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Related papers: Hall Effect in Protostellar Disc Formation and Evo…

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We present a numerical model for the evolution of a protostellar disc that has formed self-consistently from the collapse of a molecular cloud core. The global evolution of the disc is followed for several million years after its formation.…

Astrophysics · Physics 2009-11-13 E. I. Vorobyov , S. Basu

Given the important role turbulence plays in the settling and growth of dust grains in protoplanetary disks, it is crucial that we determine whether these disks are turbulent and to what extent. Protoplanetary disks are weakly ionized near…

Earth and Planetary Astrophysics · Physics 2024-04-12 David G. Rea , Jacob B. Simon , Daniel Carrera , Geoffroy Lesur , Wladimir Lyra , Debanjan Sengupta , Chao-Chin Yang , Andrew N. Youdin

We perform axisymmetric resistive MHD calculations that demonstrate that centrifugal disks can indeed form around Class 0 objects despite magnetic braking. We follow the evolution of a prestellar core all the way to near-stellar densities…

Solar and Stellar Astrophysics · Physics 2013-08-19 Wolf B. Dapp , Shantanu Basu

Turbulent motion driven by the magnetorotational instability (MRI) is believed to provide an anomalous viscosity strong enough to account for observed accretion rates in protostellar accretion disks. In the first of two papers, we perform…

Solar and Stellar Astrophysics · Physics 2015-06-19 Wayne O'Keeffe , Turlough P. Downes

We present a 3-D ideal MHD simulation of magnetospheric accretion onto a non-rotating star. The accretion process unfolds with intricate 3-D structures driven by various mechanisms. First, the disc develops filaments at the magnetospheric…

Solar and Stellar Astrophysics · Physics 2023-12-18 Zhaohuan Zhu , James M. Stone , Nuria Calvet

Starting from a prestellar core with a size of $1.2\times10^4$ AU, we calculate the evolution of a gravitationally collapsing core until $\sim2000$ yr after protostar formation using a three-dimensional resistive magnetohydrodynamic…

Solar and Stellar Astrophysics · Physics 2019-05-29 Masahiro N. Machida , Shantanu Basu

The effect of the Hall term on the evolution of the magnetorotational instability (MRI) in weakly ionized accretion disks is investigated using local axisymmetric simulations. First, we show that the Hall term has important effects on the…

Astrophysics · Physics 2009-11-07 Takayoshi Sano , James M. Stone

We present here a minor modification of our numerical implementation of the Hall effect for the 2D Riemann solver used in Constrained Transport schemes, as described in Marchand et al. (2018). In the previous work, the tests showed that the…

Solar and Stellar Astrophysics · Physics 2019-10-29 Pierre Marchand , Kengo Tomida , Benoît Commerçon , Gilles Chabrier

We investigate the formation and fragmentation of discs using a suite of three-dimensional smoothed particle radiative magnetohydrodynamics simulations. Our models are initialised as 1M$_\odot$ rotating Bonnor-Ebert spheres that are…

Solar and Stellar Astrophysics · Physics 2019-04-17 James Wurster , Matthew R. Bate

We consider formation of accretion disks from a realistically turbulent molecular gas using 3D MHD simulations. In particular, we analyze the effect of the fast turbulent reconnection described by the Lazarian & Vishniac (1999) model for…

Solar and Stellar Astrophysics · Physics 2016-03-16 Diego F. González-Casanova , Reinaldo Santos-Lima , Alexander Lazarian

The problem of the late accretion phase of the evolution of an axisymmetric, isothermal magnetic disk surrounding a forming star has been formulated in a companion paper. The "central sink approximation" is used to circumvent the problem of…

Astrophysics · Physics 2009-11-10 Konstantinos Tassis , Telemachos Ch. Mouschovias

Using resistive magnetohydrodynamics simulation, we investigate circumstellar disk formation in a strongly magnetized cloud. As the initial state, an isolated cloud core embedded in a low-density interstellar medium with a uniform magnetic…

Solar and Stellar Astrophysics · Physics 2015-05-19 Masahiro N. Machida , Shu-ichiro Inutsuka , Tomoaki Matsumoto

Stars form in dense cores of molecular clouds that are observed to be significantly magnetized. In the simplest case of a laminar (non-turbulent) core with the magnetic field aligned with the rotation axis, both analytic considerations and…

Solar and Stellar Astrophysics · Physics 2015-06-12 Zhi-Yun Li , Ruben Krasnopolsky , Hsien Shang

Are the kG-strength magnetic fields observed in young stars a fossil field left over from their formation or are they generated by a dynamo? Our previous numerical study concluded that magnetic fields must originate by a dynamo process.…

Solar and Stellar Astrophysics · Physics 2022-01-20 James Wurster , Matthew R. Bate , Daniel J. Price , Ian A. Bonnell

Weakly ionized protoplanetary disks (PPDs) are subject to non-ideal-magnetohydrodynamic (MHD) effects including Ohmic resistivity, the Hall effect and ambipolar diffusion (AD), and the resulting magnetic diffusivities ($\eta_O, \eta_H$ and…

Earth and Planetary Astrophysics · Physics 2016-03-16 Rui Xu , Xue-Ning Bai

We have carried out and analyzed a set of axisymmetric MHD simulations of the evolution of a turbulent/diffusive accretion disc around an initially unmagnetized star. The disc is initially threaded by a weak magnetic field where the…

High Energy Astrophysical Phenomena · Physics 2015-06-12 S. Dyda , R. V. E. Lovelace , G. V. Ustyugova , P. S. Lii , M. M. Romanova , A. V. Koldoba

How embedded, actively accreting low-mass protostars accrete their mass is still greatly debated. Observations are now piecing together the puzzle of embedded protostellar accretion, in particular with new facilities in the near-infrared.…

Solar and Stellar Astrophysics · Physics 2024-12-25 Brandt A. L. Gaches , Jonathan C. Tan , Anna L. Rosen , Rolf Kuiper

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…

We study mass accretion and ejection in the vicinity of massive star forming cores using high-resolution (5 au) 3D AMR numerical simulations. We investigate the mechanisms at the origin of outflows and characterise the properties of the…

Solar and Stellar Astrophysics · Physics 2022-02-02 Benoît Commerçon , Matthias González , Raphaël Mignon-Risse , Patrick Hennebelle , Neil Vaytet

Protostellar disks around young protostars exhibit diverse properties, with their radii ranging from less than ten to several hundred au. To investigate the mechanisms shaping this disk radius distribution, we compiled a sample of 27 Class…

Solar and Stellar Astrophysics · Physics 2024-08-23 Hsi-Wei Yen , Yueh-Ning Lee
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