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Related papers: Instabilities and Flow Structures in Protoplanetar…

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Rotating, turbulent cosmic fluids are generally pervaded by coherent structures such as vortices and magnetic flux tubes. The formation of such structures is a robust property of rotating turbulence as has been confirmed in computer…

Astrophysics · Physics 2007-05-23 A. Bracco , A. Provenzale , E. A. Spiegel , P. Yecko

We explore the effect of magnetorotational turbulence on the dynamics and concentrations of boulders in local box simulations of a sub-Keplerian protoplanetary disc. The solids are treated as particles each with an independent space…

Astrophysics · Physics 2007-05-23 Anders Johansen , Hubert Klahr , Thomas Henning

(abridged) Angular momentum transport and accretion in protoplanetary discs are generally believed to be driven by MHD turbulence via the magneto-rotational instability (MRI). The dynamics of solid bodies embedded in such discs (dust…

Earth and Planetary Astrophysics · Physics 2015-05-19 Richard P. Nelson , Oliver Gressel

A critical step toward the emergence of planets in a protoplanetary disk consists in accretion of planetesimals, bodies 1-1000 km in size, from smaller disk constituents. This process is poorly understood partly because we lack good…

Earth and Planetary Astrophysics · Physics 2019-06-28 David Nesvorny , Rixin Li , Andrew N. Youdin , Jacob B. Simon , William M. Grundy

We show that small solids in low mass, turbulent protoplanetary disks collect into self-gravitating rings. Growth is faster than disk lifetimes and radial drift times for moderately strong turbulence, characterized by dimensionless…

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

The building of planetary systems is controlled by the gas and dust dynamics of protoplanetary disks. While the gas is simultaneously accreted onto the central star and dissipated away by winds, dust grains aggregate and collapse to form…

Recently it is proposed that porous icy dust aggregates are formed by pairwise accretion of dust aggregates beyond the snowline. We calculate the equilibrium random velocity of porous dust aggregates taking into account mutual gravitational…

Earth and Planetary Astrophysics · Physics 2016-07-20 Shugo Michikoshi , Eiichiro Kokubo

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…

Astrophysics · Physics 2009-11-13 Alexander Hubbard , Eric G. Blackman

We explore here the idea, reminiscent in some respect of Von Weizsacker's (1944) and Alfven's (1976) outmoded cosmogonies, that long-lived vortices in a turbulent protoplanetary nebula can capture large amount of solid particles and…

Astrophysics · Physics 2007-05-23 P. Barge , J. Sommeria

Planetesimal formation is a crucial yet poorly understood process in planet formation. It is widely believed that planetesimal formation is the outcome of dust clumping by the streaming instability (SI). However, recent analytical and…

Earth and Planetary Astrophysics · Physics 2022-01-12 Ziyan Xu , Xue-Ning Bai

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…

Earth and Planetary Astrophysics · Physics 2026-03-11 Sebastian Lorek , Michiel Lambrechts

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…

Earth and Planetary Astrophysics · Physics 2018-08-08 Hiroshi Kobayashi , Hidekazu Tanaka

Dust concentration in protoplanetary disks (PPDs) is the first step towards planetesimal formation, a crucial yet highly uncertain stage in planet formation. Although the streaming instability (SI) is widely recognized as a powerful…

Earth and Planetary Astrophysics · Physics 2025-04-23 Pinghui Huang , Xue-Ning Bai

In the incremental growth model, planetesimal formation constitutes the least understood step in the process of planetary formation. The two main difficulties in this regard are the collision/fragmentation and the drift barriers. Numerous…

Earth and Planetary Astrophysics · Physics 2025-08-28 H. Meheut , F. A. Gerosa , J. Bec

The formation of gas-giant planets within the lifetime of a protoplanetary disk is challenging especially far from a star. A promising model for the rapid formation of giant-planet cores is pebble accretion in which gas drag during…

Earth and Planetary Astrophysics · Physics 2021-06-30 John Chambers

The observed rapid onset of star formation in molecular clouds requires rapid formation of dense fragments which can collapse individually before being overtaken by global gravitationally-driven flows. Many previous investigations have…

Astrophysics · Physics 2009-11-13 F. Heitsch , L. Hartmann , A. Burkert , ;

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…

Earth and Planetary Astrophysics · Physics 2020-07-08 Noemi Schaffer , Anders Johansen , Lukas Cedenblad , Bernhard Mehling , Dhrubaditya Mitra

Streaming instability is a key mechanism in planet formation, clustering pebbles into planetesimals. It is triggered at a particular disk location where the local volume density of solids exceeds that of the gas. After their formation,…

Earth and Planetary Astrophysics · Physics 2019-04-24 Beibei Liu , Chris W. Ormel , Anders Johansen

The solid content of circumstellar disks is inherited from the interstellar medium: dust particles of at most a micrometer in size. Protoplanetary disks are the environment where these dust grains need to grow at least 13 orders of…

Solar and Stellar Astrophysics · Physics 2016-05-19 T. Birnstiel , M. Fang , A. Johansen

We discuss the physics of vortices in the circumstellar disks associated with young stellar objects. We elucidate the basic physical properties of these localized storm systems. In particular, we consider point vortices, linear vortices,…

Astrophysics · Physics 2016-08-30 Fred Adams , Richard Watkins
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