Related papers: Accretion disc dynamics in extreme mass ratio comp…
We study the accretion on to the neutron star in Be/X-ray binaries, using a 3D SPH code and the data imported from a simulation by \citet{oka2} for a coplanar system with a short period ($P_{\rm orb}=24.3 \rm{d}$) and a moderate…
We study the dynamical effects of gravitational focusing by a binary companion on winds from late-type stars. In particular, we investigate the mass transfer and formation of accretion disks around the secondary in detached systems…
We study non-axisymmetric structure of accretion discs in Be/X-ray binaries, performing three dimensional Smoothed Particle Hydrodynamics simulations for a coplanar system with a short period and a moderate eccentricity. We find that ram…
We explore the hardening of a massive black hole binary embedded in a circum-binary gas disc when the binary and the gas are coplanar and the gas is counter-rotating. The secondary black hole, revolving in the direction opposite to the gas,…
We investigate the accretion geometry in neutron star low-mass X-ray binaries (LMXBs) in the hard spectral state. It is commonly accepted that, for low mass transfer rates, an advection-dominated accretion flow (ADAF) is present in the…
The presence of planets in binary systems poses interesting problems for planet formation theories, both in cases where planets must have formed in very compact discs around the individual stars and where they are located near the edge of…
We consider misaligned accretion discs formed after tidal disruption events occurring when a star encounters a supermassive rotating black hole. We use the linear theory of warped accretion discs to find the disc shape when the stream…
The arising of turbulence in gas-dynamic (non-magnetic) accretion disks is a major issue of modern astrophysics. Such accretion disks should be stable against the turbulence generation, in contradiction to observations. Searching for…
In recent years, many wide orbit circumbinary giant planets have been discovered; some of these may have formed by gravitational fragmentation of circumbinary discs. The aim of this work is to investigate the lower mass limit for…
We describe some recent nonlinear three dimensional hydrodynamic simulations of accretion discs in binary systems where the orbit is circular and not necessarily coplanar with the disc midplane. The calculations are relevant to a number of…
We investigate the role of the eccentric disc resonance in systems with mass ratios q greater than 1/4, and demonstrate the effects that changes in the mass flux from the secondary star have upon the disc radius and structure. The addition…
Accretion discs at sub-pc distances around supermassive black holes are likely to cool rapidly enough that self-gravity results in fragmentation. Here, we use high-resolution hydrodynamic simulations of a simplified disc model to study how…
We carry out numerical simulations of circumbinary discs, solving the viscous hydrodynamics equations on a polar grid covering an extended disc outside the binary co-orbital region. We use carefully controlled outer boundary conditions and…
We study a warping instability of a geometrically thin, non-self-gravitating, circumbinary disk around young binary stars on an eccentric orbit. Such a disk is subject to both the tidal torques due to a time-dependent binary potential and…
Supermassive black hole binaries are likely to accrete interstellar gas through a circumbinary disk. Shortly before merger, the inner portions of this circumbinary disk are subject to general relativistic effects. To study this regime, we…
The typical product of the star formation process is a binary star. Binaries have provided the first dynamical measures of the masses of pre-main-sequence (PMS) stars, providing support for the calibrations of PMS evolutionary tracks.…
We study the three-dimensional evolution of a viscous protoplanetary disc which accretes gas material from a second protoplanetary disc during a close encounter in an embedded star cluster. The aim is to investigate the capability of the…
Simulations of the collapse and fragmentation of turbulent molecular clouds and dense young clusters show that encounters between disc-surrounded stars are relatively common events which should significantly influence the resulting disc…
We present a two-dimensional grid-based hydrodynamic simulation of a thin, viscous, locally-isothermal corotating disk orbiting an equal-mass Newtonian binary point mass on a fixed circular orbit. We study the structure of the disk after…
We investigate the formation and evolution of misaligned accretion discs around the secondary component of a binary through mass transfer driven by Kozai-Lidov oscillations of the circumprimary disc's eccentricity and inclination. We…