Related papers: The Accretion Disc Dynamo in the Solar Nebula
Accretion discs are fundamental to much of astronomy. They can occur around stars both young and old, around compact objects they provide a window into the extremes of physics, and around supermassive black holes in galaxy centres they…
Protoplanetary discs exhibit a diversity of gaps and rings of dust material, believed to be a manifestation of pressure maxima commonly associated with an ongoing planet formation and several other physical processes. Hydrodynamic disc…
We show that in realistic cases of accretion in active galactic nuclei or stellar-mass X-ray binaries, the Lense-Thirring effect breaks the central regions of tilted accretion discs around spinning black holes into a set of distinct planes…
For many astrophysical sources with jets, there is evidence for the contemporaneous presence of disks. In contrast, pulsars such as the Crab and Vela show jets but have not yet revealed direct evidence for accretion disks. Here we show that…
We review recent observational and theoretical results on the relationship between circumstellar accretion disks and jets in young stellar objects. We then present a theoretical framework that interprets jets as accretion-powered,…
Millimeter sized dust grains experience radial velocities exceeding the gas velocities by orders of magnitude. The viscous evolution of the accretion disk adds disk material onto the central star's convective envelope, influencing its…
We present a numerical model for the evolution of a protostellar disc that has formed self-consistently from the collapse of a molecular cloud core. The global evolution of the disc is followed for several million years after its formation.…
Using Spitzer Space Telescope photometric observations of the eclipsing, interacting binary WZ Sge, we have discovered that the accretion disk is far more complex than previously believed. Our 4.5 and 8 micron time series observations…
(Abridged) Numerical magnetohydrodynamic (MHD) simulations of a turbulent solar nebula are used to study the growth of dust mantles swept up by chondrules. A small neighborhood of the solar nebula is represented by an orbiting patch of gas…
Structure of a quasi-stationary stellar cluster is modelled assuming that it is embedded in the gravitational field of a super-massive black hole. Gradual orbital decay of stellar trajectories is caused by the dissipative interaction with…
We analyse simulations of turbulent, magnetised molecular cloud cores focussing on the formation of Class 0 stage protostellar discs and the physical conditions in their surroundings. We show that for a wide range of initial conditions…
We show that for young stars which are still accreting and for which measurements of stellar age, disc mass and accretion rate are available, nominal disc age (Disc Age = Disc Mass / Accretion Rate) is approximately equal to the stellar…
When neutron stars accrete matter from a companion star, this matter forms a disc around them and eventually falls on their surface. Here, the fuel can ignite into bright flashes called Type I bursts. Theoretical calculations based on…
In this paper, we further develop the model for the migration of planets introduced in Del Popolo et al. (2001). We first model the protoplanetary nebula as a time-dependent accretion disc and find self-similar solutions to the equations of…
We suggest that part of the infalling material during the core-collapse of a massive star goes into orbit around the compact core to form a hot, dense, centrifugally-supported accretion disk whose evolution is strongly influenced by…
We present the results of qualitative consideration of possible changes occurring during the transition from the hot accretion disc to the cool one. We argue the possible existence of one more type of spiral density waves in the inner part…
Abridged: Recent simulations have explored different ways to form accretion disks around low-mass stars. We aim to present observables to differentiate a rotationally supported disk from an infalling rotating envelope toward deeply embedded…
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…
We present time-dependent models of the accretion disks created during compact object mergers, focusing on the energy available from accretion at late times and the composition of the disk and its outflows. We calculate the dynamics near…
Accretion disks around compact objects are expected to enter an unstable phase at high luminosity. One instability may occur when the radiation pressure generated by accretion modifies the disk viscosity, resulting in the cyclic depletion…