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Related papers: Numerical study of self-gravitating protoplanetary…

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We obtain a new set of analytical solutions for the evolution of a self-gravitating accretion disc by holding the Toomre parameter close to its threshold, and obtaining the stress parameter from the cooling rate. In agreement with the…

Earth and Planetary Astrophysics · Physics 2017-05-02 Fazeleh Khajenabi , Kimia Kazrani , Mohsen Shadmehri

We obtain self-similar solutions that describe the dynamics of a self-gravitating, rotating, viscous system. We use simplifying assumptions; but explicitly include viscosity and the cooling due to the dissipation of energy. By assuming that…

Astrophysics · Physics 2009-11-07 Mohsen Shadmehri , Jamshid Ghanbari

Using radiation magnetohydrodynamics simulations with realistic opacities and equation of state, and zero net magnetic flux, we have explored thermodynamics in the inner part of protoplanetary discs where magnetic turbulence is expected.…

High Energy Astrophysical Phenomena · Physics 2015-06-23 Shigenobu Hirose

Self-similar and semi-analytical solutions are found for the height-averaged equations govern the dynamical behavior of a polytropic, self-gravitating disk under the effects of winds, around the nascent object. In order to describe time…

Solar and Stellar Astrophysics · Physics 2015-06-11 Shahram Abbassi , Erfan Nourbakhsh , Mohsen Shadmehri

Observations indicate that stars generally lose their protoplanetary discs on a timescale of about 5 Myr. Which mechanisms are responsible for the disc dissipation is still debated. Here we investigate the movement through an ambient medium…

Solar and Stellar Astrophysics · Physics 2017-06-21 T. P. G. Wijnen , O. R. Pols , F. I. Pelupessy , S. Portegies Zwart

The formation of a circumplanetary disk and accretion of angular momentum onto a protoplanetary system are investigated using 3D hydrodynamical simulations. The local region around a protoplanet in a protoplanetary disk is considered with…

Astrophysics · Physics 2008-10-16 Masahiro N. Machida

Accretion discs are ubiquitous in the universe and it is a crucial issue to understand how angular momentum and mass are being radially transported in these objects. Here, we study the role played by non-linear spiral patterns within…

Astrophysics of Galaxies · Physics 2016-05-04 Patrick Hennebelle , Geoffroy Lesur , Sébastien Fromang

Protoplanetary disks fragment due to gravitational instability when there is enough mass for self-gravitation, described by the Toomre parameter, and when heat can be lost at a rate comparable to the local dynamical timescale, described by…

Earth and Planetary Astrophysics · Physics 2015-12-08 Hans Baehr , Hubert Klahr

Cold optically thick accretion disks with hot coronae and radial advection have been investigated. Within the framework of $\alpha$-viscosity models, we assume that all the mass accretion and angular momentum transport take place in the…

Astrophysics · Physics 2009-10-28 Xingming Chen

We present a model for the transport of anisotropic turbulence in an accretion disc. The model uses the Reynolds stress tensor approach in the mean field approximation. To study the role of convection in a protoplanetary disc, we combine…

Solar and Stellar Astrophysics · Physics 2023-11-06 E. P. Kurbatov , Ya. N. Pavlyuchenkov

In this paper, we extend our previous analysis (Lodato & Rice 2004) of the transport properties induced by gravitational instabilities in cooling, gaseous accretion discs to the case where the disc mass is comparable to the central object.…

Astrophysics · Physics 2009-11-10 G. Lodato , W. K. M. Rice

The vertical temperature structure of a protoplanetary disk bears on several processes relevant to planet formation, such as gas and dust grain chemistry, ice lines and convection. The temperature profile is controlled by irradiation from…

Earth and Planetary Astrophysics · Physics 2020-05-07 William Béthune , Henrik Latter

The nature and rate of (viscous) angular momentum transport in protoplanetary discs (PPDs) has important consequences for the formation process of planetary systems. While accretion rates onto the central star yield constraints on such…

Earth and Planetary Astrophysics · Physics 2020-06-11 Andrew J. Winter , Megan Ansdell , Thomas J. Haworth , J. M. Diederik Kruijssen

We consider the accretion process in a disk with magnetic fields that are dragged in from the interstellar medium by gravitational collapse. Two diffusive processes are at work in the system: (1) "viscous" torques exerted by turbulent and…

Protoplanetary disks are believed to evolve on Myr timescales in a diffusive (viscous) manner as a result of angular momentum transport driven by internal stresses. Here we use a sample of 26 protoplanetary disks resolved by ALMA with…

Earth and Planetary Astrophysics · Physics 2017-03-22 Roman R. Rafikov

Young protostellar discs are likely to be both self-gravitating, and to support grain growth to sizes where the particles decoupled from the gas. This combination could lead to short-wavelength fragmentation of the solid component in…

Earth and Planetary Astrophysics · Physics 2023-05-17 Cristiano Longarini , Philip J. Armitage , Giuseppe Lodato , Daniel J. Price , Simone Ceppi

We explore the properties of cold gravitoturbulent accretion disks - non-fragmenting disks hovering on the verge of gravitational instability - using a realistic prescription for the effective viscosity caused by gravitational torques. This…

Earth and Planetary Astrophysics · Physics 2009-10-02 Roman R. Rafikov

The issue of fragmentation in self-gravitating gaseous accretion discs has implications both for the formation of stars in discs in the nuclei of active galaxies, and for the formation of gaseous planets or brown dwarfs in circumstellar…

Astrophysics · Physics 2009-11-13 W. K. M. Rice , G. Lodato , P. J. Armitage

The existence of outflow in accretion flows is confirmed by observations and magnetohydrodynamics (MHD) simulations. In this paper, we study outflows of accretion flows in the presence of resistivity and toroidal magnetic field. The…

High Energy Astrophysical Phenomena · Physics 2012-05-11 Kazem Faghei , Azam Mollatayefeh

The thermal structure of a protoplanetary disc is regulated by the opacity that dust grains provide. However, previous works have often considered simplified prescriptions for the dust opacity in hydrodynamical disc simulations, e.g. by…

Earth and Planetary Astrophysics · Physics 2020-08-19 Sofia Savvidou , Bertram Bitsch , Michiel Lambrechts