Related papers: Planetesimal drift in eccentric disks: possible ou…
Dust particles in protoplanetary disks, lacking support from pressure, rotate at velocities exceeding those of the surrounding gas. Consequently, they experience a head-wind from the gas that drives them toward the central star. Radial…
The circular velocities of the inner region of disk galaxies are predicted by standard physics but velocities beyond the stellar disks are not consistent with Newtonian physics if the material there is in stable circular orbits. However,…
Observations of structure in circumstellar debris discs provide circumstantial evidence for the presence of massive planets at large (several tens of au) orbital radii, where the timescale for planet formation via core accretion is…
Studies of planet migration derived from disc planet interactions began before the discovery of exoplanets. The potential importance of migration for determining orbital architectures being realised, the field received greater attention…
We investigate the possibility of erosion of planetesimals in a protoplanetary disk. We use theory and direct numerical simulations (Lattice Boltzmann Method) to calculate the erosion of large -- much larger than the mean-free-path of gas…
There is evidence for the existence of massive planets at orbital radii of several hundred AU from their parent stars where the timescale for planet formation by core accretion is longer than the disc lifetime. These planets could have…
We study the conditions for collisions between planetesimals to be accretional or disruptive in turbulent disks, through analytical arguments based on fluid dynamical simulations and orbital integrations. In turbulent disks, the velocity…
Recent exoplanet observations have revealed a diversity of exoplanetary systems, which suggests the ubiquity of radial planetary migration. One powerful known mechanism of planetary migration is planetesimal-driven migration (PDM), which…
In the core accretion scenario, gas giant planets are formed form solid cores with several Earth masses via gas accretion. We investigate the formation of such cores via collisional growth from kilometer-sized planetesimals in turbulent…
The formation of planetesimals is a necessary step in the formation of planets. While several mechanisms have been proposed, a local dust-to-gas ratio above unity is a strong requirement to trigger the collapse of pebble clouds into…
We study how the interaction between the streaming instability and intrinsic gas-phase turbulence affects planetesimal formation via gravitational collapse in protoplanetary disks. Turbulence impedes the formation of particle clumps by…
Planet formation via core accretion involves the growth of solids that can accumulate to form planetary cores. There are a number of barriers to the collisional growth of solids in protostellar discs, one of which is the drift, or metre,…
Models of dust coagulation and subsequent planetesimal formation are usually computed on the backdrop of an already fully formed protoplanetary disk model. At the same time, observational studies suggest that planetesimal formation should…
The exoplanet diversity has been linked to the disc environment in which they form, where the host star metallicity and the formation pathways play a crucial role. In the context of the core accretion paradigm, the initial stages of planet…
The first stages of planet formation take place in protoplanetary disks that are largely made up of gas. Understanding how the gas affects planetesimals in the protoplanetary disk is therefore essential. In this paper, we discuss whether or…
Planetesimal belts are invoked to explain the prolonged existence of debris disks. Important parameters to model their collisional evolution and to compute the dust production rate are the intrinsic probability of collision $P_i$ and the…
Planetesimals form in gas-rich protoplanetary disks around young stars. However, protoplanetary disks fade in about 10 Myr. The planetesimals (and also many of the planets) left behind are too dim to study directly. Fortunately, collisions…
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$_\oplus$)…
We study the migration of solid bodies in turbulent protoplanetary accretion discs by means of global MHD simulations. The bodies range in size from 5 centimetres up to 1 metre, and so include objects whose migration is expected to be the…
Forming planetesimals from pebbles is a major challenge in our current understanding of planet formation. In a protoplanetary disk, pebbles drift inward near the disk midplane via gas drag and they may enter a dead zone. In this context, we…