Astronomy and Astrophysics – Astrophysics
Scientific paper
2007-01-02
Mon.Not.Roy.Astron.Soc.376:89-97,2007
Astronomy and Astrophysics
Astrophysics
17 pages, 9 figures, 7 in colour. Accepted for publication in MNRAS. Plain article formatting to get round arXiv problems with
Scientific paper
10.1111/j.1365-2966.2007.11437.x
An analysis is presented of a numerical investigation of the dynamics and geometry of accretion discs in binary systems with mass ratios q < 0.1, applicable to ultra-compact X-ray binaries, AM CVn stars and very short period cataclysmic variables. The steady-state geometry of the disc in the binary reference frame is found to be quite different from that expected at higher mass ratios. For q ~ 0.1, the disc takes on the usual elliptical shape, with the major axis aligned perpendicular to the line of centres of the two stars. However, at smaller mass ratios the elliptical gaseous orbits in the outer regions of the disc are rotated in the binary plane. The angle of rotation increases with gas temperature, but is found to vary inversely with q. At q = 0.01, the major axis of these orbits is aligned almost parallel to the line of centres of the two stars. These effects may be responsible for the similar disc structure inferred from Doppler tomography of the AM CVn star GP Com (Morales-Rueda et al. 2003), which has q = 0.02. The steady-state geometry at low mass ratios is not predicted by an inviscid, restricted three-body model of gaseous orbits; it is related to the effects of tidal-viscous truncation of the disc near the Roche lobe boundary. Since the disc geometry can be inferred observationally for some systems, it is proposed that this may offer a useful diagnostic for the determination of mass ratios in ultra-compact binaries.
No associations
LandOfFree
Accretion disc dynamics in extreme mass ratio compact 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 Accretion disc dynamics in extreme mass ratio compact binaries, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Accretion disc dynamics in extreme mass ratio compact binaries will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-188961