Related papers: Mass Flow and Accretion through gaps in Accretion …
We explore in situ formation and subsequent evolution of close-in super-Earths and mini-Neptunes. We adopt a steady-state inner protoplanetary gas disc structure that arises from viscous accretion due to the magneto-rotational instability…
Planet formation occurs over a few Myr within protoplanetary discs of dust and gas, which are often assumed to evolve in isolation. However, extended gaseous structures have been uncovered around many protoplanetary discs, suggestive of…
We examine the effect of an accretion disc on the orbits of stars in the central star cluster surrounding a central massive black hole by performing a suite of 39 high-accuracy direct N-body simulations using state-of-the art software and…
The processes of planet formation and migration depend intimately on the interaction between planetesimals and the gaseous disks in which they form. The formation of gaps in the disk can severely limit the mass of the planet and its…
The source of viscosity in astrophysical accretion flows is still a hotly debated issue. We investigate the contribution of convective turbulence to the total viscosity in a self-consistent approach, where the strength of convection is…
Recent surveys have revealed that protoplanetary discs typically have dust masses that appear to be insufficient to account for the high occurrence rate of exoplanet systems. We demonstrate that this observed dust depletion is consistent…
We perform numerical simulations of a disc-planet system using various grid-based and smoothed particle hydrodynamics (SPH) codes. The tests are run for a simple setup where Jupiter and Neptune mass planets on a circular orbit open a gap in…
I review recent progresses in the dynamics and the evolution of self-gravitating accretion discs. Accretion discs are a fundamental component of several astrophysical systems on very diverse scales, and can be found around supermassive…
We have carried out and analyzed a set of axisymmetric MHD simulations of the evolution of a turbulent/diffusive accretion disc around an initially unmagnetized star. The disc is initially threaded by a weak magnetic field where the…
Nascent planets are thought to lose angular momentum (AM) to the gaseous protoplanetary disk via gravitational interactions, leading to inward migration. A similar migration process also applies to stellar-mass black holes (BHs) embedded in…
A star acquires much of its mass by accreting material from a disc. Accretion is probably not continuous but episodic. We have developed a method to include the effects of episodic accretion in simulations of star formation. Episodic…
(Abridged) We consider models of gas giant planets forming in protoplanetary disks consisting of solid cores with gaseous envelopes in contact with their critical Hill spheres while accreting gas from the surrounding disk.We suppose the…
We present computational results showing eccentricity growth in the inner portions of a protoplanetary disc. We attribute this to the evolving surface density of the disc. The planet creates a gap, which adjusts the balance between the 3:1…
Axisymmetric dust rings containing tens to hundreds of Earth masses of solids have been observed in protoplanetary discs with (sub-)millimetre imaging. Here, we investigate the growth of a planetary embryo in a massive (150M$_\oplus$)…
The formation history of Jupiter has been of interest due to its ability to shape the solar system's history. Yet little attention has been paid to the formation and growth of Saturn and the other giant planets. Here, we explore the…
Upcoming studies of extrasolar gas giants will give precise insights into the composition of planetary atmospheres with the ultimate goal to link it to the formation history of the planet. Here, we investigate how drifting and evaporating…
We present a 3-D ideal MHD simulation of magnetospheric accretion onto a non-rotating star. The accretion process unfolds with intricate 3-D structures driven by various mechanisms. First, the disc develops filaments at the magnetospheric…
Pebble accretion offers an efficient pathway to form planets, driven by a constant supply of inward drifting mass and an accretion efficiency enhanced by gas drag. While most studies assume a single pebble size (monodisperse), real discs…
We present time-dependent simulations of a two-phase accretion flow around a black hole. The accretion flow initially is composed of an optically thick and cool disc close to the midplane, while on top and below the disc there is a hot and…
Much recent work on planet formation has focused on the growth of planets by accretion of grains whose aerodynamic properties make them marginally coupled to the nebular gas, a theory commonly referred to as "pebble accretion". While pebble…