scholarly journals Observations of Binaries and Evolutionary Implications

1984 ◽  
Vol 80 ◽  
pp. 199-227
Author(s):  
C. De Loore
Keyword(s):  
Mass Transfer ◽  
Angular Momentum ◽  
Mass Transfer Process ◽  
Transfer Phase ◽  
X Ray ◽  
Special Cases ◽  
Angular Momentum Loss ◽  
Spectral Ranges ◽  
X Ray Binaries

AbstractComparison of the characteristics of groups of stars in various evolutionary phases and the study of individual systems allow to make estimates of the parameters governing mass loss and mass transfer. Observations enable us in a few cases to determine geometric models for binaries during or after the mass transfer phase (disks, rings, common envelopes, symbiotics, interacting binaries, compact components).From spectra taken at different phases, radial velocity curves can be derived and masses and radii can be determined. In special cases spectra in different spectral ranges (visual, UV, X-ray) are required for the determination of the radial velocities of the two components (for X-ray binaries, for systems with hot and cool components). Information on parameters related to the mass transfer process enables us to consider non conservative evolution - i.e. the computation of evolutionary sequences with the assumption that mass and angular momentum not only are transferred from one of the components towards the other one, but that also mass and angular momentum can leave the system. Careful and detailed analysis of the observations allows in certain cases to determine the parameters governing this mass and angular momentum loss, and for contact phases, to determine the degree of contact.

scholarly journals Evolution of black-hole intermediate-mass X-ray binaries

2006 ◽  
Vol 2 (S238) ◽  
pp. 339-340
Author(s):  
Wen-Cong Chen ◽  
Xiang-Dong Li
Keyword(s):  
Black Hole ◽  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Intermediate Mass ◽  
X Ray ◽  
Angular Momentum Loss ◽  
Low Mass ◽  
Plausible Mechanism ◽  
X Ray Binaries ◽  
Mass Form

AbstractWe propose a plausible mechanism for orbital angular momentum loss in black-hole intermediate-mass X-ray binaries, assuming that a small fraction of the transferred mass form a circumbinary disc. The disc can effectively drain orbital angular momentum from the binary, leading to the formation of compact black-hole low-mass X-ray binaries. This scenario also suggests the possible existence of luminous, persistent black hole low-mass X-ray binaries.

scholarly journals The evolutionary history of BE/X-ray binaries

1984 ◽  
Vol 105 ◽  
pp. 399-402 ◽  
Author(s):  
G.M.H.J. Habets
Keyword(s):  
Mass Transfer ◽  
Evolutionary History ◽  
Transfer Phase ◽  
Intermediate Mass ◽  
X Ray ◽  
History Of ◽  
Helium Star ◽  
X Ray Binaries

A 2.5 M⊙helium star remnant of a Case B mass transfer is evolved to off-centre neon ignition and a second mass transfer phase, Case BB, is explored. The model for the formation of Be/X-ray binaries by mass-transfer dominated evolution in an intermediate mass binary is confirmed.

scholarly journals Surrounded by spiders! New black widows and redbacks in the Galactic field

2012 ◽  
Vol 8 (S291) ◽  
pp. 127-132 ◽  
Author(s):  
Mallory S. E. Roberts
Keyword(s):  
Mass Transfer ◽  
Transfer Process ◽  
Gamma Ray ◽  
Mass Transfer Process ◽  
Millisecond Pulsar ◽  
X Ray ◽  
Galactic Field ◽  
Multi Wavelength ◽  
Low Mass ◽  
X Ray Binaries

AbstractOver the last few years, the number of known eclipsing radio millisecond pulsar systems in the Galactic field has dramatically increased, with many being associated with Fermi gamma-ray sources. All are in tight binaries (orbital period < 24 hr) with many being classical “black widows” which have very low mass companions (companion mass Mc ≪ 0.1 M⊙) but some are “redbacks” with low mass (Mc ~ 0.2-0.4 M⊙) companions which are probably non-degenerate. These latter are systems where the mass transfer process may have only temporarily halted, and so are transitional systems between low mass X-ray binaries and ordinary binary millisecond pulsars. Here we review the new discoveries and their multi-wavelength properties, and briefly discuss models of shock emission, mass determinations, and evolutionary scenarios.

scholarly journals Late-time evolution of ultracompact X-ray binaries

2012 ◽  
Vol 8 (S290) ◽  
pp. 153-156
Author(s):  
L. M. van Haaften ◽  
G. Nelemans ◽  
R. Voss
Keyword(s):  
Mass Transfer ◽  
Time Evolution ◽  
Dynamical Instability ◽  
Wave Radiation ◽  
Late Time ◽  
X Ray ◽  
Long Period ◽  
Angular Momentum Loss ◽  
Orbital Periods ◽  
X Ray Binaries

AbstractUltracompact X-ray binaries (UCXBs) have orbital periods shorter than about 80 minutes and typically consist of a neutron star that accretes hydrogen-poor matter from a white dwarf companion. Angular momentum loss via gravitational wave radiation drives mass transfer via Roche-lobe overflow. The late-time evolution of UCXBs is poorly understood – all 13 known systems are relatively young and it is not clear why. One question is whether old UCXBs actually still exist, or have they become disrupted at some point? Alternatively they may be simply too faint to see. To investigate this, we apply the theories of dynamical instability, the magnetic propeller effect, and evaporation of the donor, to the UCXB evolution. We find that both the propeller effect and evaporation are promising explanations for the absence of observed long-period UCXBs.

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.

Constraining Progenitors of Observed Low-mass X-ray Binaries Using Convection and Rotation-Boosted Magnetic Braking

2021 ◽  
Vol 922 (2) ◽  
pp. 174
Author(s):  
Kenny X. Van ◽  
Natalia Ivanova
Keyword(s):  
Mass Transfer ◽  
Binary Systems ◽  
Formation Rate ◽  
Mass Transfer Rate ◽  
Population Synthesis ◽  
X Ray ◽  
Synthesis Technique ◽  
Low Mass ◽  
Magnetic Braking ◽  
X Ray Binaries

Abstract We present a new method for constraining the mass transfer evolution of low-mass X-ray binaries (LMXBs)—a reverse population synthesis technique. This is done using the detailed 1D stellar evolution code MESA (Modules for Experiments in Stellar Astrophysics) to evolve a high-resolution grid of binary systems spanning a comprehensive range of initial donor masses and orbital periods. We use the recently developed convection and rotation-boosted (CARB) magnetic braking scheme. The CARB magnetic braking scheme is the only magnetic braking prescription capable of reproducing an entire sample of well-studied persistent LMXBs—those with mass ratios, periods, and mass transfer rates that have been observationally determined. Using the reverse population synthesis technique, where we follow any simulated system that successfully reproduces an observed LMXB backward, we have constrained possible progenitors for each observed well-studied persistent LMXB. We also determined that the minimum number of LMXB formations in the Milky Way is 1500 per Gyr if we exclude Cyg X-2. For Cyg X-2, the most likely formation rate is 9000 LMXB Gyr−1. The technique we describe can be applied to any observed LMXB with well-constrained mass ratio, period, and mass transfer rate. With the upcoming GAIA DR3 containing information on binary systems, this technique can be applied to the data release to search for progenitors of observed persistent LMXBs.

scholarly journals Modeling of Oxygen-Neon Dominated Accretion Disks in Ultracompact X-Ray Binaries: 4U 1626-67

2004 ◽  
Vol 194 ◽  
pp. 146-147 ◽  
Author(s):  
K. Werner ◽  
T. Nagel ◽  
S. Dreizler ◽  
T. Rauch
Keyword(s):  
Accretion Disks ◽  
Important Process ◽  
Gravitational Settling ◽  
X Ray ◽  
The Core ◽  
Synthetic Spectra ◽  
First Results ◽  
Low Mass ◽  
X Ray Binaries

AbstractWe report on first results of computing synthetic spectra from H/He-poor accretion disks in ultracompact LMXBs. We aim at the determination of the chemical composition of the very low-mass donor star, which is the core of a former C/O white dwarf. The abundance analysis allows to draw conclusions on gravitational settling in WDs which is an important process affecting cooling times and pulsational g-mode periods.

scholarly journals Mass transfer on a nuclear timescale in models of supergiant and ultra-luminous X-ray binaries

2019 ◽  
Vol 628 ◽  
pp. A19 ◽  
Author(s):  
M. Quast ◽  
N. Langer ◽  
T. M. Tauris
Keyword(s):  
Mass Transfer ◽  
Black Hole ◽  
Neutron Star ◽  
Roche Lobe ◽  
High Mass ◽  
X Rays ◽  
X Ray ◽  
Mass Ratios ◽  
X Ray Binaries ◽  
Eddington Limit

Context. The origin and number of the Galactic supergiant X-ray binaries is currently not well understood. They consist of an evolved massive star and a neutron star or black-hole companion. X-rays are thought to be generated from the accretion of wind material donated by the supergiant, while mass transfer due to Roche-lobe overflow is mostly disregarded because the high mass ratios of these systems are thought to render this process unstable. Aims. We investigate how the proximity of supergiant donor stars to the Eddington limit, and their advanced evolutionary stage, may influence the evolution of massive and ultra-luminous X-ray binaries with supergiant donor stars (SGXBs and ULXs). Methods. We constructed models of massive stars with different internal hydrogen and helium gradients (H/He gradients) and different hydrogen-rich envelope masses, and exposed them to slow mass-loss to probe the response of the stellar radius. In addition, we computed the corresponding Roche-lobe overflow mass-transfer evolution with our detailed binary stellar evolution code, approximating the compact objects as point masses. Results. We find that a H/He gradient in the layers beneath the surface, as it is likely present in the well-studied donor stars of observed SGBXs, can enable mass transfer in SGXBs on a nuclear timescale with a black-hole or a neutron star accretor, even for mass ratios in excess of 20. In our binary evolution models, the donor stars rapidly decrease their thermal equilibrium radius and can therefore cope with the inevitably strong orbital contraction imposed by the high mass ratio. We find that the orbital period derivatives of our models agree well with empirical values. We argue that the SGXB phase may be preceded by a common-envelope evolution. The envelope inflation near the Eddington limit means that this mechanism more likely occurs at high metallicity. Conclusion. Our results open a new perspective for understanding that SGBXs are numerous in our Galaxy and are almost completely absent in the Small Magellanic Cloud. Our results may also offer a way to find more ULX systems, to detect mass transfer on nuclear timescales in ULX systems even with neutron star accretors, and shed new light on the origin of the strong B-field in these neutron stars.

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