scholarly journals Stellar wind in state transitions of high-mass X-ray binaries

2015 ◽  
Vol 575 ◽  
pp. A5 ◽  
Author(s):  
J. Čechura ◽  
P. Hadrava
Keyword(s):  
Stellar Wind ◽  
High Mass ◽  
State Transitions ◽  
X Ray ◽  
X Ray Binaries

scholarly journals On the origin of Supergiant Fast X-ray Transients

2018 ◽  
Vol 14 (S346) ◽  
pp. 193-196
Author(s):  
Swetlana Hubrig ◽  
Lara Sidoli ◽  
Konstantin A. Postnov ◽  
Markus Schöller ◽  
Alexander F. Kholtygin ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Neutron Star ◽  
Stellar Wind ◽  
Longitudinal Magnetic Field ◽  
High Mass ◽  
Large Telescope ◽  
X Ray ◽  
Very Large Telescope ◽  
Low X ◽  
X Ray Binaries

Abstract. A fraction of high-mass X-ray binaries are supergiant fast X-ray transients. These systems have on average low X-ray luminosities, but display short flares during which their X-ray luminosity rises by a few orders of magnitude. The leading model for the physics governing this X-ray behaviour suggests that the winds of the donor OB supergiants are magnetized. In agreement with this model, the first spectropolarimetric observations of the SFXT IGR J11215-5952 using the FORS 2 instrument at the Very Large Telescope indicate the presence of a kG longitudinal magnetic field. Based on these results, it seems possible that the key difference between supergiant fast X-ray transients and other high-mass X-ray binaries are the properties of the supergiant’s stellar wind and the physics of the wind’s interaction with the neutron star magnetosphere.

scholarly journals State transitions triggered by inverse magnetic field: probably applied in high-mass X-ray binaries?

2016 ◽  
Vol 16 (3) ◽  
pp. 012
Author(s):  
Shuang-Liang Li ◽  
Zhen Yan
Keyword(s):  
Magnetic Field ◽  
High Mass ◽  
State Transitions ◽  
X Ray ◽  
X Ray Binaries

scholarly journals Color–color diagrams as tools for assessment of the variable absorption in high mass X-ray binaries

2020 ◽  
Vol 643 ◽  
pp. A109
Author(s):  
V. Grinberg ◽  
M. A. Nowak ◽  
N. Hell
Keyword(s):  
Stellar Wind ◽  
Binary Systems ◽  
Compact Object ◽  
Spectral Shape ◽  
High Mass ◽  
Line Of Sight ◽  
Current Generation ◽  
X Ray ◽  
Partial Covering ◽  
X Ray Binaries

High mass X-ray binaries hold the promise of allowing us to understand the structure of the winds of their supermassive companion stars by using the emission from the compact object as a backlight to evaluate the variable absorption in the structured stellar wind. The wind along the line of sight can change on timescales as short as minutes and below. However, such short timescales are not available for the direct measurement of absorption through X-ray spectroscopy with the current generation of X-ray telescopes. In this paper, we demonstrate the usability of color–color diagrams for assessing the variable absorption in wind accreting high mass X-ray binary systems. We employ partial covering models to describe the spectral shape of high mass X-ray binaries and assess the implication of different absorbers and their variability on the shape of color–color tracks. We show that in taking into account, the ionization of the absorber, and in particular accounting for the variation of ionization with absorption depth, is crucial to describe the observed behavior well.

scholarly journals Supergiant fast X-ray transients versus classical supergiant high mass X-ray binaries: Does the difference lie in the companion wind?

2018 ◽  
Vol 610 ◽  
pp. A50 ◽  
Author(s):  
P. Pradhan ◽  
E. Bozzo ◽  
B. Paul
Keyword(s):  
Stellar Wind ◽  
Equivalent Width ◽  
High Mass ◽  
Stellar Winds ◽  
Data Set ◽  
Iron Line ◽  
X Ray ◽  
Eclipse Observations ◽  
The Difference ◽  
X Ray Binaries

We present a comparative study of stellar winds in classical supergiant high mass X-ray binaries (SgXBs) and supergiant fast X-ray transients (SFXTs) based on the analysis of publicly available out-of-eclipse observations performed with Suzaku and XMM-Newton. Our data set includes 55 observations of classical SgXBs and 21 observations of SFXTs. We found that classical SgXBs are characterized by a systematically higher absorption and luminosity compared to the SFXTs, confirming the results of previous works in the literature. Additionally, we show that the equivalent width of the fluorescence Kα iron line in the classical SgXBs is significantly larger than that of the SFXTs (outside X-ray eclipses). Based on our current understanding of the physics of accretion in these systems, we conclude that the most likely explanation of these differences is ascribed to the presence of mechanisms inhibiting accretion most of the time in SFXTs, thereby leading to a much less efficient photoionization of the stellar wind compared to classical SgXBs. We do not find evidence for the previously reported anticorrelation between the equivalent width of the fluorescence iron line and the luminosity of SgXBs.

scholarly journals GLOBAL SIMULATIONS OF THE INTERACTION OF MICROQUASAR JETS WITH A STELLAR WIND IN HIGH-MASS X-RAY BINARIES

2015 ◽  
Vol 801 (1) ◽  
pp. 55 ◽  
Author(s):  
D. Yoon ◽  
S. Heinz
Keyword(s):  
Stellar Wind ◽  
High Mass ◽  
X Ray ◽  
X Ray Binaries

scholarly journals Stellar winds in high-mass X-ray binaries

1995 ◽  
Vol 163 ◽  
pp. 271-279
Author(s):  
Lex Kaper
Keyword(s):  
Stellar Wind ◽  
Large Scale ◽  
Binary Systems ◽  
Compact Object ◽  
High Mass ◽  
X Rays ◽  
Ionization Zone ◽  
X Ray ◽  
Massive Binary Systems ◽  
X Ray Binaries

High-mass X-ray binaries (HMXBs) represent an important stage in the evolution of massive binary systems. The compact object (in most cases an X-ray pulsar) not only provides information on the orbital and stellar parameters, but also probes the stellar wind of the massive companion, an OB supergiant or Be star. The X-ray luminosity directly depends on the density and the velocity of the wind at the orbit of the X-ray source. Important constraints on the stellar-wind structure can be set by studying the orbital modulation of UV P-Cygni profiles. In this paper different aspects of the interactive wind-accretion process are highlighted, such as the highly variable X-ray luminosity, the influence of the X-rays on the radiative acceleration of the wind inside the ionization zone, and the large-scale structures that trail the X-ray source in its orbit.

scholarly journals Wind inhibition by X-ray irradiation in high-mass X-ray binaries

2016 ◽  
Vol 12 (S329) ◽  
pp. 417-417
Author(s):  
Jiří Krtička ◽  
Jiří Kubát ◽  
Iva Krtičková
Keyword(s):  
Optical Depth ◽  
Stellar Wind ◽  
Light Absorption ◽  
Massive Stars ◽  
High Mass ◽  
X Rays ◽  
Radiative Force ◽  
X Ray ◽  
Theoretical Predictions ◽  
X Ray Binaries

AbstractWinds of hot massive stars are driven radiatively by light absorption in the lines of heavier elements. Therefore, the radiative force depends on the wind ionization. That is the reason why the accretion powered X-ray emission of high-mass X-ray binaries influences the radiative force and may even lead to wind inhibition. We model the effect of X-ray irradiation on the stellar wind in high-mass X-ray binaries. The influence of X-rays is given by the X-ray luminosity, by the optical depth between a given point and the X-ray source, and by the distance to the X-ray source. The influence of X-rays is stronger for higher X-ray luminosities and in closer proximity of the X-ray source. There is a forbidden area in the diagrams of X-ray luminosity vs. the optical depth parameter. The observations agree with theoretical predictions, because all wind-powered high-mass X-ray binary primaries lie outside the forbidden area. The positions of real binaries in the diagram indicate that their X-ray luminosities are self-regulated.

scholarly journals Clumped stellar winds in supergiant high-mass X-ray binaries

2012 ◽  
Vol 8 (S290) ◽  
pp. 287-288 ◽  
Author(s):  
L. M. Oskinova ◽  
A. Feldmeier ◽  
P. Kretschmar
Keyword(s):  
Stellar Wind ◽  
Compact Object ◽  
Time Dependent ◽  
High Mass ◽  
Stellar Winds ◽  
Degree Of Ionization ◽  
X Ray ◽  
Wind Theory ◽  
Supergiant Star ◽  
X Ray Binaries

AbstractThe clumping of massive star winds is an established paradigm, which is confirmed by multiple lines of evidence and is supported by stellar wind theory. We use the results from time-dependent hydrodynamical models of the instability in the line-driven wind of a massive supergiant star to derive the time-dependent accretion rate on to a compact object in the Bondi-Hoyle-Lyttleton approximation. The strong density and velocity fluctuations in the wind result in strong variability of the synthetic X-ray light curves. Photoionization of inhomogeneous winds is different from the photoinization of smooth winds. The degree of ionization is affected by the wind clumping. The wind clumping must also be taken into account when comparing the observed and model spectra of the photoionized stellar wind.

scholarly journals Stellar wind accretion and accretion disk formation: Applications to neutron star high-mass X-ray binaries

2019 ◽  
Vol 71 (3) ◽  
Author(s):  
Shigeyuki Karino ◽  
Kenji Nakamura ◽  
Ali Taani
Keyword(s):  
Neutron Star ◽  
Accretion Disk ◽  
Stellar Wind ◽  
High Mass ◽  
X Ray ◽  
Disk Formation ◽  
X Ray Binaries

scholarly journals Wind inhibition by X-ray irradiation in HMXBs: the influence of clumping and the final X-ray luminosity

2018 ◽  
Vol 620 ◽  
pp. A150 ◽  
Author(s):  
J. Krtička ◽  
J. Kubát ◽  
I. Krtičková
Keyword(s):  
Mass Loss ◽  
Stellar Wind ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
Terminal Velocity ◽  
High Mass ◽  
Small Scale ◽  
X Rays ◽  
X Ray ◽  
X Ray Binaries

Context. In wind-powered X-ray binaries, the radiatively driven stellar wind from the primary may be inhibited by the X-ray irradiation. This creates the feedback that limits the X-ray luminosity of the compact secondary. Wind inhibition might be weakened by the effect of small-scale wind inhomogeneities (clumping) possibly affecting the limiting X-ray luminosity. Aims. We study the influence of X-ray irradiation on the stellar wind for different radial distributions of clumping. Methods. We calculate hot star wind models with external irradiation and clumping using our global wind code. The models are calculated for different parameters of the binary. We determine the parameters for which the X-ray wind ionization is so strong that it leads to a decrease of the radiative force. This causes a decrease of the wind velocity and even of the mass-loss rate in the case of extreme X-ray irradiation. Results. Clumping weakens the effect of X-ray irradiation because it favours recombination and leads to an increase of the wind mass-loss rate. The best match between the models and observed properties of high-mass X-ray binaries (HMXBs) is derived with radially variable clumping. We describe the influence of X-ray irradiation on the terminal velocity and on the mass-loss rate in a parametric way. The X-ray luminosities predicted within the Bondi-Hoyle-Lyttleton theory agree nicely with observations when accounting for X-ray irradiation. Conclusions. The ionizing feedback regulates the accretion onto the compact companion resulting in a relatively stable X-ray source. The wind-powered accretion model can account for large luminosities in HMXBs only when introducing the ionizing feedback. There are two possible states following from the dependence of X-ray luminosity on the wind terminal velocity and mass-loss rate. One state has low X-ray luminosity and a nearly undisturbed wind, and the second state has high X-ray luminosity and exhibits a strong influence of X-rays on the flow.

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