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Related papers: Disk Formation in Magnetized Clouds Enabled by the…

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Many mechanisms have been proposed to alleviate the magnetic catastrophe, which prevents the Keplerian disk from forming inside a collapsing magnetized core. Such propositions include inclined field and non-ideal magnetohydrodynamics…

Earth and Planetary Astrophysics · Physics 2024-01-08 Yueh-Ning Lee , Barshan Ray , Pierre Marchand , Patrick Hennebelle

The Hall effect plays a significant role in star formation because it induces rotation in the infalling envelope, which in turn affects the formation and evolution of the circumstellar disk. The importance of the Hall effect varies with the…

Solar and Stellar Astrophysics · Physics 2019-01-09 Shunta Koga , Yusuke Tsukamoto , Satoshi Okuzumi , Masahiro N. Machida

We present an idealized, spherical model of the evolution of a magnetized molecular cloud due to ambipolar diffusion. This model allows us to follow the quasi-static evolution of the cloud's core prior to collapse and the subsequent…

Astrophysics · Physics 2009-10-30 P. N. Safier , C. F. McKee , S. W. Stahler

Angular momentum transport in protostellar disks can be achieved by the action of a large scale magnetic field that runs vertically through the disk. The magnetic field centrifugally drives material from the disk surfaces into a wind,…

Astrophysics · Physics 2008-02-03 Mark Wardle

We investigate the effects of magnetic fields and radiative protostellar feedback on the star formation process using self-gravitating radiation magnetohydrodynamical calculations. We present results from a series of calculations of the…

Solar and Stellar Astrophysics · Physics 2015-05-13 Daniel J. Price , Matthew R. Bate

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 perform a long-term simulation of star and disk formation using three-dimensional non-ideal magnetohydrodynamics. The simulation starts from a prestellar cloud and proceeds through the long-term evolution of the circumstellar disk until…

Solar and Stellar Astrophysics · Physics 2024-05-15 Masahiro N. Machida , Shantanu Basu

The origin of disks surrounding young stars has direct implications for our understanding of the formation of planetary systems. In the interstellar clouds from which star form, angular momentum is regulated by magnetic fields, preventing…

Astrophysics · Physics 2007-05-23 Michiel R. Hogerheijde

Magnetic fields are known to be dynamically important in the interstellar medium of our own Galaxy, and they are ubiquitously observed in diffuse gas in the halos of galaxies and galaxy clusters. Yet, magnetic fields have typically been…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-05 R. Pakmor , V. Springel

In this chapter we review recent advances in understanding the roles that magnetic fields play throughout the star formation process, gained through observations and simulations of molecular clouds, the dense, star-forming phase of the…

Astrophysics of Galaxies · Physics 2022-03-22 Kate Pattle , Laura Fissel , Mehrnoosh Tahani , Tie Liu , Evangelia Ntormousi

We formulate the problem of the formation of magnetically supercritical cores in magnetically subcritical parent molecular clouds, and the subsequent collapse of the cores to high densities, past the detachment of ions from magnetic field…

Astrophysics · Physics 2011-02-11 Konstantinos Tassis , Telemachos Ch. Mouschovias

The history of star formation in the strong gravitational potential of the Galactic center has been of much interest, recently. We propose that the sub-parsec-scale disk of massive stars orbiting the massive black hole at the Galactic…

Astrophysics · Physics 2007-12-11 F. Yusef-Zadeh , M. Wardle

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

Stars are thought to form predominantly within filamentary molecular clouds. Recent studies have suggested that active star formation, including the formation of stellar clusters and massive stars, occurs within so-called "hub" structures,…

Astrophysics of Galaxies · Physics 2026-05-21 Raiga Kashiwagi , Kazunari Iwasaki , Kohji Tomisaka , Tsuyoshi Inoue

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

This is the first paper about the fragmentation and mass outflow in the molecular cloud by using three-dimensional MHD nested-grid simulations. The binary star formation process is studied paying particular attention to the fragmentation of…

Astrophysics · Physics 2009-11-10 Masahiro N Machida , Kohji Tomisaka , Tomoaki Matsumoto

The protostellar outflows have indispensable role in the formation of single stars, because they carry off the excess angular momentum from the centre of the shrinking gas cloud, and permits further collapse to form a star. On the other…

Solar and Stellar Astrophysics · Physics 2015-05-13 Masahiro N. Machida , Shu-ichiro Inutsuka , Tomoaki Matsumoto

Molecular clouds, the birthplaces of stars in galaxies, form dynamically from the diffuse atomic gas of the interstellar medium (ISM). The ISM is also threaded by magnetic fields which have a large impact on its dynamics. In particular,…

Astrophysics of Galaxies · Physics 2015-09-14 Robi Banerjee , Bastian Körtgen

We examined the gravitational contraction of isothermal molecular cloud cores with slow rotation by means of two-dimensional numerical simulations. Applying a sink-cell method, we followed the evolution of the cloud cores up to the stages…

Astrophysics · Physics 2009-10-31 Fumitaka Nakamura

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