Precessing warped accretion discs in X-ray binaries

Details Precessing warped accretion discs in X-ray binaries Precessing warped accretion discs in X-ray binaries

2000-09-17

arxiv.org/abs/astro-ph/0009264v1

Mon.Not.Roy.Astron.Soc. 320 (2001) 485

Astronomy and Astrophysics

Astrophysics

20 pages, 10 figures, to be published in MNRAS

Scientific paper

10.1046/j.1365-8711.2001.04011.x

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 `super-orbital' 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 by Wijers & 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.

Affiliated with

Also associated with

No associations

Rating

Precessing warped accretion discs in X-ray binaries does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Precessing warped accretion discs in X-ray binaries, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Precessing warped accretion discs in X-ray binaries will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-249741