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Related papers: Dependence of Hall Coefficient on Grain Size and C…

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Magnetic fields play an important role in star formation by regulating the removal of angular momentum from collapsing molecular cloud cores. Hall diffusion is known to be important to the magnetic field behaviour at many of the…

Solar and Stellar Astrophysics · Physics 2015-05-30 Catherine R. Braiding , Mark Wardle

Dust grains influence many aspects of star formation, including planet formation, opacities for radiative transfer, chemistry, and the magnetic field via Ohmic, Hall, and ambipolar diffusion. The size distribution of the dust grains is the…

Solar and Stellar Astrophysics · Physics 2023-02-08 Pierre Marchand , Ugo Lebreuilly , Mordecai-Mark Mac Low , Vincent Guillet

We study the formation and early evolution of young stellar objects (YSOs) using three-dimensional non-ideal magnetohydrodynamic (MHD) simulations to investigate the effect of cosmic ray ionization rate and dust fraction (or amount of dust…

Earth and Planetary Astrophysics · Physics 2023-03-15 Yudai Kobayashi , Daisuke Takaishi , Yusuke Tsukamoto

Magnetic fields play an important role in star formation by regulating the removal of angular momentum from collapsing molecular cloud cores. Hall diffusion is known to be important to the magnetic field behaviour at many of the…

Solar and Stellar Astrophysics · Physics 2011-10-12 Catherine Braiding

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…

Solar and Stellar Astrophysics · Physics 2020-09-17 Bo Zhao , Paola Caselli , Zhi-Yun Li , Ruben Krasnopolsky , Hsien Shang , Ka Ho Lam

The grand question of star and planet formation is the distribution of magnetic flux in the protoplanetary disks. To answer it, a detailed self-consistent chemical evolution is needed to describe the magnetic dissipation in the collapsing…

Solar and Stellar Astrophysics · Physics 2017-07-26 Natalia Dzyurkevich , Benoit Commercon , Pierre Lesaffre , Dimitry Semenov

Grain growth by the accretion of metals in interstellar clouds (called `grain growth') could be one of the dominant processes that determine the dust content in galaxies. The importance of grain size distribution for the grain growth is…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Hiroyuki Hirashita , Tzu-Ming Kuo

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…

Solar and Stellar Astrophysics · Physics 2021-05-12 Bo Zhao , Paola Caselli , Zhi-Yun Li , Ruben Krasnopolsky , Hsien Shang , Ka Ho Lam

Dust constitutes only about one percent of the mass of circumstellar disks, yet it is of crucial importance for the modeling of planet formation, disk chemistry, radiative transfer and observations. The initial growth of dust from…

Earth and Planetary Astrophysics · Physics 2011-07-19 T. Birnstiel

We investigate the possibility of the growth of magnetorotational instability (MRI) in disks around Class 0 protostars. We construct a disk model and calculate the chemical reactions of neutral and charged atoms, molecules and dust grains…

Solar and Stellar Astrophysics · Physics 2021-05-12 Yoshihiro Kawasaki , Shunta Koga , Masahiro N. Machida

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

We developed a chemical network for modeling the chemistry and non-ideal MHD effects from the collapsing dense molecular clouds to protostellar disks. First, we re-formulated the cosmic-ray desorption rate by considering the variations of…

Solar and Stellar Astrophysics · Physics 2018-05-16 Bo Zhao , Paola Caselli , Zhi-Yun Li

The formation of protostellar discs is severely hampered by magnetic braking, as long as magnetic fields remain frozen in the gas. The latter condition depends on the levels of ionisation that characterise the innermost regions of a…

Astrophysics of Galaxies · Physics 2015-06-22 Marco Padovani , Daniele Galli , Patrick Hennebelle , Benoît Commerçon , Marc Joos

We investigate the impact of radiation pressure on spatial dust distribution inside H$_\mathrm{II}$ regions using one-dimensional radiation hydrodynamic simulations, which include absorption and re-emission of photons by dust. In order to…

Astrophysics of Galaxies · Physics 2017-11-21 Shohei Ishiki , Takashi Okamoto , Akio K. Inoue

The degree of coupling between the gas and the magnetic field during the collapse of a core and the subsequent formation of a disk depends on the assumed dust size distribution. We study the impact of grain-grain coagulation on the…

Astrophysics of Galaxies · Physics 2020-10-28 V. Guillet , P. Hennebelle , G. Pineau des Forêts , A. Marcowith , B. Commerçon , P. Marchand

Interstellar dust grains can be spun up by radiative torques, and the resulting centrifugal force may be strong enough to disrupt large dust grains. We examine the effect of this rotational disruption on the evolution of grain size…

Astrophysics of Galaxies · Physics 2020-04-08 Hiroyuki Hirashita , Thiem Hoang

Recent research on the buildup of rocks from small dust grains has reaffirmed that grain growth in protoplanetary disks should occur quickly. Calculation of growth rates have been made for a variety of growth processes and generally predict…

Astrophysics · Physics 2007-05-23 Steven V. W. Beckwith , Thomas Henning , Yoshitsugu Nakagawa

Dust grains grow in interstellar clouds by accretion and coagulation. In this paper, we focus on these two grain growth processes and numerically investigate how they interplay to increase the grain radii. We show that accretion efficiently…

Astrophysics of Galaxies · Physics 2015-06-04 Hiroyuki Hirashita

We model the effect of grain size distribution in a galaxy on the evolution of CO and H$_2$ abundances. The formation and dissociation of CO and H$_2$ in typical dense clouds are modelled in a manner consistent with the grain size…

Astrophysics of Galaxies · Physics 2023-05-10 Hiroyuki Hirashita

Cosmic rays and cosmic ray induced photons are vital components of chemical evolution in areas of interstellar medium that are impenetrable by external ultraviolet radiation. However, rates of reactions with cosmic ray induced photons used…

Earth and Planetary Astrophysics · Physics 2025-05-06 L. N. Zwicky , T. S. Molyarova
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