Related papers: Ring Formation in Protoplanetary Disks Driven by a…
Rings and gaps are commonly observed in the dust continuum emission of young stellar disks. Previous studies have shown that substructures naturally develop in the weakly ionized gas of magnetized, non-ideal MHD disks. The gas rings are…
We numerically study the origin of the multi-armed spiral structure observed in the circumnuclear gaseous mini-disks of nearby galaxies. We show that the presence of dust in such disks and its interaction with the gravitationally stable…
The discovery of wide-orbit giant exoplanets has posed a challenge to our conventional understanding of planet formation by coagulation of dust grains and planetesimals, and subsequent accretion of protoplanetary disk gas. As an alternative…
Protoplanetary discs are made of gas and dust orbiting a young star. They are also the birth place of planetary systems, which motivates a large amount of observational and theoretical research. In these lecture notes, I present a review of…
Recent high angular resolution observations of protoplanetary disks at different wavelengths have revealed several kinds of structures, including multiple bright and dark rings. Embedded planets are the most used explanation for such…
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…
Vortex rings are remarkably stable structures occurring in numerous systems: for example in turbulent gases, where they are at the origin of weather phenomena [1]; in fluids with implications for biology [2]; in electromagnetic discharges…
Observations of protoplanetary discs have revealed dust rings which are likely due to the presence of pressure bumps in the disc. Because these structures tend to trap drifting pebbles, it has been proposed that pressure bumps may play an…
Misalignments between the orbital planes of planets and the equatorial planes of their host stars have been observed in our solar system, in transiting exoplanets, and in the orbital planes of debris discs. We present a mechanism that…
Spirals in galaxies have long been thought to be caused by gravitational instability in the stellar component of the disk, but discerning the precise mechanism had proved elusive. Tidal interactions, and perhaps bars, may provoke some…
Gravitational instability (GI) has long been considered a viable pathway for giant planet formation in protoplanetary disks (PPDs), especially at wide orbital separations or around low-mass stars where core accretion faces significant…
The streaming instability, a promising mechanism to drive planetesimal formation in dusty protoplanetary discs, relies on aerodynamic drag naturally induced by the background radial pressure gradient. This gradient should vary in disks, but…
We study the orbital evolution and mass growth of protoplanets with masses $M \in [0.1-8]$~M$_\oplus$ in the vicinity of a dusty ring, using three-dimensional numerical simulations with a two-fluid model and nested-meshes. We find two…
We perform a three-dimensional nonideal magnetohydrodynamic simulation of a strongly magnetized cloud core and investigate the complex structure caused by the interchange instability. This is the first simulation that does not use a central…
Protoplanetary disks are prone to several hydrodynamic instabilities. One candidate, Convective Overstability (COS), can drive radial semi-convection that may influence dust dynamics and planetesimal formation. However, the COS has…
Gravitational instability is one of considerable mechanisms to explain the formation of giant planets. We study the gravitational stability for the protoplanetary disks around a protostar. The temperature and Toomre's Q-value are calculated…
A notable challenge of planet formation is to find a path to directly form planetesimals from small particles. We aim to understand how drifting pebbles pile up in a protoplanetary disk with a non-uniform turbulence structure. We consider a…
In this article, we proceed to study convection as a possible factor of episodic accretion in protoplanetary disks. Within the model presented in Article~I, the accretion history is analyzed at different rates and areas of matter inflow…
It is generally thought that protoplanetary disks embedded in envelopes are more massive and thus more susceptible to gravitational instabilities (GIs) than exposed disks. We present three-dimensional radiative hydrodynamics simulations of…
In this paper we present the global baroclinic instability as a source for vigorous turbulence leading to angular momentum transport in Keplerian accretion disks. We show by analytical considerations and three-dimensional radiation hydro…