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Related papers: A Lower Angular Momentum Limit for Self-Gravitatin…

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We present high-resolution 3D smoothed particle hydrodynamics simulations of the formation and evolution of protostellar discs in a turbulent molecular cloud. Using a piecewise polytropic equation of state, we perform two sets of…

Earth and Planetary Astrophysics · Physics 2015-05-18 T. Hayfield , L. Mayer , J. Wadsley , A. C. Boley

We present analytic models for the local structure of self-regulated self-gravit ating accretion discs that are subject to realistic cooling. Such an approach can be used to predict the secular evolution of self-gravitating discs (which can…

Solar and Stellar Astrophysics · Physics 2015-05-13 C. Clarke

We present self-similar solutions that describe the gravitational collapse of rotating, isothermal, magnetic molecular-cloud cores, relevant to the formation of rotationally supported protostellar disks. This work focuses on the evolution…

Astrophysics · Physics 2009-11-07 Ruben Krasnopolsky , Arieh Konigl

We examine whether massive-star accretion disks are likely to fragment due to self-gravity. Rapid accretion and high angular momentum push these disks toward fragmentation, whereas viscous heating and the high protostellar luminosity…

Astrophysics · Physics 2009-11-11 Kaitlin M. Kratter , Christopher D. Matzner

We use time-dependent, one-dimensional disc models to investigate the evolution of protostellar discs that form through the collapse of molecular cloud cores and in which the primary transport mechanism is self-gravity. We assume that these…

Solar and Stellar Astrophysics · Physics 2015-05-14 W. K. M. Rice , J. H. Mayo , P. J. Armitage

Angular momentum transport within young massive protoplanetary discs may be dominated by self-gravity at radii where the disk is too weakly ionized to allow the development of the magneto-rotational instability. We use time-dependent…

Solar and Stellar Astrophysics · Physics 2011-11-15 W. K. M. Rice , P. J. Armitage

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

A number of previous studies of the fragmentation of self-gravitating protostellar discs have modeled radiative cooling with a cooling timescale (t_{cool}) parameterised as a simple multiple (beta_{cool}) of the local dynamical timescale.…

Astrophysics · Physics 2009-11-13 C. Clarke , E. Harper-Clark , G. Lodato

We investigate the fragmentation criterion in massive self-gravitating discs. We present new analysis of the fragmentation conditions which we test by carrying out global three-dimensional numerical simulations. Whilst previous work has…

Earth and Planetary Astrophysics · Physics 2015-05-19 Farzana Meru , Matthew R. Bate

The collapse and fragmentation of initially filamentary, magnetic molecular clouds is calculated in three dimensions with a gravitational, radiative hydrodynamics code. The code includes magnetic field effects in an approximate manner:…

Astrophysics · Physics 2015-06-24 Alan P. Boss

Subsequent to Paper I, the evolution and fragmentation of a rotating magnetized cloud are studied with use of three-dimensional MHD nested-grid simulations. After the isothermal runaway collapse, an adiabatic gas forms a protostellar first…

Astrophysics · Physics 2009-11-13 Masahiro N Machida , Tomoaki Matsumoto , Tomoyuki Hanawa , Kohji Tomisaka

The formation of protoplanetary discs during the collapse of molecular dense cores is significantly influenced by angular momentum transport, notably by the magnetic torque. In turn, the evolution of the magnetic field is determined by…

Astrophysics of Galaxies · Physics 2017-02-01 Patrick Hennebelle , Benoit Commercon , Gilles Chabrier , Pierre Marchand

We investigate the role of magnetic fields in the fragmentation of self-gravitating discs using 3D global ideal magnetohydrodynamic simulations performed with the "phantom" smoothed particle hydrodynamics code. For initially toroidal…

Earth and Planetary Astrophysics · Physics 2017-02-22 Duncan Forgan , Daniel J. Price , Ian Bonnell

We study numerically the collapse of rotating, magnetized molecular cloud cores, focusing on rotation and magnetic braking during the main accretion phase of isolated star formation. Motivated by previous numerical work and analytic…

Astrophysics · Physics 2009-11-10 A. Allen , Z. Y. Li , F. H. Shu

Gravitational collapse of the cylindrical elongated cloud is studied by numerical magnetohydrodynamical simulations. In the infinitely long cloud in hydrostatic configuration, small perturbations grow by the gravitational instability. The…

Astrophysics · Physics 2009-10-22 Kohji Tomisaka

We propose a framework for understanding the fragmentation criterion for self-gravitating discs which, in contrast to studies that emphasise the `gravoturbulent' nature of such discs, instead focuses on the properties of their quasi-regular…

Solar and Stellar Astrophysics · Physics 2015-06-09 Matthew D. Young , Cathie J. Clarke

The fragmentation of molecular cloud cores a factor of 1.1 denser than the critical Bonnor-Ebert sphere is examined though three-dimensional numerical simulations. A nested grid is employed to resolve fine structure down to 1 AU while…

Astrophysics · Physics 2009-11-07 Tomoaki Matsumoto , Tomoyuki Hanawa

It has already been shown, using a local model, that accretion discs with cooling times t_cool <= 3 Omega^-1 fragment into gravitationally bound objects, while those with cooling times t_cool > 3 Omega^-1 evolve into a quasi-steady state.…

Astrophysics · Physics 2007-05-23 W. K. M. Rice , P. J. Armitage , I. A. Bonnell , M. R. Bate

We investigate numerically and semi-analytically the collapse of low-mass, rotating prestellar cores. Initially, the cores are in approximate equilibrium with low rotation (the initial ratio of thermal to gravitational energy is $\alpha_0…

Astrophysics · Physics 2009-11-10 P. Hennebelle , A. Whitworth , S. Cha , S. Goodwin

Semi-analytic models of self-gravitating discs often approximate the angular momentum transport generated by the gravitational instability using the phenomenology of viscosity. This allows the employment of the standard viscous evolution…

Solar and Stellar Astrophysics · Physics 2015-05-19 Duncan Forgan , Ken Rice , Peter Cossins , Giuseppe Lodato
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