Related papers: Observational Implications of Precessing Protostel…
With the discovery over the last two decades of a large diversity of exoplanetary systems, it is now of prime importance to characterize star-planet interactions and how such systems evolve. We address this question by studying systems…
(Abbreviated) We extend the results of our 2021 paper concerning the problem of tidal evolution of a binary system with a rotating primary component with rotation axis arbitrarily inclined with respect to the orbital plane. Only the…
We investigate the evolution of a disk wind into a collimated jet under the influence of magnetic diffusivity, assuming that the turbulent pattern in the disk will also enter the disk corona and the jet. Using the ZEUS-3D code in the…
Context. Multiple mechanisms are known to give rise to turbulence in protoplanetary disks, which facilitates the accretion onto the central star. Small dust particles that are well coupled to the gas undergo diffusion due to this turbulent…
Protoplanetary disks are likely to be threaded by a weak net flux of vertical magnetic field that is a remnant of the much larger fluxes present in molecular cloud cores. If this flux is approximately conserved its dynamical importance will…
Superorbital periods are observed in the optical light curves of many Be/X-ray binaries yet their origin has remained somewhat elusive. We suggest that precession of the spin axis of the Be star can drive superorbital periods, particularly…
The question whether the interaction of a circumbinary disc with the central binary system leads to shrinking or expansion of the binary orbit has attracted considerable interest as it impacts the evolution of binary black holes and stellar…
We present an analytical and numerical study of a system composed of a stellar binary pair and a massless, locally isothermal viscous accretion disk that is coplanar to the binary orbital plane. Analytically, we study the effect of the…
The formation of circumstellar disks is investigated using three-dimensional resistive magnetohydrodynamic simulations, in which the initial prestellar cloud has a misaligned rotation axis with respect to the magnetic field. We examine the…
Observations reveal protoplanetary discs being perturbed by flyby candidates. We simulate a scenario where an unbound perturber, i.e., a flyby, undergoes an inclined grazing encounter, capturing material and forming a second-generation…
Observations of accreting black holes often provoke suggestions that their jets precess. The precession is usually supposed to result from a combination of the Lense-Thirring effect and accretion disc viscosity. We show that this is…
I review the processes that shape the evolution of protoplanetary discs around young, solar-mass stars. I first discuss observations of protoplanetary discs, and note in particular the constraints these observations place on models of disc…
Newly formed stars are often observed to possess circumstellar disks, from which mass continues to be accreted onto the star and fed into outflowing jets, and which eventually may evolve into dusty debris disks and planetary systems. Recent…
The dynamical evolution of short-period low-mass binary stars (with mass $M < 1.5M_{\odot}$, from formation to the late main-sequence, and with orbital periods less than $\sim$10 days) is strongly influenced by tidal dissipation. This…
The radiation-driven warping instability discovered by Pringle holds considerable promise as the mechanism responsible for producing warped, precessing accretion disks in X-ray binaries. This instability is an inherently global mode of the…
The role of convection in the gas-dust accretion disk around a young star is studied. The evolution of a Keplerian disk is modeled using the Pringle equation, which describes the time variations of the surface density under the action of…
The precession of astrophysical jets produced by active-galactic nuclei is likely related to the dynamics of the accretion disks surrounding the central supermassive black holes (BHs) from which jets are launched. The two main mechanisms…
We review the models and results of simulations of self-gravitating, gaseous protoplanetary disks in binary star systems. These models have been calculated by three different groups with three different computational methods, two…
Astrophysical fluid bodies that orbit close to one another induce tidal distortions and flows that are subject to dissipative processes. The spin and orbital motions undergo a coupled evolution over astronomical timescales, which is…
We analyze the dynamics of individual kilometer-size planetesimals in circumstellar orbits of a tight binary system. We include both the gravitational perturbations of the secondary star and a non-linear gas drag stemming from an eccentric…