Accretion disc by Roche lobe overflow in the supergiant fast X-ray transient IGR J08408-4503

Abstract

Supergiant fast X-ray transients (SFXTs) are X-ray binary systems with a supergiant companion and likely a neutron star, which show a fast ($\sim 10^3$ s) and high variability with a dynamic range up to $10^{5-6}$. Given their extreme properties, they are considered among the most valuable laboratories to test accretion models. Recently, the orbital parameters of a member of this class, IGR J08408-4503, were obtained from optical observations. We used this information, together with X-ray observations from previous publications and new results from X-ray and optical data collected by INTEGRAL and presented in this work, to study the accretion mechanisms at work in IGR J08408-4503. We found that the high eccentricity of the compact object orbit and the large size of the donor star imply Roche lobe overflow (RLO) around the periastron. It is also likely that a fraction of the outer layers of the photosphere of the donor star are lost from the Lagrangian point $L_2$ during the periastron passages. On the basis of these findings, we discuss the flaring variability of IGR J08408-4503 assuming the presence of an accretion disc. We point out that IGR J08408-4503 may not be the only SFXT with an accretion disc fueled by RLO. These findings open a new scenario for accretion mechanisms in SFXTs, since most of them have so far been based on the assumption of spherically symmetric accretion.

arXiv commentAccepted for publication in Astronomy & Astrophysics

References in corpus (34)

• The USNO-B Catalog
• Estimating distances from parallaxes IV: Distances to 1.33 billion stars in Gaia Data Release 2
• A new calibration of stellar parameters of Galactic O stars
• ISGRI: the INTEGRAL Soft Gamma-Ray Imager
• The Relation Between Optical Extinction and Hydrogen Column Density in the Galaxy
• The Galactic O-Star Spectroscopic Survey (GOSSS). II. Bright Southern Stars
• Physical Parameters and Wind Properties of Galactic Early B Supergiants
• Are There Magnetars in High Mass X-ray Binaries? The Case of SuperGiant Fast X-Ray Transients
• Chandra observation of the fast X-ray transient IGR J17544-2619: evidence for a neutron star?
• Quantitative studies of the optical and UV spectra of Galactic early B supergiants I. Fundamental parameters
• Spectroscopic and physical parameters of Galactic O-type stars. III. Mass discrepancy and rotational mixing
• The structure of blue supergiant winds and the accretion in supergiant High Mass X-ray Binaries
• Unveiling the nature of six HMXBs through IR spectroscopy
• Bright Flares in Supergiant Fast X-ray Transients
• INTEGRAL results on Supergiant Fast X-ray Transients and accretion mechanism interpretation: ionization effect and formation of transient accretion disks
• Infrared identification of high-mass X-ray binaries discovered by INTEGRAL
• The 100-month Swift catalogue of supergiant fast X-ray transients I. BAT on-board and transient monitor flares
• Multiple flaring activity in the supergiant fast X-ray transient IGR J08408-4503 observed with Swift
• Hard X-ray flares in IGR J08408-4503 unveil clumpy stellar winds
• Magnetic fields of neutron stars in X-ray binaries
• Monitoring Supergiant Fast X-ray Transients with Swift. Results from the first year
• An Extended and More Sensitive Search for Periodicities in RXTE/ASM X-ray Light Curves
• Discovery of a short orbital period in the Supergiant Fast X-ray Transient IGR J16479-4514
• Cumulative luminosity distributions of Supergiant Fast X-ray Transients in hard X-rays
• Supergiant Fast X-ray Transients in outburst: new Swift observations of XTEJ1739-302, IGRJ17544-2619, and IGRJ08408-4503
• The supergiant fast X-ray transients XTE J1739-302 and IGR J08408-4503 in quiescence with XMM-Newton
• INTEGRAL and XMM-Newton observations of IGR J16418-4532: evidence of accretion regime transitions in a supergiant fast X-ray transient
• Seven Years with the Swift Supergiant Fast X-ray Transients Project
• The XMM-Newton view of Supergiant Fast X-ray Transients: the case of IGRJ16418-4532
• A Suzaku X-ray observation of one orbit of the supergiant fast X-ray transient IGR J16479-4514
• The eccentric short-period orbit of the supergiant fast X-ray transient HD 74194 (=LM Vel)
• IGR J08408--4503: a new recurrent Supergiant Fast X-ray Transient
• The longest observation of a low intensity state from a Supergiant Fast X-ray Transient: Suzaku observes IGRJ08408-4503
• Constraining duty cycles through a Bayesian technique

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• A catalogue of high-mass X-ray binaries in the Galaxy: from the INTEGRAL to the Gaia era
• Advances in Understanding High-Mass X-ray Binaries with INTEGRAL and Future Directions
• Blasts from the Past: Supernova Shock Breakouts among X-Ray Transients in the XMM-Newton Archive
• The stellar and wind parameters of six prototypical HMXBs and their evolutionary status
• A semi-analytical treatment to wind accretion in neutron star supergiant high mass X-ray binaries: I. eccentric orbits
• Detecting the intrinsic X-ray emission from the O-type donor star and the residual accretion in a Supergiant Fast X-ray Transient during its faintest state
• Deciphering Accretion-Driven Starquakes in Recycled Millisecond Pulsars using Gravitational Waves