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Related papers: On the Grain-Modified Magnetic Diffusivities in Pr…

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In protoplanetary disks around young stars, magnetic fields play an important role for disk evolution and planet formation. Polarized thermal emission from magnetically aligned grains is one of the reliable methods to trace magnetic fields.…

Earth and Planetary Astrophysics · Physics 2025-02-11 Satoshi Ohashi , Takayuki Muto , Yusuke Tsukamoto , Akimasa Kataoka , Takashi Tsukagoshi , Munetake Momose , Misato Fukagawa , Nami Sakai

Thermal dust polarization is a powerful tool to probe magnetic fields ($\textbf{B}$) and grain properties. However, a systematic study of the dependence of dust polarization on grain properties in protostellar environments is not yet…

Astrophysics of Galaxies · Physics 2024-03-14 Nguyen Chau Giang , Thiem Hoang

The planet-forming region of protoplanetary disks is cold, dense, and therefore weakly ionized. For this reason, magnetohydrodynamic (MHD) turbulence is thought to be mostly absent, and another mechanism has to be found to explain gas…

Earth and Planetary Astrophysics · Physics 2017-04-05 William Béthune , Geoffroy Lesur , Jonathan Ferreira

It has been shown that a realistic level of magnetization of dense molecular cloud cores can suppress the formation of a rotationally supported disk (RSD) through catastrophic magnetic braking in the axisymmetric ideal MHD limit. In this…

Solar and Stellar Astrophysics · Physics 2016-06-15 Bo Zhao , Paola Caselli , Zhi-Yun Li , Ruben Krasnopolsky , Hsien Shang , Fumitaka Nakamura

This paper studies the response of a thin accretion disk to an external radial magnetic field. Our focus is on protoplanetary disks (PPDs), which are exposed during their later evolution to an intense, magnetized wind from the central star.…

Earth and Planetary Astrophysics · Physics 2015-11-04 Matthew Russo , Christopher Thompson

The magnetohydrodynamical behavior (MHD) of accretion disks is reviewed. A detailed presentation of the fundamental MHD equations appropriate for protostellar disks is given. The combination of a weak (subthermal) magnetic field and…

Solar and Stellar Astrophysics · Physics 2009-06-05 Steven A. Balbus

We investigate the dynamics of the accretion disks of young stars with fossil large-scale magnetic field. The author's magnetohydrodynamic (MHD) model of the accretion disks is generalized to consider the dynamical influence of the magnetic…

Solar and Stellar Astrophysics · Physics 2022-12-28 Sergey A. Khaibrakhmanov , Alexander E. Dudorov

The destabilising effect of Hall diffusion in a Keplerian disc allows the MRI to occur for much lower ionisation levels than would otherwise be possible. However, simulations suggest that the consequences for the saturated state are not as…

Earth and Planetary Astrophysics · Physics 2015-05-27 Mark Wardle , Raquel Salmeron

We characterize magnetically driven accretion at radii between 1 au and 100 au in protoplanetary discs, using a series of local non-ideal magnetohydrodynamic (MHD) simulations. The simulations assume a Minimum Mass Solar Nebula (MMSN) disc…

Solar and Stellar Astrophysics · Physics 2015-10-07 Jacob B. Simon , Geoffroy Lesur , Matthew W. Kunz , Philip J. Armitage

Protoplanetary discs are poorly ionised due to their low temperatures and high column densities, and are therefore subject to three "non-ideal" magnetohydrodynamic effects: Ohmic dissipation, ambipolar diffusion, and the Hall effect. The…

Solar and Stellar Astrophysics · Physics 2014-07-02 Geoffroy Lesur , Matthew W. Kunz , Sebastien Fromang

The transport of angular momentum by magnetic fields is a crucial physical process in formation and evolution of stars and disks. Because the ionization degree in star forming clouds is extremely low, non-ideal magnetohydrodynamic (MHD)…

Solar and Stellar Astrophysics · Physics 2015-06-23 Kengo Tomida , Satoshi Okuzumi , Masahiro N. Machida

The structure of magnetic fields within protostellar disks may be studied via polarimetry provided that grains are aligned in respect to magnetic field within the disks. We explore alignment of dust grains by radiative torque in T Tauri…

Astrophysics · Physics 2009-11-11 Jungyeon Cho , A. Lazarian

Giant protoplanets evacuate a gap in their host protoplanetary disc, which gas must cross before it can be accreted. A magnetic field is likely carried into the gap, potentially influencing the flow. Gap crossing has been simulated with…

Earth and Planetary Astrophysics · Physics 2015-08-06 Sarah L. Keith , Mark Wardle

Understanding the complex evolution of protoplanetary disks (PPDs) and their dispersal via energetic stellar radiation are prominent challenges in astrophysics. It has recently been established that specifically the X-ray luminosity from…

Earth and Planetary Astrophysics · Physics 2023-10-04 Eleftheria Sarafidou , Oliver Gressel , Giovanni Picogna , Barbara Ercolano

We investigate and discuss protostellar discs in terms of where the various non-ideal magnetohydrodynamics (MHD) processes are important. We find that the traditional picture of a magnetised disc (where Ohmic resistivity is dominant near…

Solar and Stellar Astrophysics · Physics 2021-01-13 James Wurster

Using magnetohydrodynamic (MHD) adaptive mesh refinement simulations, we study the formation and early evolution of disk galaxies with a magnetized interstellar medium. For a $10^{10}$ \msun halo with initial NFW dark matter and gas…

Astrophysics · Physics 2009-04-17 Peng Wang , Tom Abel

Stars form in dense cores of molecular clouds that are observed to be significantly magnetized. A dynamically important magnetic field presents a significant obstacle to the formation of protostellar disks. Recent studies have shown that…

Solar and Stellar Astrophysics · Physics 2015-05-27 Ruben Krasnopolsky , Zhi-Yun Li , Hsien Shang

MHD turbulence plays a crucial role in the dust dynamics of protoplanetary discs. It affects planet formation, vertical settling and is one possible origin of the large scale axisymmetric structures, such as rings, recently imaged by ALMA…

Earth and Planetary Astrophysics · Physics 2018-10-03 A. Riols , G. Lesur

The gas temperature in protoplanetary disks (PPDs) is determined by a combination of irradiation heating and accretion heating, with the latter conventionally attributed to turbulent dissipation. However, recent studies have suggested that…

Earth and Planetary Astrophysics · Physics 2019-03-01 Shoji Mori , Xue-Ning Bai , Satoshi Okuzumi

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