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Related papers: TEMPus VoLA: the Timed Epstein Multi-pressure Vess…

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We present Atacama Large Millimeter/submillimeter Array (ALMA) observations of multiple protostar systems in the Perseus molecular cloud previously detected by the Karl G. Jansky Very Large Array (VLA). We observed 17 close ($<$600~AU…

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…

Earth and Planetary Astrophysics · Physics 2013-01-17 Alexander Seizinger , Roland Speith , Wilhelm Kley

The key planet-formation processes in protoplanetary disks remain an active matter of research. One promising mechanism to radially and azimuthally trap millimeter-emitting dust grains, enabling them to concentrate and grow into…

We consider the dynamics of porous icy dust aggregates in a turbulent gas disk and investigate the stability of the disk. We evaluate the random velocity of porous dust aggregates by considering their self-gravity, collisions, aerodynamic…

Earth and Planetary Astrophysics · Physics 2017-06-28 Shugo Michikoshi , Eiichiro Kokubo

Instabilities of the dust layer in a protoplanetary disk are investigated. It is known that the streaming instability develops and dust density concentration occurs in a situation where the initial dust density is uniform. This work…

Earth and Planetary Astrophysics · Physics 2009-05-29 Naoki Ishitsu , Shu-ichiro Inutsuka , Minoru Sekiya

Following Paper I we investigate the properties of atmospheres that form around small protoplanets embedded in a protoplanetary disc by conducting hydrodynamical simulations. These are now extended to three dimensions, employing a spherical…

Earth and Planetary Astrophysics · Physics 2015-06-23 Chris W. Ormel , Ji-Ming Shi , Rolf Kuiper

We perform numerical simulations of the Kelvin-Helmholtz instability in the mid-plane of a protoplanetary disk. A two-dimensional corotating slice in the azimuthal--vertical plane of the disk is considered where we include the Coriolis…

Astrophysics · Physics 2009-11-13 Anders Johansen , Thomas Henning , Hubert Klahr

The discovery that axisymmetric dust rings are ubiquitous in protoplanetary disks has provoked a flurry of research on the role of pressure bumps in planet formation. High-resolution simulations by our group have shown that even a modest…

Earth and Planetary Astrophysics · Physics 2022-03-14 Daniel Carrera , Andrew Thomas , Jacob B. Simon , Matthew A. Small , Katherine A. Kretke , Hubert Klahr

We present results of a simulation study of inelastic hard-disks vibrated in a vertical container. An Event-Driven Molecular Dynamics method is developed for studying the onset of convection. Varying the relevant parameters (inelasticity,…

Statistical Mechanics · Physics 2016-08-31 Daniela Paolotti , Alain Barrat , Umberto Marini Bettolo Marconi , Andrea Puglisi

We study the collision rates and velocities for point-particles of different sizes in turbulent flows. We construct fits for the collision rates at specified velocities (effectively a collisional velocity probability distribution) for…

Earth and Planetary Astrophysics · Physics 2015-06-15 Alexander Hubbard

Collisions between particles suspended in a fluid play an important role in many physical processes. As an example, collisions of microscopic water droplets in clouds are a necessary step in the production of macroscopic raindrops.…

Fluid Dynamics · Physics 2016-04-20 Alain Pumir , Michael Wilkinson

This white paper submitted for 2020 Decadal Assessment of Plasma Science concerns the importance of multi-spacecraft missions to address fundamental questions concerning plasma turbulence. Plasma turbulence is ubiquitous in the universe,…

Turbulence plays a key role in the transport of pebble-sized particles. It also affects the ability of pebbles to be accreted by protoplanets, because it stirs pebbles out of the disk midplane. In addition, turbulence can suppress pebble…

Earth and Planetary Astrophysics · Physics 2018-08-08 Chris W. Ormel , Beibei Liu

Accurately observing the rarefied media of the upper atmosphere, exosphere, and planetary and solar system environments and beyond requires highly sensitive metrological techniques. We present the operating concept and architecture of an…

Among the candidates for generating turbulence in accretion discs in situations with low intrinsic ionization the vertical shear instability (VSI) has become an interesting candidate, as it relies purely on a vertical gradient in the…

Earth and Planetary Astrophysics · Physics 2016-10-19 Moritz H. R. Stoll , Wilhelm Kley

The coagulation of dust particles is a key process in planetesimal formation. However, the radial drift and bouncing barriers are not completely resolved, especially for silicate dust. Since the collision velocities of dust particles are…

Earth and Planetary Astrophysics · Physics 2018-02-28 Takashi Ishihara , Naoki Kobayashi , Kei Enohata , Masayuki Umemura , Kenji Shiraishi

In this paper, the collective dynamics of the large aspect ratio dusty plasma is studied over a wide range of discharge parameters. An inductively coupled diffused plasma, which creates an electrostatic trap to confine the negatively…

Plasma Physics · Physics 2018-03-14 Mangilal Choudhary , S. Mukherjee , P. Bandyopadhyay

Small dust grains are essential ingredients of star, disk and planet formation. We present an Eulerian numerical approach to study small dust grains dynamics in the context of star and protoplanetary disk formation. It is designed for…

Instrumentation and Methods for Astrophysics · Physics 2019-06-19 Ugo Lebreuilly , Benoît Commerçon , Guillaume Laibe

Many protoplanetary disks exhibit annular gaps in dust emission, which may be produced by planets. Simulations of planet-disk interaction aimed at interpreting these observations often treat the disk thermodynamics in an overly simplified…

Earth and Planetary Astrophysics · Physics 2020-12-02 Ryan Miranda , Roman R. Rafikov

Substellar atmospheres are observed to be irregularly variable for which the formation of dust clouds is the most promising candidate explanation. The atmospheric gas is convectively unstable and, last but not least, colliding convective…

Astrophysics · Physics 2007-05-23 Christiane Helling , Rupert Klein , Erwin Sedlmayr