Related papers: Spiral Density Enhancements in Be Binary Systems

The interaction of a massive binary and a non-self-gravitating circumbinary accretion disc is considered. The shape of the stationary twisted disc produced by the binary is calculated. It is shown that the inner part of the disc must lie in…

Recent observations of strikingly well-defined spirals in the circumstellar envelopes of asymptotic giant branch (AGB) stars point to the existence of binary companions in these objects. In the case of planet or brown dwarf mass companions,…

We present the results of non linear, hydrodynamic simulations, in three dimensions, of the tidal perturbation of accretion discs in binary systems where the orbit is circular and not necessarily coplanar with the disc mid-plane. The…

Aside from the grand-design stellar spirals appearing in the disk of M81, a pair of stellar spiral arms situated well inside the bright bulge of M81 has been recently discovered by Kendall et al. (2008). The seemingly unrelated pairs of…

We present the results of an H-alpha monitoring campaign on the BeXRB and microquasar system LS I +61 303. We use radial velocity measurements of HeI lines in our spectra to re-evaluate the orbital elements and to better establish the time…

We examine the growth of eccentricities of a population of particles with initially circular orbits around a central massive body. Successive encounters between pairs of particles increase the eccentricities in the disk on average. As long…

Using self-consistent three-dimensional (3D) N-body simulations, we investigate the physical properties of non-axisymmetric features in a disk galaxy created by a tidal interaction with its companion. The primary galaxy consists of a…

We consider a model for the cyclic brightness variations of a young star with a low-mass companion that accretes matter from the remnants of a protostellar cloud. At small inclinations of the binary orbit to the line of sight, the streams…

The study of the stability of massive gaseous disks around a star in a non-isolated context is not a trivial issue and becomes a more complicated task for disks hosted by binary systems. The role of self-gravity is thought to be…

Triple stellar systems allow us to study stellar processes that cannot be attained in binary stars. The evolutionary phases in which the stellar members undergo mass exchanges can alter the hierarchical layout of these systems. Yet, the…

We study how well the complex gas velocity fields induced by massive spiral arms are modelled by the hydrodynamical simulations we used to constrain the dark matter fraction in nearby spiral galaxies (Kranz et al. 2001, 2003). More…

Warped accretion discs are expected in many protostellar binary systems. In this paper, we study the long-term evolution of disc warp and precession for discs with dimensionless thickness $H/r$ larger than their viscosity parameter…

Previous work has shown that interactions between a central binary system and a circumbinary disc (CBD) can lead to the binary orbit either shrinking or expanding, depending on the properties of the disc. In this work, we perform…

We explore test particle orbits in the orbital plane of eccentric stellar binary systems, searching for ``invariant loops'': closed curves that change shape periodically as a function of binary orbital phase as the test particles in them…

Debris disc analysis and modelling provide crucial information about the structure and the processes at play in extrasolar planetary systems. In binary systems, this issue is more complex because the disc should in addition respond to the…

The locations of the fully despun, double synchronous end states of tidal evolution are derived for spherical components. With the exception of nearly equal-mass binaries, binary asteroid systems are in the midst of lengthy tidal…

One of the striking discoveries of protoplanetary disc research in recent years are the spiral arms seen in several transitional discs in polarised scattered light. An interesting interpretation of the observed spiral features is that they…

Short-period binary star systems dissipate orbital energy through tidal interactions that lead to tighter, more circular orbits. When at least one star in a binary has evolved off of the main sequence, orbital circularization occurs for…

The opacity of a spiral disk due to dust absorption influences every measurement we make of it in the UV and optical. Two separate techniques directly measure the total absorption by dust in the disk: calibrated distant galaxy counts and…

The density-wave theory of spiral structure proposes that star formation occurs in or near a spiral-shaped region of higher density that rotates rigidly within the galactic disk at a fixed pattern speed. In most interpretations of this…