相关论文: Breaking through: The effects of a velocity distri…
We study stability of a dust layer in a gaseous disc subject to the linear axisymmetric perturbations. Instead of considering single-size particles, however, the population of dust particles is assumed to consist of two grain species. Dust…
The formation of planetesimals in the early Solar System is hardly understood, and in particular the growth of dust aggregates above millimeter sizes has recently turned out to be a difficult task in our understanding [Zsom et al. 2010,…
The coagulation of dust particles under the conditions in protoplanetary disks is investigated. The study focuses on the repulsive electrostatic barrier against growth of charged dust grains. Taking into account the photoelectric effect…
After 25 years of laboratory research on protoplanetary dust agglomeration, a consistent picture of the various processes that involve colliding dust aggregates has emerged. Besides sticking, bouncing and fragmentation, other effects, like,…
In this paper, we study the effect of MHD turbulence on the dynamics of dust particles in protoplanetary disks. We vary the size of the particles and relate the dust evolution to the turbulent velocity fluctuations. We performed numerical…
We use a new multiannulus planetesimal accretion code to investigate the evolution of a planetesimal disk following a moderately close encounter with a passing star. The calculations include fragmentation, gas and Poynting-Robertson drag,…
(abridged) In the core accretion scenario for the formation of planetary rocky cores, the first step toward planet formation is the growth of dust grains into larger and larger aggregates and eventually planetesimals. Although dust grains…
The degree of coupling between the gas and the magnetic field during the collapse of a core and the subsequent formation of a disk depends on the assumed dust size distribution. We study the impact of grain-grain coagulation on the…
Over the past years the processes involved in the growth of planetesimals have extensively been studied in the laboratory. Based on these experiments, a dust-aggregate collision model was developed upon which computer simulations were based…
The rapid depletion of dust particles in protoplanetary disks limits the time available for planetesimal formation, as solids are typically accreted onto the central star before dust particles can undergo substantial growth. Dust traps…
We investigate dust dynamics and evolution during the formation of a protostellar accretion disk around intermediate mass stars via 2D numerical simulations. Using three different detailed dust models, compact spherical particles, fractal…
The early planetesimal growth proceeds through a sequence of sticking collisions of dust agglomerates. Very uncertain is still the relative velocity regime in which growth rather than destruction can take place. The outcome of a collision…
We study the dynamics and growth of dust particles in circumstellar disks of different masses that are prone to gravitational instability during the critical first Myr of their evolution. The dust component is made up of two different…
Aims. We numerically investigated dust enrichment and growth during the initial stages of protoplanetary disk formation. A particular objective was to determine the effects of various growth barriers, mimicked by imposing a series of upper…
The formation of planetesimals in protoplanetary disks due to collisional sticking of smaller dust aggregates has to face at least two severe obstacles, namely the rapid loss of material due to radial inward drift and particle fragmentation…
First, we have ensured that spherical nonrotating collisionless systems collapse with almost retaining spherical configurations during initial contraction phases even if they are allowed to collapse three-dimensionally. Next, on the…
In protoplanetary disks, the distribution and abundance of small (sub)micron grains are important for a range of physical and chemical processes. For example, they dominate the optical depth at short wavelengths and their surfaces are the…
By performing $N$-body simulations, we investigated fundamental processes of collisions between dust aggregates composed of submicron-sized icy dust monomers. We examined the mass distribution of fragments in the collisional outcomes in a…
Context: The streaming instability (SI) is a leading candidate for reaching solid densities sufficient to trigger the gravitational collapse needed for the formation of planetesimals. However, dust growth barriers appear to impede the…
We investigate the effects of stellar evolution and dust on measurements of stellar velocity dispersion in mergers of disk galaxies. $N$-body simulations and radiative transfer analysis software are used to obtain mass-weighted and…