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Related papers: Protostellar disk accretion in turbulent filaments

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Aspects of turbulence in protostellar accretion discs are being reviewed. The emergence of dead zones due to poor ionization and alternatives to the magneto-rotational instability are discussed. The coupling between dust and gas in…

Astrophysics · Physics 2008-08-08 Axel Brandenburg

Understanding the collapse of clouds and the formation of protoplanetary disks is essential to understanding the formation of stars and planets. Infall and accretion, the mass-aggregation processes that occur at envelope and disk scales,…

Star formation proceeds via the collapse of a molecular cloud core over multiple dynamical timescales. Turbulence within cores results in a spatially non-uniform angular momentum of the cloud, causing a stochastic variation in orientation…

Earth and Planetary Astrophysics · Physics 2015-06-23 Christopher Spalding , Konstantin Batygin , Fred C. Adams

The giant, star forming clumps in gas-rich, high redshift disks are commonly assumed to form due to gravitational instabilities, in which protoclumps have a Toomre-$Q$ parameter less than unity. However, some cosmological simulations show…

Accretion onto protostars may occur in sharp bursts. Accretion bursts during the embedded phase of young protostars are probably most intense, but can only be inferred indirectly through long-wavelength observations. We perform radiative…

We investigate how the external medium surrounding prestellar cores affects the star formation process by conducting three-dimensional resistive magnetohydrodynamic simulations. The initial cores follow critical Bonnor-Ebert profiles and…

Astrophysics of Galaxies · Physics 2025-10-29 Shingo Nozaki , Masahiro N. Machida

Supercritical gas filaments in molecular clouds host the dense cores in which new stars form. The mechanisms governing their formation and subsequent gas accretion remain poorly understood. In this study, we conduct a statistical analysis…

Models of the formation, evolution and photoevaporation of circumstellar disks are an essential ingredient in many theories of the formation of planetary systems. The ratio of disk mass over stellar mass in the circumstellar phase of a disk…

Solar and Stellar Astrophysics · Physics 2015-05-18 R. Visser , C. P. Dullemond

We study protoplanetary disc evolution assuming that angular momentum transport is driven by gravitational instability at large radii, and magnetohydrodynamic (MHD) turbulence in the hot inner regions. At radii of the order of 1 AU such…

Astrophysics · Physics 2009-11-06 Philip J. Armitage , Mario Livio , J. E. Pringle

In the classical core-accretion planet formation scenario, rapid inward migration and accretion timescales of kilometer size planetesimals may not favor the formation of massive cores of giant planets before the dissipation of…

Earth and Planetary Astrophysics · Physics 2017-07-26 O. M. Guilera , Zs. Sándor

Rings and gaps are being observed in an increasing number of disks around young stellar objects. We illustrate the formation of such radial structures through idealized, 2D (axisymmetric) resistive MHD simulations of coupled disk-wind…

Solar and Stellar Astrophysics · Physics 2017-03-31 Scott S. Suriano , Zhi-Yun Li , Ruben Krasnopolsky , Hsien Shang

This paper reviews current theoretical work on the various stages of accretion in protostars, and the relationship of these ideal stages to the spectral classes of observed protostellar systems. I discuss scaling relationships that have…

Astrophysics · Physics 2009-10-30 Eve C. Ostriker

We present high-resolution zoom-in simulations of molecular clouds exposed to an interstellar radiation field and cosmic ray ionisation rate up to 1000 times stronger than that of the solar neighbourhood. We detail the evolution of the…

Transitional protostellar disks have inner cavities heavily depleted in dust and gas, yet most show signs of ongoing accretion, often at rates comparable to full disks. We show that recent constraints on the gas surface density in a few…

Earth and Planetary Astrophysics · Physics 2017-01-25 Lile Wang , Jeremy J. Goodman

Vortices in protoplanetary disks can capture solid particles and form planetary cores within shorter timescales than those involved in the standard core-accretion model. We investigate vortex generation in thin unmagnetized protoplanetary…

Astrophysics · Physics 2009-11-13 M. de Val-Borro , P. Artymowicz , G. D'Angelo , A. Peplinski

We simulate the formation and collapse of prestellar cores at few-AU resolution in a set of radiation-magneto-hydrodynamic simulations of giant molecular clouds (GMCs) using the grid-based code RAMSES-RT. We adopt, for the first time to our…

Astrophysics of Galaxies · Physics 2023-05-10 Chong-Chong He , Massimo Ricotti

We present a detailed study of the collapse of molecular cloud cores using high resolution 3D adaptive mesh refinement (AMR) numerical simulations. In this first in a series of investigations our initial conditions consists of spherical…

Astrophysics · Physics 2009-11-10 Robi Banerjee , Ralph E. Pudritz , Lindsay Holmes

We examine the idea that diffuse and giant molecular clouds and their substructure form as density fluctuations induced by large scale interstellar turbulence. We do this by investigating the topology of various fields in realistic…

Astrophysics · Physics 2009-10-30 Javier Ballesteros-Paredes , Enrique Vazquez-Semadeni , John Scalo

The streaming instability is a leading candidate mechanism to explain the formation of planetesimals. Yet, the role of this instability in the driving of turbulence in protoplanetary disks, given its fundamental nature as a linear…

Earth and Planetary Astrophysics · Physics 2020-04-08 Urs Schäfer , Anders Johansen , Robi Banerjee
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