We present a catalogue of low-mass X-ray binaries. The catalogue is an updated version of the catalogue of van Paradijs (1995). This new catalogue contains 150 sources, 31 new low-mass X-ray binaries in addition to the 119 sources listed in van Paradijs' catalogue. The aim of this catalogue is to help the reader gain easy access to the recent literature (up to about August 2000) on individual sources, and to provide of some basic information on the X-ray sources and their counterparts in other wavelength ranges (UV, optical, IR, and radio). In cases where there is some doubt about the low-mass nature of the X-ray binary, this is mentioned. In an appendix we list the Anomalous X-ray Pulsars (AXPs), which nowadays are no longer thought to be low-mass X-ray binaries.

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A catalogue of low-mass X-ray binaries

We have compiled contemporaneous broadband observations of the black hole candidate X-ray binary GX 339-4 when in the low/hard X-ray state in 1981 and 1997. The data clearly reveal the presence of two spectral components, with thermal and nonthermal spectra, overlapping in the optical-near-infrared bands. The nonthermal component lies on an extrapolation of the radio spectrum of the source, and we interpret it as optically thin synchrotron emission from the powerful, compact jet in the system. Detection of this break from self-absorbed to optically thin synchrotron emission from the jet allows us to place a firm lower limit on the ratio of jet (synchrotron) to X-ray luminosities of ≥5%. We further note that extrapolation of the optically thin synchrotron component from the near-infrared to higher frequencies coincides with the observed X-ray spectrum, supporting models in which the X-rays could originate via optically thin synchrotron emission from the jet (possibly instead of Comptonization).

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Near-infrared synchrotron emission from the compact jet of gx 339 4

We have studied the fast timing and spectral behavior of the black hole candidate (BHC) GX 339-4 using all 1-20 keV EXOSAT ME data: the 1983 July, 1984 March, 1984 May, and 1985 April observations. In 1985 April, GX 339-4 was in a weak low state (0.03 × 10-9 ergs cm-2 s-1, 2-10 keV). The X-ray spectrum was a hard power law with a photon index α of 1.82, and the power spectrum, though ill-constrained by the data, was consistent with a typical BHC low-state spectrum. During the other three pointings the system was brighter (1.5 × 10-9 ergs cm-2 s-1, 2-10 keV), an ultrasoft component was present in the spectrum, and the power law was steeper (α ~ 3.5 in 1984; in 1983 it was not well measured); the power spectrum showed a flat-topped band-limited noise component with a break frequency of ~4.5 Hz and a fractional rms amplitude of ~7%. Comparing flux levels, X-ray spectra, and power spectra, we conclude that in these observations GX 339-4 was in a state intermediate between the usual BHC low and high states. The system was ~4 times brighter than in its usual low state, 4 times fainter than in its usual high state, and an order of magnitude fainter than in its very high state. We compare these results to those recently obtained on other BHCs, and conclude that this "intermediate-state" behavior is a common characteristic of BHCs, which occurs at levels intermediate between the high and the low state. We argue that this result can be used to resolve the long-standing issue of the dependence of the power spectral break frequency in the low state on mass accretion rate, and strengthens the idea that low-state noise and very high state noise may have a common origin. We briefly discuss a possible interpretation for the changes in break frequency in the low state and between low state and intermediate state.

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The EXOSAT data on GX 339-4: further evidence for an "intermediate" state

The transient black-hole binary XTE J1118+480 exhibited dramatic rapid variability at all wavelengths which were suitably observed during its 2000 April–July outburst. We examine time-resolved X-ray, ultraviolet, optical and infrared data spanning the plateau phase of the outburst. We find that both X-ray and infrared bands show large amplitude variability. The ultraviolet and optical variability is more subdued, but clearly correlated with that seen in the X-rays. The ultraviolet, at least, appears to be dominated by the continuum, although the lines are also variable. Using the X-ray variations as a reference point, we find that the ultraviolet (UV) variability at long wavelengths occurs later than that at short wavelengths. Uncertainty in the Hubble Space Telescope timing prohibits a determination of the absolute lag with respect to the X-rays, however. The transfer function is clearly not a delta-function, exhibiting significant repeatable structure. For the main signal we can rule out an origin in reprocessing on the companion star – the lack of variation in the lags is not consistent with this, given a relatively high orbital inclination. Weak reprocessing from the disc and/or companion star may be present, but is not required, and another component must dominate the variability. This could be variable synchrotron emission correlated with X-ray variability, consistent with our earlier interpretation of the infrared (IR) flux as due to synchrotron emission rather than thermal disc emission. In fact, the broad-band energy distribution of the variability from IR to X-rays is consistent with expectations of optically thin synchrotron emission. We also follow the evolution of the low-frequency quasi-periodic oscillation in X-rays, UV, and optical. Its properties at all wavelengths are similar, indicating a common origin.

http://www.physics.purdue.edu/astro/CuiPapers/The%20remarkable%20rapid%20X-ray,%20ultraviolet,%20optical%20and%20infrared%20variability%20in%20the%20black%20hole%20XTE%20J1118+480.pdf

The remarkable rapid X-ray, ultraviolet, optical and infrared variability in the black hole XTE J1118+480

A rapid timing analysis of Very Large Telescope (VLT)/ULTRACAM (optical) and RXTE (X- ray) observations of the Galactic black hole binary GX 339−4 in the low/hard, post-outburst state of 2007 June is presented. The optical light curves in the r � ,gand ufilters show slow (∼20 s) quasi-periodic variability. Upon this is superposed fast flaring activity on times approaching the best time resolution probed (∼50 ms inrandg � ) and with maximum strengths of more than twice the local mean. Power spectral analysis over ∼0.004-10 Hz is presented, and shows that although the average optical variability amplitude is lower than that in X-rays, the peak variability power emerges at a higher Fourier frequency in the optical. Energetically, we measure a large optical versus X-ray flux ratio, higher than that seen on previous occasions when the source was fully jet dominated. Such a large ratio cannot be easily explained with a disc alone. Studying the optical-X-ray cross-spectrum in Fourier space shows a markedly different behaviour above and below ∼0.2 Hz. The peak of the coherence function above this threshold is associated with a short optical time lag with respect to X-rays, also seen as the dominant feature in the time-domain cross-correlation at ≈150 ms. The rms energy spectrum of these fast variations is best described by distinct physical components over the optical and X-ray regimes, and also suggests a maximal irradiated disc fraction of 20 per cent around 5000 A. If the constant time delay is due to propagation of fluctuations to (or within) the jet, this is the clearest optical evidence to date of the location of this component. The low-frequency quasi-periodic oscillation is seen in the optical but not in X-rays, and is associated with a low coherence. Evidence of reprocessing emerges at the lowest Fourier frequencies, with optical lags at ∼10 s and strong coherence in the blue ufilter. Consistent with this, simultaneous optical spectroscopy also shows the Bowen fluorescence blend, though its emission location is

/pdf/rapid-optical-and-x-ray-timing-observations-of-gx-339-4-2p738luzvq.pdf

Rapid optical and X-ray timing observations of GX 339−4: multicomponent optical variability in the low/hard state

We review results of correlated IR, optical and X-ray observations of GX 339-4 made from March 1981 through May 1984. In the soft X-ray state, the object does not show outstanding optical and X-ray variability. Night-to-night smooth optical variations of 0.3 magnitudes were however present during one observing run. In contrast, the hard X-ray state is characterised by strong erratic optical and X-ray fluctuations on time scales from 20 milliseconds to seconds, as well as 7 to 20 second quasi-periodic oscillations. The optical counterpart appears much redder in the IR during the hard state. Particular attention is drawn to the hard to soft X-ray transition which occured in June 1981. The shape of the IR to X-ray energy distribution is discussed. The unusual features of this ‘black hole candidate’ are examined in the framework of the current theories of accretion.

https://link.springer.com/content/pdf/10.1007/BF00212888.pdf

An IR, Optical and X-Ray Study of the Two State Behaviour of GX 339-4

We present preliminary results from V-band CCD photometric observations of several low-mass X-ray binaries with faint optical counterparts obtained at ESO and CFHT from February to September 1984. LMCX-2 exhibits large (0.3–0.5 magnitude) variations consistent with a possible 6.4 hour period. 1556–605 shows 0.2–0.5 magnitude variations suggesting that the orbital period is longer than 7 hours. 1957+115 shows short time scale (1 hour) variations of 0.1 magnitude.

CCD Photometry of Low Mass X-Ray Binaries: LMCX-2, 1556–60 and 1957+11

The strongest X-ray point source, LHG 83, discovered in the EINSTEIN survey of the LMC and not being associated with a nearby coronal type stellar emitter or background AGN is identified with a faint blue variable object. Spectrophotometry reveals low mass X-ray binary characteristics at a mean velocity consistent with LMC membership. The He II A4686 emission exhibits a unique blue shifted component suggesting outflow velocities of several thousand km/s. Optical brightness changes by 0.3 mag in less than one hour are likely to be intrinsic to the source rather than induced by orbital motion. The low X-ray to optical flux ratio is probably due to the fact that the central X-ray source is blocked from direct view by the accretion disk.

C. Chevalier

Papers

An IR, Optical and X-Ray Study of the Two State Behaviour of GX 339-4

CCD Photometry of Low Mass X-Ray Binaries: LMCX-2, 1556–60 and 1957+11

LHG 83: Another Outstanding X-Ray Binary in the LMC

LHG83 - another Outstanding X-Ray Binary in the Large Magellanic Cloud

The Optical Light Curve of Large Magellanic CLOUD-X-4 and the 30-DAY X-Ray Period