scholarly journals Low-frequency quasi-periodic oscillations in low-mass X-ray binaries and galactic black hole candidates

1994 ◽  
Vol 431 ◽  
pp. 732 ◽  
Author(s):  
Xingming Chen ◽  
Ronald E. Taam
2019 ◽  
Vol 490 (4) ◽  
pp. 5270-5284 ◽  
Author(s):  
Marieke van Doesburgh ◽  
Michiel van der Klis

ABSTRACT We investigate frequency correlations of low frequency (LF, <80 Hz) and kHz quasi-periodic oscillations (QPOs) using the complete RXTE data sets on six accreting millisecond X-ray pulsars (AMXPs) and compare them to those of non-pulsating neutron star (NS) low-mass X-ray binaries with known spin. For the AMXPs SAX J1808.4−3658 and XTE J1807−294, we find frequency-correlation power-law indices that, surprisingly, are significantly lower than in the non-pulsars, and consistent with the relativistic precession model (RPM) prediction of 2.0 appropriate to test-particle orbital and Lense–Thirring precession frequencies. As previously reported, power-law normalizations are significantly higher in these AMXPs than in the non-pulsating sources, leading to requirements on the NS specific moment of inertia in this model that cannot be satisfied with realistic equations of state. At least two other AMXPs show frequency correlations inconsistent with those of SAX J1808.4−3658 and XTE J1807−294, and possibly similar to those of the non-pulsating sources; for two AMXPs no conclusions could be drawn. We discuss these results in the context of a model that has had success in black hole (BH) systems involving a torus-like hot inner flow precessing due to (prograde) frame dragging, and a scenario in which additional (retrograde) magnetic and classical precession torques not present in BH systems are also considered. We show that a combination of these interpretations may accommodate our results.


2016 ◽  
Vol 457 (1) ◽  
pp. 1015-1027 ◽  
Author(s):  
Chen Wang ◽  
Kun Jia ◽  
Xiang-Dong Li

1996 ◽  
Vol 165 ◽  
pp. 93-103
Author(s):  
Roger W. Romani

The presence of accreting black holes (BH) among the X-ray binaries has been recognized for many years. Traditionally, Cyg X-1 and the handful of other candidates have been thought of as cousins of the HMXB neutron star systems. Recent studies of the soft X-ray transients such as A 0620-00 have, however, shown that the dynamical evidence makes these low-mass systems very strong black-hole candidates. Further, analysis of the eventual end-states of various high-mass X-ray binaries suggest that some could end as observable BH-pulsar binaries, although the first such system is yet to be discovered.


1987 ◽  
Vol 125 ◽  
pp. 321-331
Author(s):  
M. van der Klis

The properties of the rapid, persistent quasi-periodic oscillations (QPO) discovered with EXOSAT in the X-ray flux of at least 7 bright low-mass X-ray binaries are described. Particular attention is given to the various relations observed between QPO frequency and X-ray intensity, the link between QPO and the low-frequency noise in the X-ray intensity and the bimodal properties of in particular Sco X-1, GX 5-1 and Cyg X-2. The merits of the hypothesis that the QPO indicate the presence of a neutron star with a magnetosphere are considered.


2012 ◽  
Vol 12 (6) ◽  
pp. 661-670 ◽  
Author(s):  
Zhi-Yun Wang ◽  
Chang-Yin Huang ◽  
Ding-Xiong Wang ◽  
Jiu-Zhou Wang

1996 ◽  
Vol 165 ◽  
pp. 301-312
Author(s):  
M. Van Der Klis

Recent developments in the field of low-mass X-ray binaries are briefly reviewed, with particular emphasis on a comparison between the systems that contain accreting low magnetic-field neutron stars and those that contain black-hole candidates. The possibility that inclination effects play a role in black-hole candidate phenomenology is explored.


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