scholarly journals Astrometric Observations of X-ray Binaries Using Very Long Baseline Interferometry

2014 ◽  
Vol 31 ◽  
Author(s):  
James C. A. Miller-Jones
Keyword(s):  
Proper Motion ◽  
Binary Systems ◽  
Very Long Baseline Interferometry ◽  
Jet Physics ◽  
Physical Parameters ◽  
X Ray ◽  
Long Baseline ◽  
Binary Evolution ◽  
Motion Studies

AbstractI review the astrophysical insights arising from high-precision astrometric observations of X-ray binary systems, focussing primarily (but not exclusively) on recent results with very long baseline interferometry. Accurate, model-independent distances from geometric parallax measurements can help determine physical parameters of the host binary system and constrain black hole spins via broadband X-ray spectral modelling. Long-term proper motion studies, combined with binary evolution calculations, can provide observational constraints on the formation mechanism of black holes. Finally, the astrometric residuals from parallax and proper motion fits can provide information on orbital sizes and jet physics. I end by discussing prospects for future progress in this field.

scholarly journals The superslow pulsation X-ray pulsars in high mass X-ray binaries

2012 ◽  
Vol 8 (S291) ◽  
pp. 203-206 ◽  
Author(s):  
Wei Wang
Keyword(s):  
Neutron Star ◽  
Binary Systems ◽  
High Mass ◽  
X Ray ◽  
Origin And Evolution ◽  
Surface Magnetic Field ◽  
Spin Period ◽  
Binary Evolution ◽  
X Ray Binaries

AbstractThere exists a special class of X-ray pulsars that exhibit very slow pulsation of Pspin > 1000 s in the high mass X-ray binaries (HMXBs). We have studied the temporal and spectral properties of these superslow pulsation neutron star binaries in hard X-ray bands with INTEGRAL observations. Long-term monitoring observations find spin period evolution of two sources: spin-down trend for 4U 2206+54 (Pspin ~ 5560 s with Ṗspin ~ 4.9 × 10−7 s s−1) and long-term spin-up trend for 2S 0114+65 (Pspin ~ 9600 s with Ṗspin ~ −1 × 10−6 s s−1) in the last 20 years. A Be X-ray transient, SXP 1062 (Pspin ~ 1062 s), also showed a fast spin-down rate of Ṗspin ~ 3 × 10−6 s s−1 during an outburst. These superslow pulsation neutron stars cannot be produced in the standard X-ray binary evolution model unless the neutron star has a much stronger surface magnetic field (B > 1014 G). The physical origin of the superslow spin period is still unclear. The possible origin and evolution channels of the superslow pulsation X-ray pulsars are discussed. Superslow pulsation X-ray pulsars could be younger X-ray binary systems, still in the fast evolution phase preceding the final equilibrium state. Alternatively, they could be a new class of neutron star system – accreting magnetars.

scholarly journals A radio parallax to the black hole X-ray binary MAXI J1820+070

2020 ◽  
Vol 493 (1) ◽  
pp. L81-L86 ◽  
Author(s):  
P Atri ◽  
J C A Miller-Jones ◽  
A Bahramian ◽  
R M Plotkin ◽  
A T Deller ◽  
...  
Keyword(s):  
Black Hole ◽  
Inclination Angle ◽  
Precise Measurement ◽  
Very Long Baseline Interferometry ◽  
X Ray ◽  
Long Baseline ◽  
Model Independent ◽  
Jet Velocity ◽  
Very Long Baseline Array

ABSTRACT Using the Very Long Baseline Array and the European Very Long Baseline Interferometry Network, we have made a precise measurement of the radio parallax of the black hole X-ray binary MAXI J1820+070, providing a model-independent distance to the source. Our parallax measurement of (0.348 ± 0.033) mas for MAXI J1820+070 translates to a distance of (2.96 ± 0.33) kpc. This distance implies that the source reached (15 ± 3) per cent of the Eddington luminosity at the peak of its outburst. Further, we use this distance to refine previous estimates of the jet inclination angle, jet velocity, and the mass of the black hole in MAXI J1820+070 to be (63 ± 3)°, (0.89 ± 0.09) c, and (9.2 ± 1.3) M⊙, respectively.

scholarly journals The Be/X-ray binary LS 992/RX J0812.4-3114: Physical parameters and long-term variability

2001 ◽  
Vol 367 (1) ◽  
pp. 266-272 ◽  
Author(s):  
P. Reig ◽  
I. Negueruela ◽  
D. A. H. Buckley ◽  
M. J. Coe ◽  
J. Fabregat ◽  
...  
Keyword(s):  
Physical Parameters ◽  
X Ray

Very-Long-Baseline Interferometry Applied to Geophysics

1993 ◽  
Vol 156 ◽  
pp. 133-144
Author(s):  
W. E. Carter ◽  
D. S. Robertson
Keyword(s):  
Very Long Baseline Interferometry ◽  
Tide Gauge ◽  
Global Changes ◽  
Long Baseline ◽  
Tidal Forces ◽  
The Earth ◽  
Tide Gauge Measurements ◽  
Rotation Of The Earth ◽  
Global Reference Frame

Very-long-baseline Interferometry (VLBI) has opened for study a broad new spectrum of geophysical phenomena including: direct observation of the tectonic motions and deformations of the Earth's crustal plates, observations of unprecedented detail of the variations in the rotation of the Earth, and direct measurement of the elastic deformations of the Earth in response to tidal forces. These new measurements have placed significant constraints on models of the interior structure of the Earth; for example, measurements of the variations in the Earth's nutation have been shown to be particularly sensitive to the shape of the core-mantle boundary. The VLBI measurements will allow us to construct a global reference frame accurate at the centimeter level. Such a frame will be essential to studying long-term global changes, especially those changes related to sea-level variations as recorded by tide gauge measurements.

scholarly journals Glimpses of Be Binary Evolution

2000 ◽  
Vol 175 ◽  
pp. 668-680 ◽  
Author(s):  
Douglas R. Gies
Keyword(s):  
Neutron Stars ◽  
Binary Systems ◽  
Rotational Velocity ◽  
Close Binary ◽  
Be Stars ◽  
Star System ◽  
Single Star ◽  
X Ray ◽  
Binary Evolution ◽  
X Ray Binaries

AbstractModels of close binary evolution predict that mass gainers will be spun up to speeds close to the critical rotational velocity while the mass donors will appear as stripped down He stars, white dwarfs, or neutron stars. I argue here that the mass gainers are closely related to the Be stars. I present a list of the known Be binary systems which consists of those with bright, Roche-filling companions and those with faint or undetected companions. Notably absent are Be + B systems which are expected if the Be phase is a stage in the life of a single star. We now have the first example of a Be + He star system in the binary, ϕ Per, and taken together with the well known Be X-ray binaries, there is clear evidence that some fraction of Be stars are created in binaries; whether all such rapid rotators are so formed remains unknown.

scholarly journals Prospects for the Discovery of Black Hole Binaries without Mass Accretion with Gaia

2016 ◽  
Vol 12 (S324) ◽  
pp. 41-42
Author(s):  
Norita Kawanaka ◽  
Masaki Yamaguchi ◽  
Tsvi Piran ◽  
Tomasz Bulik
Keyword(s):  
Mass Transfer ◽  
Black Holes ◽  
Black Hole ◽  
Orbital Period ◽  
Proper Motion ◽  
Binary Systems ◽  
Evolution Model ◽  
Black Hole Binaries ◽  
Black Hole Binary ◽  
Binary Evolution

AbstractWe study the prospect for Gaia to detect black hole binary systems without the mass transfer from their companion stars. Gaia will be able to discover Galactic black holes without mass accretion by detecting the proper motion of their companion stars. We evaluate the number of such black hole binaries which have the orbital period short enough to be detected by Gaia during its operation, taking into account the binary evolution model.

LMC X–4: Different Types of Long-Term Variability

2017 ◽  
Vol 14 (S339) ◽  
pp. 146-146
Author(s):  
S. Molkov
Keyword(s):  
Binary Systems ◽  
Noise Model ◽  
High Mass ◽  
Time Interval ◽  
Spin Torque ◽  
X Ray ◽  
Spin Period ◽  
Different Types ◽  
First Time

AbstractThis talk presented a summary of our study of different types of long-term variability in the high-mass X-ray binary LMC X-4, by taking advantage of more than 43 years of measurements in the X-ray domain. In particular, we investigated the 30-day cycle of modulation of the X-ray emission from the source (super-orbital or precessional variability), and refined the orbital period and its first derivative. We showed that the precession period in the time-interval 1991–2015 is near its equilibrium value of Psup = 30.370 days, while the observed historical changes in the phase of this variability can be interpreted in terms of the ‘red noise’ model. We obtained an analytical law from which the precession phase can be determined to within 5% throughout the entire time-interval under consideration. Our analysis revealed for the first time that the source is displaying near-periodic variations of its spin period, on a time-scale of roughly 6.8 years, thus making LMC X-4 one of the (few) known binary systems that show remarkable long-term spin–torque reversals.

scholarly journals Observations of Low Mass X-Ray Binaries

1996 ◽  
Vol 158 ◽  
pp. 349-358
Author(s):  
Alan P. Smale
Keyword(s):  
Neutron Stars ◽  
Orbital Period ◽  
Binary Systems ◽  
Light Curves ◽  
X Ray ◽  
Fast Timing ◽  
Low Mass ◽  
And Behavior ◽  
X Ray Binaries

AbstractIn this paper I review the properties and behavior of low-mass X-ray binary systems (LMXBs) that contain neutron stars (NS), concentrating on the Galactic bulge sources and bursters. I describe the observed characteristics of LMXBs including their light curves, spectra, eclipses, dips, bursts, flares, pulsations, QPO, long-term periodicities and orbital period changes, and explain how fast timing results and the distinction between ‘Z’ and ‘atoll’-type sources provide the key to a unified model of LMXB behavior.

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