The clumpy absorber in the high-mass X-ray binary Vela X-1

Abstract

Bright and eclipsing, the high-mass X-ray binary Vela X-1 offers a unique opportunity to study accretion onto a neutron star from clumpy winds of O/B stars and to disentangle the complex accretion geometry of these systems. In Chandra-HETGS spectroscopy at orbital phase ~0.25, when our line of sight towards the source does not pass through the large-scale accretion structure such as the accretion wake, we observe changes in overall spectral shape on timescales of a few kiloseconds. This spectral variability is, at least in part, caused by changes in overall absorption and we show that such strongly variable absorption cannot be caused by unperturbed clumpy winds of O/B stars. We detect line features from high and low ionization species of silicon, magnesium and neon whose strengths and presence depend on the overall level of absorption. They imply a co-existence of cool and hot gas phases in the system that we interpret as a highly variable, structured accretion flow close to the compact object such as has been recently seen in simulations of wind accretion in high-mass X-ray binaries.

17 pages, 14 figures; A&A accepted

References in corpus (59)

• On the Absorption of X-rays in the Interstellar Medium
• Atomic Data for Astrophysics. II. New Analytic Fits for Photoionization Cross Sections of Atoms and Ions
• A Grid of NLTE Line-Blanketed Model Atmospheres of Early B-type Stars
• Studies in Astronomical Time Series Analysis. VI. Bayesian Block Representations
• Updated Atomic Data and Calculations for X-ray Spectroscopy
• Non-linear X-ray variability in X-ray binaries and active galaxies
• The Chandra High Energy Transmission Grating: Design, Fabrication, Ground Calibration and Five Years in Flight
• Photoionization Modeling and the K Lines of Iron
• X-ray photoionized plasma diagnostics with Helium-like ions. Application to Warm Absorber-Emitter in Active Galactic Nuclei
• XMM-Newton Reflection Grating Spectrometer Observations of Discrete Soft-X-ray Emission Features from NGC 1068
• Thermal and Bulk Comptonization in Accretion-Powered X-Ray Pulsars
• Theory of quasi-spherical accretion in X-ray pulsars
• Line ratios for Helium-like ions: Applications to collision-dominated plasmas
• Origin of the Soft Excess in X-ray Pulsars
• The mass of the neutron star in Vela X-1 and tidally induced non-radial oscillations in GP Vel
• High resolution X-Ray spectroscopy of Zeta Puppis with the XMM-Newton Reflection Grating Spectrometer
• The Chandra High Energy Transmission Grating Observation of an X-ray Ionization Cone in Markarian 3
• X-ray Spectral Study of the Photoionized Stellar Wind in Vela~X-1
• Towards a unified view of inhomogeneous stellar winds in isolated supergiant stars and supergiant high mass X-ray binaries
• Modeling of iron K lines: radiative and Auger decay data for Fe II-Fe IX
• High variability in Vela X-1: giant flares and off states
• NuSTAR discovery of a luminosity dependent cyclotron line energy in Vela X-1
• The X-Ray Spectrum and Global Structure of the Stellar Wind in Vela X-1
• A Chandra survey of fluorescence Fe lines in X-ray Binaries at high resolution
• Clumping in the inner winds of hot, massive stars from hydrodynamical line-driven instability simulations
• Coupling hydrodynamics with comoving frame radiative transfer: I. A unified approach for OB and WR stars
• Chandra X-ray spectroscopy of the focused wind in the Cygnus X-1 system. I. The non-dip spectrum in the low/hard state
• Clumped stellar winds in supergiant high-mass X-ray binaries: X-ray variability and photoionization
• 2D wind clumping in hot, massive stars from hydrodynamical line-driven instability simulations using a pseudo-planar approach
• Inner-shell 1s - 2p Soft X-ray Absorption Lines
• Pulse phase resolved analysis of the HMXB Cen X-3 over two binary orbits
• X-ray variation statistics and wind clumping in Vela X-1
• No anti-correlation between cyclotron line energy and X-ray flux in 4U 0115+634
• The Ionized Stellar Wind in Vela X-1 During Eclipse
• Measurements and analysis of helium-like triplet ratios in the X-ray spectra of O-type stars
• An XMM-Newton view of FeKα in HMXBs
• A new model for the X-ray continuum of the magnetized accreting pulsars
• Measuring the stellar wind parameters in IGR J17544-2619 and Vela X-1 constrains the accretion physics in Supergiant Fast X-ray Transient and classical Supergiant X-ray Binaries
• Long term variability of Cygnus X-1: VII. Orbital variability of the focussed wind in Cyg X-1 / HDE 226868 system
• Modelling the orbital modulation of ultraviolet resonance lines in high-mass X-ray binaries
• On the nature of `off' states in slowly rotating low-luminosity X-ray pulsars
• Chandra X-ray spectroscopy of the very early O supergiant HD 93129A: constraints on wind shocks and the mass-loss rate
• Chandra X-Ray Spectroscopy of the Focused Wind in the Cygnus X-1 System. II. The Nondip Spectrum in the Low/Hard State - Modulations with Orbital Phase
• The NuSTAR X-ray Spectrum of Hercules X-1: A Radiation-Dominated Radiative Shock
• Origin of the X-ray off-states in Vela X-1
• The accretion environment in Vela X-1 during a flaring period using XMM-Newton
• Short-Term Variability of X-rays from Accreting Neutron Star Vela X-1: I. Suzaku Observations
• Laboratory Measurements of the K-shell transition energies in L-shell ions of Si and S
• Variation in Emission and Absorption Lines and Continuum Flux by Orbital Phase in Vela X-1
• X-ray photoionized bubble in the wind of Vela X-1 pulsar supergiant companion
• Shock generated vorticity in the interstellar medium and the origin of the stellar initial mass function
• Probing the stellar wind environment of Vela X-1 with MAXI
• Footprints in the wind of Vela X-1 traced with MAXI
• Beyond XSPEC: Towards Highly Configurable Analysis
• Probing large-scale wind structures in Vela X-1 using off-states with INTEGRAL
• A numerical investigation of wind accretion in persistent Supergiant X-ray Binaries I - Structure of the flow at the orbital scale
• Short-Term Variability of X-rays from Accreting Neutron Star Vela X-1: II. Monte-Carlo Modeling
• Line absorption of He-like triplet lines by Li-like ions. Caveats of using line ratios of triplets for plasma diagnostics
• The Physics of Wind-Fed Accretion

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• The high energy universe at ultra-high resolution: the power and promise of X-ray interferometry
• Continuum, cyclotron line, and absorption variability in the high-mass X-ray binary Vela X-1
• High-resolution X-ray spectroscopy of the stellar wind in Vela X-1 during a flare
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• Looking through the photoionisation wake: Vela X-1 at ${\phi }_{\mathrm{orb}}\approx 0.75$ with Chandra/HETG
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• Variations of cyclotron resonant scattering features in Vela X-1 revealed with Insight-HXMT
• Color-color diagrams as tools for assessment of the variable absorption in high mass X-ray binaries
• Probing the non-thermal physics of stellar bow shocks using radio observations
• The $\text{False Widow}$ Link Between Neutron Star X-ray Binaries and Spider Pulsars
• The X-ray spectral-timing contribution of the stellar wind in the hard state of Cyg X-1
• X-Ray Views of Galactic Accreting Pulsars in High-Mass X-Ray Binaries
• Variable structures in the stellar wind of the HMXB Vela X-1
• R-matrix electron-impact excitation data for the O-like iso-electronic sequence
• First look at Vela X-1 with XRISM: A simultaneous campaign with XMM-Newton and NuSTAR
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• Clumpy wind studies and the non-detection of cyclotron line in OAO 1657-415
• Variability in high-mass X-ray binaries
• Cyclotron Line Variability and Accretion Dynamics in Vela X-1
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