scholarly journals FORMATION AND DESTRUCTION OF JETS IN X-RAY BINARIES

2012 ◽  
Vol 08 ◽  
pp. 287-292
Author(s):  
IOANNIS CONTOPOULOS ◽  
NIKOLAOS D. KYLAFIS ◽  
DEMOSTHENES KAZANAS ◽  
DIMITRIS M. CHRISTODOULOU
Keyword(s):  
Physical Mechanism ◽  
Compact Object ◽  
Physical Explanation ◽  
X Ray ◽  
Radio Jets ◽  
History Of ◽  
X Ray Binaries ◽  
Spectral States ◽  
Spectral State ◽  
Natural Way

Neutron-star and black hole X-ray binaries (XRBs) exhibit radio jets, whose properties depend on the X-ray spectral state and history of the source. There is general agreement about the type of the accretion disk around the compact object in the various spectral states. What is missing is a physical explanation for the appearance, disappearance, and re-appearance of jets. We will demonstrate that by invoking a simple physical mechanism proposed more than ten years ago, the so-called Poynting-Robertson Cosmic Battery (PRCB), we can explain in a natural way the disk–jet connection in XRBs.

scholarly journals Be X-ray binaries in the SMC as indicators of mass-transfer efficiency

2020 ◽  
Vol 498 (4) ◽  
pp. 4705-4720 ◽  
Author(s):  
Serena Vinciguerra ◽  
Coenraad J Neijssel ◽  
Alejandro Vigna-Gómez ◽  
Ilya Mandel ◽  
Philipp Podsiadlowski ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Star Formation ◽  
Compact Object ◽  
Star Formation History ◽  
Be Stars ◽  
X Ray ◽  
Formation History ◽  
History Of ◽  
Minimal Mass ◽  
X Ray Binaries

ABSTRACT Be X-ray binaries (BeXRBs) consist of rapidly rotating Be stars with neutron star (NS) companions accreting from the circumstellar emission disc. We compare the observed population of BeXRBs in the Small Magellanic Cloud (SMC) with simulated populations of BeXRB-like systems produced with the compas population synthesis code. We focus on the apparently higher minimal mass of Be stars in BeXRBs than in the Be population at large. Assuming that BeXRBs experienced only dynamically stable mass transfer, their mass distribution suggests that at least $\sim 30{{\ \rm per\ cent}}$ of the mass donated by the progenitor of the NS is typically accreted by the B-star companion. We expect these results to affect predictions for the population of double compact object mergers. A convolution of the simulated BeXRB population with the star formation history of the SMC shows that the excess of BeXRBs is most likely explained by this galaxy’s burst of star formation ∼20–40 Myr ago.

scholarly journals X-Ray Determination of the Black-Hole Mass in Cygnus X-1

1998 ◽  
Vol 188 ◽  
pp. 388-389
Author(s):  
A. Kubota ◽  
K. Makishima ◽  
T. Dotani ◽  
H. Inoue ◽  
K. Mitsuda ◽  
...  
Keyword(s):  
Black Hole ◽  
Compact Object ◽  
Optical Observations ◽  
Black Hole Mass ◽  
X Ray ◽  
Upper Limit ◽  
Supergiant Star ◽  
X Ray Binaries ◽  
Two Bodies

About 10 X-ray binaries in our Galaxy and LMC/SMC are considered to contain black hole candidates (BHCs). Among these objects, Cyg X-1 was identified as the first BHC, and it has led BHCs for more than 25 years(Oda 1977, Liang and Nolan 1984). It is a binary system composed of normal blue supergiant star and the X-ray emitting compact object. The orbital kinematics derived from optical observations indicates that the compact object is heavier than ~ 4.8 M⊙ (Herrero 1995), which well exceeds the upper limit mass for a neutron star(Kalogora 1996), where we assume the system consists of only two bodies. This has been the basis for BHC of Cyg X-1.

scholarly journals A Machine Learning Approach For Classifying Low-mass X-ray Binaries Based On Their Compact Object Nature

2020 ◽  
Author(s):  
R Pattnaik ◽  
K Sharma ◽  
K Alabarta ◽  
D Altamirano ◽  
M Chakraborty ◽  
...  
Keyword(s):  
Machine Learning ◽  
Black Hole ◽  
Neutron Star ◽  
Binary Systems ◽  
Compact Object ◽  
X Ray ◽  
Average Accuracy ◽  
Machine Learning Approach ◽  
Low Mass ◽  
X Ray Binaries

Abstract Low Mass X-ray binaries (LMXBs) are binary systems where one of the components is either a black hole or a neutron star and the other is a less massive star. It is challenging to unambiguously determine whether a LMXB hosts a black hole or a neutron star. In the last few decades, multiple observational works have tried, with different levels of success, to address this problem. In this paper, we explore the use of machine learning to tackle this observational challenge. We train a random forest classifier to identify the type of compact object using the energy spectrum in the energy range 5-25 keV obtained from the Rossi X-ray Timing Explorer archive. We report an average accuracy of 87±13% in classifying the spectra of LMXB sources. We further use the trained model for predicting the classes for LMXB systems with unknown or ambiguous classification. With the ever-increasing volume of astronomical data in the X-ray domain from present and upcoming missions (e.g., SWIFT, XMM-Newton, XARM, ATHENA, NICER), such methods can be extremely useful for faster and robust classification of X-ray sources and can also be deployed as part of the data reduction pipeline.

Evolution of low-mass X-ray binaries: dependence on the mass of the compact object

2012 ◽  
Vol 12 (10) ◽  
pp. 1417-1426 ◽  
Author(s):  
Qian Xu ◽  
Tao Li ◽  
Xiang-Dong Li
Keyword(s):  
Compact Object ◽  
X Ray ◽  
Low Mass ◽  
X Ray Binaries

scholarly journals Stellar Winds in Massive X-ray Binaries

2016 ◽  
Vol 12 (S329) ◽  
pp. 355-358
Author(s):  
Peter Kretschmar ◽  
Silvia Martínez-Núñez ◽  
Enrico Bozzo ◽  
Lidia M. Oskinova ◽  
Joachim Puls ◽  
...  
Keyword(s):  
Compact Object ◽  
High Mass ◽  
Stellar Winds ◽  
X Rays ◽  
X Ray ◽  
Current State ◽  
Wide Range ◽  
Strong Winds ◽  
The One ◽  
X Ray Binaries

AbstractStrong winds from massive stars are a topic of interest to a wide range of astrophysical fields. In High-Mass X-ray Binaries the presence of an accreting compact object on the one side allows to infer wind parameters from studies of the varying properties of the emitted X-rays; but on the other side the accretor’s gravity and ionizing radiation can strongly influence the wind flow. Based on a collaborative effort of astronomers both from the stellar wind and the X-ray community, this presentation attempts to review our current state of knowledge and indicate avenues for future progress.

scholarly journals Nonthermal processes in microquasars

2010 ◽  
Vol 6 (S275) ◽  
pp. 215-223
Author(s):  
Valentí Bosch-Ramon
Keyword(s):  
Thermal Emission ◽  
High Energy ◽  
Energy Bands ◽  
X Ray ◽  
Radio Jets ◽  
Extended Radio ◽  
Very High Energy ◽  
X Ray Binaries ◽  
Very High ◽  
Negligible Contribution

AbstractMicroquasars are X-ray binaries that show extended radio jets. These jets can accelerate particles up to relativistic energies that produce non-thermal emission from radio to TeV, and could also make a non-negligible contribution to the galactic CRs in some energy ranges. The orbital motion and compactness of these sources allow the study of high-energy astrophysical phenomena in extreme conditions that change in accessible timescales. In this work, I briefly discuss the production of broadband non-thermal emission in microquasars, putting special emphasis on the high- and the very high-energy bands.

scholarly journals A new possible accretion scenario for ultra-luminous X-ray sources

2019 ◽  
Vol 489 (1) ◽  
pp. 366-384 ◽  
Author(s):  
Shogo B Kobayashi ◽  
K Nakazawa ◽  
K Makishima
Keyword(s):  
Emission Lines ◽  
Emission Model ◽  
Massive Black Holes ◽  
X Ray ◽  
Local Structures ◽  
Upper Limits ◽  
Nearby Galaxies ◽  
Model Independent ◽  
Spectral States ◽  
Spectral State

ABSTRACT Using archival data from Suzaku, XMM–Newton, and NuSTAR, nine representative ultra-luminous X-ray sources (ULXs) in nearby galaxies were studied. Their X-ray spectra were all reproduced with a multicolour disc emission model plus its Comptonization. However, the spectral shapes of individual sources changed systematically depending on the luminosity, and defined three typical spectral states. These states differ either in the ratio between the Comptonizing electron temperature and the innermost disc temperature, or in the product of Compton y-parameter and fraction of the Comptonized disc photons. The luminosity range at which a particular state emerges was found to scatter by a factor of up to 16 among the eight ULXs. By further assuming that the spectral state is uniquely determined by the Eddington ratio, the sample ULXs are inferred to exhibit a similar scatter in their masses. This gives a model-independent support to the interpretation of ULXs in terms of relatively massive black holes. None of the spectra showed noticeable local structures. Especially, no Fe K-shell absorption/emission lines were detected, with upper limits of 30–40 eV in equivalent width from the brightest three among the sample: NGC 1313 X-1, Holmberg IX X-1, and IC 342 X-1. These properties disfavour ordinary mass accretion from a massive companion star, and suggest direct Bondi–Hoyle accretion from dense parts of the interstellar medium.

Modeling of hydrodynamic processes within high-mass X-ray binaries

2018 ◽  
Vol 14 (S346) ◽  
pp. 197-201
Author(s):  
Petr Kurfürst ◽  
Jiří Krtička
Keyword(s):  
Mass Loss Rate ◽  
Compact Object ◽  
Supernova Explosion ◽  
High Mass ◽  
Be Stars ◽  
X Ray ◽  
Hydrodynamic Processes ◽  
Hydrodynamic Structure ◽  
X Ray Binaries ◽  
Circumstellar Environment

AbstractHigh-mass X-ray binaries belong to the brightest objects in the X-ray sky. They usually consist of a massive O or B star or a blue supergiant while the compact X-ray emitting component is a neutron star (NS) or a black hole. Intensive matter accretion onto the compact object can take place through different mechanisms: wind accretion, Roche-lobe overflow, or circumstellar disk. In our multi-dimensional models we perform numerical simulations of the accretion of matter onto a compact companion in case of Be/X-ray binaries. Using Bondi-Hoyle-Littleton approximation, we estimate the NS accretion rate. We determine the Be/X-ray binary disk hydrodynamic structure and compare its deviation from isolated Be stars’ disk. From the rate and morphology of the accretion flow and the X-ray luminosity we improve the estimate of the disk mass-loss rate. We also study the behavior of a binary system undergoing a supernova explosion, assuming a blue supergiant progenitor with an aspherical circumstellar environment.

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