Related papers: Forced Eccentricity in Circumbinary Discs
Many post-AGB star binaries are observed to have relatively high orbital eccentricities (up to 0.6). Recently, AC Her was observed to have a polar-aligned circumbinary disk. We perform hydrodynamic simulations to explore the impact of a…
Gravitational coupling between a protoplanetary disc and an embedded eccentric planet is an important, long-standing problem, which has been not yet been conclusively explored. Here we study the torque and associated orbital evolution of an…
Accretion disks around stars, or other central massive bodies, can support long-lived, slowly precessing $m=1$ disturbances in which the fluid motion is nearly Keplerian with non-zero eccentricity. We study such `slow modes' in disks that…
Detections of planets in eccentric, close (separations of ~20 AU) binary systems such as \alpha Cen or \gamma Cep provide an important test of planet formation theories. Gravitational perturbations from the companion are expected to excite…
Eccentric Keplerian discs are believed to be unstable to three-dimensional hydrodynamical instabilities driven by the time-dependence of fluid properties around an orbit. These instabilities could lead to small-scale turbulence, and…
We investigate the structure and evolution of a geometrically thin viscous Keplerian circumbinary (CB) disk, using detailed models of their radiative/convective vertical structure. We use a simplified description for the evolution of the…
We investigate the secular evolution of the orbital semi-major axis and eccentricity due to mass transfer in eccentric binaries, allowing for both mass and angular momentum loss from the system. Adopting a delta function mass transfer rate…
We extend previous studies of the tidal truncation of coplanar disks in binary systems to the more general case of noncoplanar disks. As in the prograde coplanar case, Lindblad resonances play a key role in tidal truncation. We analyze the…
During the process of planet formation, the planet-discs interactions might excite (or damp) the orbital eccentricity of the planet. In this paper, we present two long ($t\sim 3\times 10^5$ orbits) numerical simulations: (a) one (with a…
Whether tidal disruption events (TDEs) circularise or accrete directly as a highly eccentric disc is the subject of current research and appears to depend sensitively on the disc thermodynamics. In a previous paper we applied the theory of…
We explore the evolution of a giant planet that interacts with a circumbinary disc that orbits a misaligned binary by means of analytic models and hydrodynamical simulations. Planet-disc interactions lead to mutual tilt oscillations between…
Much of the parameter space relevant to the evolution of astrophysical circumbinary accretion discs remains unexplored. We have carried out a suite of circumbinary disc simulations surveying both disc thickness and kinematic viscosity,…
We derive analytical expressions for the change in the orbital eccentricity of a binary following a distant encounter with a third star on a hyperbolic or parabolic orbit. To establish the accuracy of these expressions, we present detailed…
We consider the effects of eccentricity on the fragmentation of gravitationally unstable accretion disks, using numerical hydrodynamics. We find that eccentricity does not affect the overall stability of the disk against fragmentation, but…
In this paper, we show that the eccentricity of a planet on an inclined orbit with respect to a disc can be pumped up to high values by the gravitational potential of the disc, even when the orbit of the planet crosses the disc plane. This…
We investigate the effect of a planet on an eccentric orbit on a two dimensional low mass gaseous disk. At a planet eccentricity above the planet's Hill radius divided by its semi-major axis, we find that the disk morphology differs from…
We present the to-date largest parameter space exploration of binaries in circumbinary disks (CBDs), deriving orbital evolution prescriptions for eccentric, unequal mass binaries from our suite of hydrodynamic simulations. In all cases,…
We formulate a local dynamical model of an eccentric disc in which the dominant motion consists of elliptical Keplerian orbits. The model is a generalization of the well known shearing sheet, and is suitable for both analytical and…
We analyze a tilt instability of the orbit of an outer planet in a two planet circumbinary system that we recently reported. The binary is on an eccentric orbit and the inner circumbinary planet is on a circular polar orbit that causes the…
With hydrodynamic simulations we show that a coplanar disc around one component of a binary can be unstable to global tilting when the disc orbits in a retrograde direction relative to the binary. The disc experiences the largest…