Observational properties of accretion discs: Precessing and warped?

Charles, P. A.; Clarkson, W. I.; Cornelisse, R.; Shih, C. Y.

doi:10.1016/j.newar.2008.03.025

Cited by 25 publications

(35 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The quantity and quality of the ASM archive has stimulated significant interest in the long‐term variability properties of X‐ray binaries. This can be seen in the overview articles by Wen et al (2006), Sood et al (2007) and Charles et al (2008), with the last describing at least six different mechanisms by which superorbital periodicities (observable in X‐ray and/or optical light curves) can manifest themselves. Unfortunately, we do not yet know the orbital period or even the nature of the donor star in IGR J17098−3628, but the similarity of its long‐term X‐ray behaviour to EXO 0748−676 suggests that we can infer what these properties might be.…”

Section: Discussionmentioning

confidence: 99%

“…When precession and warping are coupled, the resultant precessing warped accretion disc would manifest itself as the observed superorbital periods. These are types 2, 3 and 5 in the categorization of Charles et al (2008).…”

Section: Discussionmentioning

confidence: 99%

“…Long‐term, non‐orbital periodicities, ranging from 10 to 100 d, were first discovered in the early days of X‐ray astronomy (see Charles et al 2008 for a recent review). Some of these are remarkably stable (e.g.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Discovery of long-term superorbital periodicities in the pseudo-transient LMXBs: IGR J17098−3628 and EXO 0748−676

Kotze¹,

Charles²,

Crause³

2009

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

Long‐term monitoring of the recently discovered X‐ray transient, IGR J17098−3628, by the All‐Sky Monitor on‐board the Rossi X‐Ray Timing Explorer, has shown that it displays a long‐term (≈163 d) quasi‐periodic modulation in the data spanning its ‘active’ state (i.e. approximately MJD 53450–54200). Furthermore, this light curve is not typical of ‘classical’ soft X‐ray transients, in that J17098−3628 has remained active since its initial discovery, and may be more akin to the pseudo‐transient EXO 0748−676, which is now classified as a persistent low‐mass X‐ray binary (LMXB). However, EXO 0748−676 recently entered a more active phase (since approximately MJD 53050), and since then we find that it too displays a quasi‐periodic modulation (≈181 d) in its light curve. This must be a ‘superorbital’ modulation, as the orbital period of EXO 0748−676 is well established (3.8 h), and hence we interpret both objects' long periods as representing some intrinsic properties of the accretion disc (such as coupled precessional and warping effects). By analogy, we therefore suggest that IGR J17098−3628 is another member of this class of pseudo‐transient LMXBs and is likely to have a <1 d orbital period.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Discovery of long-term superorbital periodicities in the pseudo-transient LMXBs: IGR J17098−3628 and EXO 0748−676

Kotze¹,

Charles²,

Crause³

2009

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

show abstract

“…Long‐term, non‐orbital, quasi‐periodic variations on time‐scales of approximately tens to hundreds of days in LMXBs were discovered early in X‐ray astronomy (see Charles et al 2008 for a recent review). These ‘super‐orbital’ periods are thought to be related to the properties of the accretion disc, and there are two basic mechanisms actively under consideration: radiation‐induced warping (Ogilvie & Dubus 2001) and precession (Whitehurst & King 1991) of the accretion disc.…”

Section: Introductionmentioning

confidence: 99%

Very long-term X-ray variations in LMXBs: solar cycle-like variations in the donor?

Kotze

Charles

2010

Monthly Notices of the Royal Astronomical Society: Letters

View full text Add to dashboard Cite

Long‐term monitoring of Low Mass X‐ray Binaries (LMXBs) by the All Sky Monitor on board the Rossi X‐ray Timing Explorer now covers ∼13 yr and shows that certain LMXB types display very long‐term (approximately several to tens of years) quasi‐periodic modulations. These time‐scales are much longer than any ‘super‐orbital’ periods reported hitherto and likely have a different origin. We suggest here that they are due to long‐term variations in the mass‐transfer rate from the donor, which are a consequence of solar‐like magnetic cycles that lead to Porb changes (as proposed by Richman, Applegate & Patterson for similar long‐term variations in cataclysmic variables). Atoll sources display much larger amplitude modulations than Z sources over these time‐scales, presumably because Z sources are Eddington limited and hence unable to respond as readily as Atoll sources to fluctuations in the mass‐transfer rate from the donor.

show abstract

“…These so-called superorbital modulations, or P sup , have different properties in different types of interacting binaries, that led [7] to identify 6 such types. Here we add a seventh, and make a number of clarifying remarks on this categorisation.…”

Section: Introductionmentioning

confidence: 99%

Long-Term Optical∕X-ray Variability of CVs, LMXBs and BeX Sources

Charles¹,

Kotze²,

Rajoelimanana³

2010

AIP Conference Proceedings

Self Cite

View full text Add to dashboard Cite

The superorbital variability and triple nature of the X-ray source 4U 1820-303 AIP Conf.Abstract. The study of long-term variability of interacting binaries has been revolutionised at X-ray and optical wavelengths by RXTE's all-sky monitor, combined with ground-based wide-field optical monitoring of the Magellanic Clouds and galactic bulge regions. We present a summary of long-term, super-orbital X-ray modulations detected in luminous galactic X-ray binaries, with particular emphasis on the recently identified multi-year modulations which may be related to solar-cycle-like variations in the low-mass donor stars. The MACHO and OGLE databases of SMC optical monitoring have revealed long-term (200-3000d) variations in BeX systems that we propose are a function of the formation and depletion of the rapidly-rotating Be star's equatorial disc. We compile a list of the 7 different types of super-orbital modulations now identified in interacting binaries, based on their observed characteristics and likely physical origin.

show abstract

Observational properties of accretion discs: Precessing and warped?

Cited by 25 publications

References 39 publications

Discovery of long-term superorbital periodicities in the pseudo-transient LMXBs: IGR J17098−3628 and EXO 0748−676

Discovery of long-term superorbital periodicities in the pseudo-transient LMXBs: IGR J17098−3628 and EXO 0748−676

Very long-term X-ray variations in LMXBs: solar cycle-like variations in the donor?

Long-Term Optical∕X-ray Variability of CVs, LMXBs and BeX Sources

Contact Info

Product

Resources

About