherence: How to Compute it, What it Means, and How it Constrains Models of Cyg X-1 and GX 339-4
• A study of the low-frequency quasi-periodic oscillations in the X-ray light curves of the black hole candidate XTE J1859+226
• A physical model for the continuum variability and QPO in accreting black holes
• The causal connection between disc and power-law variability in hard state black hole X-ray binaries
• Geometrical constraints on the origin of timing signals from black holes
• A unified accretion-ejection paradigm for Black Hole X-ray Binaries
• Discovery of oscillations above 200 keV in a black hole X-ray binary with Insight-HXMT
• Hot accretion flow in black hole binaries: a link connecting X-rays to the infrared
• Inclination dependence of QPO phase lags in black hole X-ray binaries
• No Time for Dead Time: Timing analysis of bright black hole binaries with NuSTAR
• A public relativistic transfer function model for X-ray reverberation mapping of accreting black holes
• Coupling between the accreting corona and the relativistic jet in the micro quasar GRS 1915+105
• vKompth: A variable Comptonisation model for low-frequency quasi-periodic oscillations in black-hole X-ray binaries
• Insight-HXMT observations of jet-like corona in a black hole X-ray binary MAXI J1820+070
• Tomographic reflection modelling of quasi-periodic oscillations in the black hole binary H 1743-322
• Doughnut strikes sandwich: the geometry of hot medium in accreting black hole X-ray binaries
• Reflection Spectra of the Black Hole Binary Candidate MAXI J1535-571 in the Hard State Observed by NuSTAR
• A unified Lense-Thirring precession model for optical and X-ray quasi-periodic oscillations in black hole binaries
• Phase-resolved spectroscopy of low frequency quasi-periodic oscillations in GRS 1915+105
• A NICER Spectrum of MAXI J1535-571: Near-Maximal Black Hole Spin and Potential Disk Warping
• A jet model for Galactic black-hole X-ray sources: Some constraining correlations
• Phase-Resolved Spectroscopy of Type B Quasi-Periodic Oscillations in GX 339-4
• The NICER "Reverberation Machine": A Systematic Study of Time Lags in Black Hole X-Ray Binaries
• Energy and time-lag spectra of black-hole systems in the low state
• Accretion-ejection instability and QPO in black-hole binaries.II. Relativistic effects
• Phase-resolved spectroscopy of a quasi-periodic oscillation in the black hole X-ray binary GRS 1915+105 with NICER and NuSTAR
• Probing the origin of quasi-periodic oscillations: the short-timescale evolution of phase lags in GRS 1915+105
• Phase Lag and Coherence Function of X-ray emission from Black Hole Candidate XTE J1550-564
• X-ray quasi-periodic oscillations in Lense--Thirring precession model - I. variability of relativistic continuum
• The evolution of the corona in MAXI J1535-571 through type-C quasi-periodic oscillations with Insight-HXMT
• The evolving properties of the corona of GRS 1915+105: A spectral-timing perspective through variable-Comptonisation modelling
• Dramatic Drop in the X-Ray Polarization of Swift J1727.8$-$1613 in the Soft Spectral State
• NICER, NuSTAR and Insight-HXMT views to the newly discovered black hole X-ray binary Swift J1727.8--1613
• Observations of a black hole X-ray binary indicate formation of a magnetically arrested disk
• Modelling correlated variability in accreting black holes: the effect of high density and variable ionisation on reverberation lags
• An imperfect double: probing the physical origin of the low-frequency QPO and its harmonic in black hole binaries
• A study of natural frequencies in a dynamic corona-disk system
• The evolution of the broadband temporal features observed in the black-hole transient MAXI J1820+070 with Insight-HXMT
• X-ray time lags from a pivoting power law in black holes
• Dynamical confirmation of a black hole in the X-ray transient Swift J1727.8-1613
• Recovery of the X-ray polarisation of Swift J1727.8$-$1613 after the soft-to-hard spectral transition
• MAXI J1820+070 X-ray spectral-timing reveals the nature of the accretion flow in black hole binaries
• The biphase explained: understanding the asymmetries in coupled Fourier components of astronomical timeseries
• The evolution of the disc variability along the hard state of the black hole transient GX 339-4
• A systematic study of the phase difference between QPO harmonics in black hole X-ray binaries
• Discovery and state transitions of the new Galactic black hole candidate MAXI J1535-571
• X-ray quasi-periodic oscillations in Lense-Thirring precession model -- II. variability of relativistic iron K$\alpha$ line
• Are Low-Frequency Quasi-Periodic Oscillations seen in accretion flows the disk response to a jet instability?
• Alternating lags of QPO harmonics : A Generic model and its application to the 67 millihertz QPO of GRS 1915+105
• A Phase-resolved View of the Low-frequency Quasiperiodic Oscillations from the Black Hole Binary MAXI J1820+070
• Iron Line Variability of Discoseismic Corrugation Modes
• On the nature of QPO phase lags in black hole candidates
• A Likely Inclination Dependence in the Non-linear Variability of Quasi Periodic Oscillations from Black Hole Binaries
• The X-ray corona in the black-hole binary GRO J1655--40 from the properties of non-harmonically related quasi-periodic oscillations
• Determination of QPO properties in the presence of strong broad-band noise: a case study on the data of MAXI J1820+070
• Nonlinear Variability of Quasi-Periodic Oscillations in GX 339-4
• The Broadband X-ray Spectral Properties during the Rising Phases of the Outburst of the New Black Hole X-ray Binary Candidate Swift J1727.8-1613
• The spectral-timing analysis of Cygnus X-1 with Insight-HXMT
• Evidence for a dynamic corona in the short-term time lags of black hole X-ray binary MAXI J1820+070
• The role of outflows in black-hole X-ray binaries

Cited by in corpus (2)

• Black-hole X-ray binary Swift J1727.8$-$1613 shows simultaneous Type-B and Type-C quasi-periodic oscillations across the hard-intermediate and soft-intermediate states
• Search for the Highest-energy Quasiperiodic Oscillation in the Black Hole X-Ray Binary Candidate Swift J1727.8-1613