相关论文: Collisions between equal sized ice grain agglomera…

Collisions between aggregates with different histories and compositions are expected to be commonplace in dynamically active protoplanetary discs. Nonetheless, relatively little is known about how collisions themselves may contribute to the…

Due to the gravitational influence of density fluctuations driven by magneto-rotational instability in the gas disk, planetesimals and protoplanets undergo diffusive radial migration as well as changes in other orbital properties. The…

The pairwise collisional growth of dust aggregates consisting submicron-sized grains is the first step of the planet formation, and understanding the collisional behavior of dust aggregates is therefore essential. It is known that the main…

We study close encounters involving massive main sequence stars and the evolution of the exotic products of these encounters as common--envelope systems or possible hypernova progenitors. We show that parabolic encounters between low-- and…

We develop a formalism for calculating probabilities for the outcomes of stellar dynamical interactions, based on results from $N$-body scattering experiments. We focus here on encounters involving up to six particles and calculate…

In this work, we apply a soft-sphere discrete element method (SSDEM) within the PKDGRAV N-body integrator to investigate the formation of planetesimal systems through the gravitational collapse of clouds of super-particles. Previously…

We calculate the physical structure of protoplanetary disks by evaluating the gas density and temperature self-consistently and solving separately for the dust temperature. The effect of grain growth is taken into account by assuming a…

There are two popular ways to speed up simulations of planet formation via increasing the collision probability: ({\it i}) confine motion to 2D, ({\it ii}) artificially enhance the physical radii of the bodies by an expansion factor. In…

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 effects of purely elastic collisions on the dynamics of heavy inertial particles is investigated in a three-dimensional random incompressible flow. It is shown that the statistical properties of inter-particle separations and relative…

We show that if comets (or any small icy planetesimals such as Kuiper belt objects) are composed of pebble piles, their internal radiogenic as well as geochemical heating results in considerably different evolutionary outcomes compared to…

It is unknown how far dust growth can proceed by coagulation. Obstacles to collisional growth are the fragmentation and bouncing barriers. However, in all previous simulations of the dust-size evolution in protoplanetary disks, only the…

Despite their very low surface gravities, the surfaces of asteroids and comets are covered by granular materials - regolith - that can range from a fine dust to a gravel-like structure of varying depths. Understanding the dynamics of…

In laboratory experiments we determine the mass gain and loss in central collisions between cm to dm-size SiO2 dust targets and sub-mm to cm-size SiO2 dust projectiles of varying mass, size, shape, and at different collision velocities up…

We use numerical simulations to examine the structure of merger remnants resulting from collisions of gas-rich spiral galaxies. When the gas fraction of the progenitors is small, the remnants structurally and kinematically resemble…

The cores of wide-orbit giant planets can form via pebble accretion if large planetesimals form in the outer regions of protoplanetary discs at sufficiently early times. Streaming instability simulations support mass distributions…

Solid particles in protoplanetary disks that are sufficiently super-solar in metallicity overcome turbulence generated by vertical shear to gravitationally condense into planetesimals. Super-solar metallicities result if solid particles…

It is difficult to imagine a planet formation model that does not at some stage include a gravitationally unstable disc. Initially unstable gas-dust discs may form planets directly, but the high surface density required has motivated the…

The growth of planetesimals is an essential step in planet formation. Decimetre-size dust agglomerates mark a transition point in this growth process. In laboratory experiments we simulated the formation, evolution, and properties of…

We investigate the orbital evolution of planetesimals in a self-gravitating circumstellar disc in the size regime ($\sim 1-5000$ km) where the planetesimals behave approximately as test particles in the disc's non-axisymmetric potential. We…