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Related papers: Hall-effect Controlled Gas Dynamics in Protoplanet…

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Parker problem in Hall magnetohydrodynamics (MHD) is considered. Poloidal shear into the toroidal flow generated by the Hall effect is incorporated. This is found to lead to a {\it triple deck} structure for the Parker problem in Hall MHD,…

Space Physics · Physics 2015-05-13 Bhimsen K. Shivamoggi

It is well known that non-ideal magnetohydrodynamic effects are important in the dynamics of molecular clouds: both ambipolar diffusion and possibly the Hall effect have been identified as significant. We present the results of a suite of…

Astrophysics of Galaxies · Physics 2014-11-20 T. P. Downes , S. O'Sullivan

Context. Current research has established magnetised disc winds as a promising way of driving accretion in protoplanetary discs. Aims. We investigate the evolution of large protoplanetary disc populations under the influence of magnetically…

Earth and Planetary Astrophysics · Physics 2023-06-21 Jesse Weder , Christoph Mordasini , Alexandre Emsenhuber

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

The degree of coupling between dust particles and their surrounding gas in protoplanetary disks is quantified by the dimensionless Stokes number. The Stokes number (St) governs particle size and spatial distributions, in turn establishing…

Earth and Planetary Astrophysics · Physics 2024-08-02 Teng Ee Yap , Konstantin Batygin

Models of planet-disk interaction are mainly based on 2D and 3D viscous hydrodynamical simulations. Accretion is classically prescribed by an alpha parameter which characterizes the turbulent radial transport of angular momentum (AM) in the…

Solar and Stellar Astrophysics · Physics 2023-05-22 Gaylor Wafflard-Fernandez , Geoffroy Lesur

The aim of this paper is to study the vertical profile of small dust particles in protoplanetary discs in which angular momentum transport is due to MHD turbulence driven by the magnetorotational instability. We consider particle sizes that…

Earth and Planetary Astrophysics · Physics 2009-11-13 Sebastien Fromang , Richard P. Nelson

The vertical structure of black hole accretion disks in which radiation dominates the total pressure is investigated using a three-dimensional radiation-MHD calculation. The domain is a small patch of disk centered 100 Schwarzschild radii…

Astrophysics · Physics 2009-11-10 N. J. Turner

Pebble accretion is one of the major theories in planet formation. Aerodynamically small particles, called pebbles, are highly affected by the gas flow. A growing planet embedded in a protoplanetary disk induces three-dimensional (3D) gas…

Earth and Planetary Astrophysics · Physics 2020-10-28 Ayumu Kuwahara , Hiroyuki Kurokawa

Global stationary configurations of both aligned and logarithmic spiral MHD perturbations are constructed analytically within an axisymmetric background ofrazor-thin scale-free gas disc, which is embedded in an axisymmetric gravitational…

Astrophysics · Physics 2009-11-11 Yue Wu , Yu-Qing Lou

Rings and gaps are routinely observed in the dust continuum emission of protoplanetary discs (PPDs). How they form and evolve remains debated. Previous studies have demonstrated the possibility of spontaneous gas rings and gaps formation in…

Earth and Planetary Astrophysics · Physics 2024-08-15 Chun-Yen Hsu , Zhi-Yun Li , Yisheng Tu , Xiao Hu , Min-Kai Lin

We studied the magnetic field structures and dynamics of magnetized multiphase gas on parsec scales around supermassive black holes by using global 3D magnetohydrodynamics (MHD) simulations. We considered the effect of radiative cooling and…

Astrophysics of Galaxies · Physics 2020-11-25 Yuki Kudoh , Keiichi Wada , Colin Norman

We present global 3D MHD simulations of disks of gas and solids, aiming at developing models that can be used to study various scenarios of planet formation and planet-disk interaction in turbulent accretion disks. A second goal is to show…

Astrophysics · Physics 2009-11-13 W. Lyra , A. Johansen , H. Klahr , N. Piskunov

We present new simulations of the evolution of axially symmetric magnetic fields in neutron star crusts under the influence of the Hall effect and subdominant Ohmic dissipation. In the Hall effect, differential rotation of the electron…

Solar and Stellar Astrophysics · Physics 2015-06-18 K. N. Gourgouliatos , A. Cumming

Building on our first paper in this series, we investigate the impact of radial magnetic fields and non-ideal magnetohydrodynamic (MHD) effects - specifically, Ohmic resistivity, Hall drift, and ambipolar diffusion - on RWI unstable modes.…

Earth and Planetary Astrophysics · Physics 2025-05-06 Can Cui , Zijin Wang

The magnetic field in Hall plasmas is frozen in the electron component and is advected not only with the plasma motion but also with the electrical current flow. Its coupling with the plasma may be not as strong as characteristic of the MHD…

Astrophysics · Physics 2009-11-06 L. I. Rudakov

Rings and gaps have been observed in a wide range of protoplanetary discs, from young systems like HLTau to older discs like TW Hydra. Recent disc simulations have shown that magnetohydrodynamic (MHD) turbulence (in the ideal or non-ideal…

Earth and Planetary Astrophysics · Physics 2019-05-29 A. Riols , G. Lesur

Hyper-accreting discs occur in compact-object mergers and collapsars, and may power gamma-ray bursts (GRBs). We calculate the microscopic viscosity and resistivity of plasma in these discs, and discuss the implications for their global…

Astrophysics · Physics 2009-11-13 Elena M. Rossi , Philip J. Armitage , Kristen Menou

Outflows play a pivotal role in star formation as one of its most visible markers and a means of transporting mass, momentum, and angular momentum from the infalling gas into the surrounding molecular cloud. Their wide reach (at least…

Solar and Stellar Astrophysics · Physics 2024-03-18 Shantanu Basu , Mahmoud Sharkawi , Masahiro N. Machida

Polarisation measurements by the Event Horizon Telescope from M87$^{\ast}$ and Sgr A$^\ast$ suggest that there is a dynamically strong, ordered magnetic field, typical of what is expected of a magnetically arrested accretion disk (MAD). In…

High Energy Astrophysical Phenomena · Physics 2024-07-29 León Salas , Gibwa Musoke , Koushik Chatterjee , Sera Markoff , Oliver Porth , Matthew Liska , Bart Ripperda