Long-term cycles in cosmic X-ray sources

  title={Long-term cycles in cosmic X-ray sources},
  author={William C. Priedhorsky and Stephen S. Holt},
  journal={Space Science Reviews},
Most of what we know about galactic X-ray binaries comes from their time variation, particularly periodic variations corresponding to neutron star rotation, and binary motion. Longer cycles or quasi-cycles are much harder to observe because of the shortage of instrumentation suitable for long-term monitoring. Nonetheless, cycle with periods up to a few years have been seen in several galactic binaries.Cycles of ∼ 30–300 days have been confirmed for four high-mass systems, LMC X-4, Her X-1… 

Long-term X-ray variability and state transition of GX 339-4

With extensive monitoring data spanning over 30 years from Vela 5B, Ariel 5, Ginga, Compton Gamma Ray Observatory, Rossi X-ray Timing Explorer and BeppoSAX, we find evidence for long-term X-ray

4U 2206+54: An Unusual High-Mass X-Ray Binary with a 9.6 Day Orbital Period But No Strong Pulsations

Rossi X-Ray Timing Explorer (RXTE) All-Sky Monitor observations of the X-ray source 4U 2206+54, previously proposed to be a Be star system, show the X-ray flux to be modulated with a period of

Decade time-scale modulation of low-mass X-ray binaries

Regular observations by the All-Sky Monitor aboard the Rossi X-ray Timing Explorer satellite have yielded well-sampled light curves with a time baseline of over 10 years. We find that up to eight of

GS2023+338: a new class of X-ray transient source?

TRANSIENT X-ray sources are generally considered to comprise accreting binary systems containing either a black hole or a neutron star1–5. The transient X-ray emission is thought to result from

Reproductions of super-orbital X-ray light-curves with the precessing accretion ring model and implications on accretion flows through accretion rings

  • H. Inoue
  • Physics
    Publications of the Astronomical Society of Japan
  • 2019
X-ray light curves of three X-ray pulsars, SMC X-1, LMC X-4 and Her X-1, folded with their respective super-orbital periods, are shown to be well reproduced by a model in which X-rays from a compact


Contemporary Physics, 1991, Vol. 32, no. 2, 103- 119 Neutron stars and black holes in binary systems VIRGINIA TRIMBLE Neutron stars and black holes can find themselves with close stellar companions


Rossi X-ray Timing Explorer observations of the black hole binary LMC X-3 reveal an extended very low X-ray state lasting from 2003 December 13 until 2004 March 18, unprecedented both in terms of its


We present an improved method for determining the mass of neutron stars in eclipsing X-ray pulsar binaries and apply the method to six systems, namely, Vela X-1, 4U 1538-52, SMC X-1, LMC X-4, Cen

X-ray observations of accretion disks

  • H. Inoue
  • Physics
    Publications of the Astronomical Society of Japan
  • 2021
Present understandings of accretion disks based on X-ray observations are reviewed. The main focus is on observational properties of accretion disks around black holes in X-ray binaries and their



The structure of low-mass X-ray binaries

The present knowledge of the structure of low-mass X-ray binary systems is reviewed. We examine the orbital period distribution of these sources and discuss how the orbital periods are measured.

Discovery of 69 ms periodic X-ray pulsations in A0538 — 66

Both the recurrent X-ray transient A0538–66 and its optical counterpart undergo outbursts at intervals which are multiples of 16.6 days1–3. The times of outbursts are subject to appreciable jitter

On fast X-ray rotators with long-term periodicities

Using previous results from SAS 3 observations supported by the results of new observations with the Monitor Proportional Counter on board the Einstein Observatory (HEAO 2), we show that the

Her X-1: A Processing Binary Pulsar?

This work states that even for a modest mass transfer rate, 2023 g yr−1, the maximum probable X-ray luminosity Lx≈1036 erg s−1 can be accommodated (assuming GM/Rc2∼10−1 as in a neutron star).

Discovery of 13.5 s X-Ray Pulsations from LMC X-4

X-ray pulsations with a 13.5-sec period have been detected from the 1.4-d X-ray binary LMC X-4. By measuring the apparent pulse period at several binary orbital phases, and assuming the orbit to be

Nodding motions of accretion rings and disks - A short-term period in SS 433

It is pointed out that accretion disks and rings in mass transfer binaries have been observed spectroscopically and calculated theoretically for many years. The present investigation is partly based

The long-term intensity behavior of Centaurus X-3

In three years of observation, the X-ray source Cen X-3 appears to alternate between 'high states', with an intensity of 150 counts/s (2-6 keV) or greater, and 'low states', where the source is

Orbital period changes in Centaurus X-3

Two new times of mid-X-ray eclipse for Cen X-3 are presented on the basis of pulse arrival time analyses of pointed observations with SAS 3. When combined with all other published eclipse times based

The 41.5 day binary X-ray pulsar 4U 1223-62 (GX 301-2).

Ariel 5 and SAS 3 X-ray pulse timing data for the 700 s X-ray pulsar 4U 1223 - 62 (GX 301 - 2) are reexamined in order to deduce the orbital elements of this system. The Ariel 5/SAS 3 arrival times

Studies of optical pulsations from HZ Herculis/Hercules X-1: a determination of the mass of the neutron star.

In 500 hours of optical observations of this binary system we have repeatedly detected optical pulsations at the 0.1--0.3 percent level. These pulsations are present only for particular well-defined