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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)…

太阳与恒星天体物理 · 物理学 2015-06-23 Kengo Tomida , Satoshi Okuzumi , Masahiro N. Machida

It has recently been established that the evolution of protoplanetary disks is primarily driven by magnetized disk winds, requiring large-scale magnetic flux threading the disks. The size of such disks is expected to shrink in time, as…

太阳与恒星天体物理 · 物理学 2021-12-08 Haifeng Yang , Xue-Ning Bai

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…

地球与行星天体物理 · 物理学 2015-05-27 Mark Wardle , Raquel Salmeron

Non-ideal MHD effects have been shown recently as a robust mechanism of averting the magnetic braking "catastrophe" and promoting protostellar disc formation. However, the magnetic diffusivities that determine the efficiency of non-ideal…

太阳与恒星天体物理 · 物理学 2021-05-12 Bo Zhao , Paola Caselli , Zhi-Yun Li , Ruben Krasnopolsky , Hsien Shang , Ka Ho Lam

Protoplanetary discs are thought to evolve either through angular momentum transport driven by viscous processes or through angular momentum removal induced by magnetohydrodynamic (MHD) winds. One proposed method to distinguish between…

地球与行星天体物理 · 物理学 2026-02-20 Giulia Ballabio , James E. Owen

Context. Transition disks (TDs) are a type of protoplanetary disk characterized by a central dust and gas cavity. The processes behind how these cavities are formed and maintained, along with their observed high accretion rates of $10^{-8}…

地球与行星天体物理 · 物理学 2025-03-05 Eleftheria Sarafidou , Oliver Gressel , Barbara Ercolano

Imaging of the dust continuum emitted from disks around nearby protostars reveals diverse substructure. In recent years, theoretical efforts have been intensified to investigate how far the intrinsic dynamics of protoplanetary disks (PPDs)…

地球与行星天体物理 · 物理学 2019-05-31 Leonardo Krapp , Oliver Gressel , Pablo Benítez-Llambay , Turlough P. Downes , Gopakumar Mohandas , Martin E. Pessah

We estimate the mass loss rates of photoevaporative winds launched from the outer edge of protoplanetary discs impinged by an ambient radiation field. We focus on mild/moderate environments (the number of stars in the group/cluster is N ~…

太阳与恒星天体物理 · 物理学 2016-02-03 Stefano Facchini , Cathie J. Clarke , Thomas G. Bisbas

We present new analytical solutions for the evolution of protoplanetary discs (PPDs) where magnetohydrodynamic (MHD) wind-driven processes dominate. Our study uses a 1D model which incorporates equations detailing angular momentum…

星系天体物理 · 物理学 2024-01-19 Mohsen Shadmehri , Fazeleh Khajenabi

The driving mechanism of massive outflows observed in high-mass star-forming regions is investigated using three-dimensional magnetohydrodynamics (MHD) and protostellar evolution calculations. In our previous paper, we showed that the mass…

太阳与恒星天体物理 · 物理学 2018-01-31 Yuko Matsushita , Yuya Sakurai , Takashi Hosokawa , Masahiro N. Machida

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…

太阳与恒星天体物理 · 物理学 2014-07-02 Geoffroy Lesur , Matthew W. Kunz , Sebastien Fromang

We discuss a hydrodynamical model for the dispersal of protoplanetary discs around young, low mass (<1.5 M_sun) stars by photoevaporation from the central object's energetic radiation, which considers the far-ultraviolet as well as the…

太阳与恒星天体物理 · 物理学 2015-06-03 James E. Owen , Cathie J. Clarke , Barbara Ercolano

Global evolution and dispersal of protoplanetary disks (PPDs) is governed by disk angular momentum transport and mass-loss processes. Recent numerical studies suggest that angular momentum transport in the inner region of PPDs is largely…

地球与行星天体物理 · 物理学 2016-03-09 Xue-Ning Bai , Jiani Ye , Jeremy Goodman , Feng Yuan

By performing local three-dimensional MHD simulations of stratified accretion disks, we investigate disk winds driven by MHD turbulence. Initially given weak vertical magnetic fields are effectively amplified by magnetorotational…

天体物理学 · 物理学 2015-05-13 T. K. Suzuki , S. Inutsuka

The Hall effect is recently shown to be efficient in magnetized dense molecular cores, and could lead to a bimodal formation of rotationally supported discs (RSDs) in the first core phase. However, how such Hall dominated systems evolve in…

太阳与恒星天体物理 · 物理学 2020-09-17 Bo Zhao , Paola Caselli , Zhi-Yun Li , Ruben Krasnopolsky , Hsien Shang , Ka Ho Lam

The mechanisms of angular momentum transport and level of turbulence in protoplanetary disks (PPDs) are crucial for understanding many aspects of planet formation. In the recent years, it has been realized that the magneto-rotational…

地球与行星天体物理 · 物理学 2020-03-11 Can Cui , Xue-Ning Bai

The magnetorotational instability (MRI) is the most promising mechanism by which angular momentum is efficiently transported outwards in astrophysical discs. However, its application to protoplanetary discs remains problematic. These discs…

地球与行星天体物理 · 物理学 2015-06-16 Matthew W. Kunz , Geoffroy Lesur

High resolution X-ray spectra of black hole X-ray binaries (BHBs) show blueshifted absorption lines from disk winds which seem to be equatorial. Winds occur in the Softer (disk-dominated) states of the outburst and are less prominent or…

高能天体物理现象 · 物理学 2016-04-27 S. Chakravorty , P-O. Petrucci , J. Ferreira , G. Henri , R. Belmont , M. Clavel , S. Corbel , J. Rodriguez , M. Coriat , S. Drappeau , J. Malzac

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…

地球与行星天体物理 · 物理学 2015-08-06 Sarah L. Keith , Mark Wardle

We study the evolution of the protoplanetary discs (PPDs) in the presence of magnetically driven winds with the stress relations motivated by the non-ideal MHD disc simulations. Contribution of the magnetic winds in the angular momentum…

星系天体物理 · 物理学 2019-07-31 Mohsen Shadmehri , Sayyedeh Masoumeh Ghoreyshi