Precessing warped accretion discs in X‐ray binaries

By Gordon I. Ogilvie, Guillaume Dubus. 2000

190 citations recorded by the source corpus.

We study the radiation-driven warping of accretion discs in the context of X-ray binaries. The latest evolutionary equations are adopted, which extend the classical alpha theory to time-dependent thin discs with non-linear warps. We also develop accurate, analytical expressions for the tidal torque and the radiation torque, including self-shadowing. We investigate the possible non-linear dynamics of the system within the framework of bifurcation theory. First, we re-examine the stability of an initially flat disc to the Pringle instability. Then we compute directly the branches of non-linear solutions representing steadily precessing discs. Finally, we determine the stability of the non-linear solutions. Each problem involves only ordinary differential equations, allowing a rapid, accurate and well-resolved solution. We find that radiation-driven warping is probably not a common occurrence in low-mass X-ray binaries. We also find that stable, steadily precessing discs exist for a narrow range of parameters close to the stability limit. This could explain why so few systems show clear, repeatable ‘superorbital’ variations. The best examples of such systems, Her X-1, SS 433 and LMC X-4, all lie close to the stability limit for a reasonable choice of parameters. Systems far from the stability limit, including Cyg X-2, Cen X-3 and SMC X-1, probably experience quasi-periodic or chaotic variability as first noticed recently by Wijers and Pringle. We show that radiation-driven warping provides a coherent and persuasive framework but that it does not provide a generic explanation for the long-term variabilities in all X-ray binaries.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/600c6c130b8de4a911f2fe6266f1d827f186832d

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In Astronomy and Astrophysics

1. G. Lodato
2. T. Rogers
3. H. Lau
4. Jim N. McElwaine
5. J. Gladstone
6. Bing Zhang
7. U. Exeter
8. Joshua S. Bloom

In Instrumentation

1. U. Exeter
2. Joshua S. Bloom
3. A. King
4. J. E. Pringle
5. H. Lau
6. D. Lin
7. M. Begelman
8. C. Heinke

Citations in the corpus

• On the diffusive propagation of warps in thin accretion discs (2010, background): “(10) Taking account of large values ofα, but still for small amplitude warps, the expected relation is given by (cf. Ogilvie & Dubus2001, Eq.”
• The nature of SS433 and the ultraluminous X-ray sources (2006, background): “However, it is important to realize that regular precession is not generic to the ULX picture we have set out (Wijers & Pringle 1999; Ogilvie & Dubus 2001).”
• INTERNAL GRAVITY WAVES IN MASSIVE STARS: ANGULAR MOMENTUM TRANSPORT (2013, background): “The origin of such warped disks is unclear, although there have been many theories (Bardeen & Petterson 1975; Petterson 1977; Papaloizou & Pringle 1983; Papaloizou & Lin 1995; Papaloizou & Terquem 1995; Pringle 1996; Ogilvie & Dubus 2001).”
• THE SWIFT/BAT HARD X-RAY TRANSIENT MONITOR (2006, background): “…galaxy NGC 4388, which is known to have variations in hard X rays on the 3-6 month time scale (Fedorova et al. 2011); the HMXB/µQuasar SS 433, which is observed in BAT to follow the 164-day superorbital period (Ogilvie & Dubus 2001); and the LMXB/NS and thermonuclear burster KS 1741−293 (AX J1744.”
• WATCHDOG: A COMPREHENSIVE ALL-SKY DATABASE OF GALACTIC BLACK HOLE X-RAY BINARIES (2015, result): “A much longer periodicity has also been reported by Ogilvie & Dubus (2001), thought to be related to cyclic transitions between a flat and warped disk, similar to what is observed in Cyg X-1 and LMC X-3.”