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We study the formation of the protoplanetary disk by the collapse of a primordial molecular cloud, and how its evolution leads to the selection of specific types of planets. We use a hydrodynamical code that accounts for the dynamics,…

Earth and Planetary Astrophysics · Physics 2019-04-17 Kevin Baillié , Joao Marques , Laurent Piau

(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…

We analyze the gravitational collapse of solids subject to gas drag in a protoplanetary disk. We also study the stirring of solids by turbulent fluctuations to determine the velocity dispersion and thickness of the midplane particle layer.…

Astrophysics · Physics 2007-05-23 Andrew N. Youdin

Study of pre-stellar cloud evolution requires observations with high sensitivity and resolution, and regions of high-mass star formation are particularly challenging. We wish to quantify, to what accuracy the physical conditions within a…

Astrophysics of Galaxies · Physics 2022-10-12 M. Juvela , E. Mannfors , T. Liu , L. V. Toth

The conditions in the protoplanetary disc are determinant for the various planet formation mechanisms. We present a framework which combines self-consistent disc structures with the calculations of the growth rates of planetary embryos via…

Earth and Planetary Astrophysics · Physics 2021-06-23 Sofia Savvidou , Bertram Bitsch

Using self-consistent models of turbulent particle growth in an evolving protoplanetary nebula of solar composition we find that recently proposed local metallicity and Stokes number criteria necessary for the streaming instability to…

Earth and Planetary Astrophysics · Physics 2023-03-29 Paul R. Estrada , Orkan M. Umurhan

Stars form in cold clouds of predominantly molecular (H2) gas. We are just beginning to understand how the formation, properties, and destruction of these clouds varies across the universe. In this chapter, we describe how the thermal line…

Astrophysics of Galaxies · Physics 2018-10-17 Adam K. Leroy , Alberto Bolatto , Erik Rosolowsky , Eva Schinnerer

Kant and Laplace suggested the Solar System formed from a rotating gaseous disk in the 18th century, but convincing evidence that young stars are indeed surrounded by such disks was not presented for another 200 years. As we move into the…

Astrophysics · Physics 2008-01-25 Claire J. Chandler , Debra S. Shepherd

We model the evolution of protoplanetary disks surrounding millisecond pulsars, using PSR 1257+12 as a test case. Initial conditions were chosen to correspond to initial angular momenta expected for supernova-fallback disks and disks formed…

Astrophysics · Physics 2019-08-19 Thayne Currie , Brad Hansen

We present a model in which planetesimal disks are built from the combination of planetesimal formation and accretion of radially drifting pebbles onto existing planetesimals. In this model, the rate of accretion of pebbles onto…

Earth and Planetary Astrophysics · Physics 2015-08-19 John Moriarty , Debra Fischer

Planet formation encompasses processes that span a remarkable 40 magnitudes in mass, ranging from collisions between micron-sized grains inherited from the ISM to the accretion of gas by giant planets. The planet formation process takes…

Earth and Planetary Astrophysics · Physics 2024-12-18 Chris Ormel

We outline a scenario which traces a direct path from freely-floating nebula particles to the first 10-100km-sized bodies in the terrestrial planet region, producing planetesimals which have properties matching those of primitive meteorite…

Astrophysics · Physics 2009-06-23 Jeffrey N. Cuzzi , Robert C. Hogan , Karim Shariff

Terrestrial planets form in a series of dynamical steps from the solid component of circumstellar disks. First, km-sized planetesimals form likely via a combination of sticky collisions, turbulent concentration of solids, and gravitational…

Astrophysics · Physics 2009-11-13 Sean N. Raymond

It is widely held that the first step in forming the gas giant planets, such as Jupiter and Saturn, is to form solid `cores' of roughly 10 M$_\oplus$. Getting the cores to form before the solar nebula dissipates ($\sim\!1-10\,$Myr) has been…

Earth and Planetary Astrophysics · Physics 2015-10-09 Harold F. Levison , Katherine A. Kretke , Martin J. Duncan

We hypothesise that planets are made by tidal downsizing of migrating giant planet embryos. The proposed scheme for planet formation consists of these steps: (i) a massive young protoplanetary disc fragments at R ~ several tens to hundreds…

Earth and Planetary Astrophysics · Physics 2015-05-19 Sergei Nayakshin

The ring-like structures in protoplanetary discs that are observed in the cold dust emission by ALMA, might be explained by dust aggregates trapped aerodynamically in pressure maxima. The effect of a transient pressure maximum is…

Earth and Planetary Astrophysics · Physics 2024-06-05 Zs. Sándor , O. M. Guilera , Zs. Regály , W. Lyra

The formation mechanism of planetesimals in protoplanetary discs is hotly debated. Currently, the favoured model involves the accumulation of meter-sized objects within a turbulent disc, followed by a phase of gravitational instability. At…

Earth and Planetary Astrophysics · Physics 2010-03-16 Hanno Rein , Geoffroy Lesur , Zoe M. Leinhardt

Recent advances in our understanding of massive star formation have made clear the important role of protostellar disks in mediating accretion. Here we describe a simple, semi-analytic model for young, deeply embedded, massive accretion…

Astrophysics · Physics 2007-12-07 Kaitlin M. Kratter , Christopher D. Matzner , Mark. R. Krumholz

We perform a comparative numerical hydrodynamics study of embedded protostellar disks formed as a result of the gravitational collapse of cloud cores of distinct mass (M_cl=0.2--1.7 M_sun) and ratio of rotational to gravitational energy…

Solar and Stellar Astrophysics · Physics 2015-05-19 Eduard I. Vorobyov

Protoplanetary disks (PPDs) surrounding young stars are short-lived (~0.3-10 Myr), compact (~10-1000 AU) rotating reservoirs of gas and dust. PPDs are believed to be birthplaces of planetary systems, where tiny grains are assembled into…

Astrophysics of Galaxies · Physics 2010-11-23 Dmitry Semenov
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