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We present results from radiation non-ideal magnetohydrodynamics (MHD) calculations that follow the collapse of rotating, magnetised, molecular cloud cores to stellar densities. These are the first such calculations to include all three…

Solar and Stellar Astrophysics · Physics 2018-02-07 James Wurster , Matthew R. Bate , Daniel J. Price

We investigate whether or not the low ionisation fractions in molecular cloud cores can solve the `magnetic braking catastrophe', where magnetic fields prevent the formation of circumstellar discs around young stars. We perform…

Solar and Stellar Astrophysics · Physics 2016-02-03 James Wurster , Daniel J. Price , Matthew R. Bate

Magnetic fields have been shown both observationally and through theoretical work to be an important factor in the formation of protostars and their accretion disks. Accurate modelling of the evolution of the magnetic field in…

Non-ideal MHD effects are thought to be a crucial component of the star-formation process. Numerically, several complications render the study of non-ideal MHD effects in 3D simulations extremely challenging and hinder our efforts of…

Astrophysics of Galaxies · Physics 2025-02-12 E. Agianoglou , A. Tritsis , K. Tassis

We investigate the effect of non-ideal magnetohydrodynamics (MHD) on the formation of binary stars using a suite of three-dimensional smoothed particle magnetohydrodynamics simulations of the gravitational collapse of one solar mass,…

Solar and Stellar Astrophysics · Physics 2016-12-08 James Wurster , Daniel J. Price , Matthew R. Bate

We model molecular cloud fragmentation with thin disk non-ideal magnetohydrodynamic simulations that include ambipolar diffusion and partial ionization that transitions from primarily ultraviolet dominated to cosmic ray dominated regimes.…

Solar and Stellar Astrophysics · Physics 2015-06-17 Nicole D. Bailey , Shantanu Basu

We report the first three-dimensional radiation magnetohydrodynamic (RMHD) simulations of protostellar collapse with and without Ohmic dissipation.We take into account many physical processes required to study star formation processes,…

Solar and Stellar Astrophysics · Physics 2015-03-20 Kengo Tomida , Kohji Tomisaka , Tomoaki Matsumoto , Yasunori Hori , Satoshi Okuzumi , Masahiro N. Machida , Kazuya Saigo

We present the results of a large suite of three-dimensional (3D) models of the collapse of magnetic molecular cloud cores using the adaptive mesh refinement (AMR) code Enzo2.2 in the ideal magnetohydrodynamics (MHD) approximation. The…

Solar and Stellar Astrophysics · Physics 2015-06-22 A. P. Boss , S. A. Keiser

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

We perform numerical magnetohydrodynamic (MHD) simulations of the gravitational collapse and fragmentation of a cylindrical molecular cloud with the help of the FLASH code. The cloud collapses rapidly along its radius without any signs of…

Astrophysics of Galaxies · Physics 2024-05-15 I. M. Sultanov , S. A. Khaibrakhmanov

We demonstrate the formation of gravitationally unstable discs in magnetized molecular cloud cores with initial mass-to-flux ratios of 5 times the critical value, effectively solving the magnetic braking catastrophe. We model the…

Solar and Stellar Astrophysics · Physics 2018-08-22 James Wurster , Matthew R. Bate , Daniel J. Price

We have performed smoothed particle radiation magnetohydrodynamics (SPRMHD) simulations of the collapse of rotating, magnetised molecular cloud cores to form protostars. The calculations follow the formation and evolution of the first…

Solar and Stellar Astrophysics · Physics 2015-06-17 Matthew R. Bate , Terrence S. Tricco , Daniel J. Price

Resolution studies of test problems set baselines and help define minimum resolution requirements, however, resolution studies must also be performed on scientific simulations to determine the effect of resolution on the specific scientific…

Solar and Stellar Astrophysics · Physics 2019-07-01 James Wurster , Matthew R. Bate

Cosmic rays (CR) play an important role in dense molecular cores, affecting their thermal and dynamical evolution and initiating the chemistry. Several studies have shown that the formation of protostellar discs in collapsing clouds is…

Astrophysics of Galaxies · Physics 2015-06-17 Marco Padovani , Patrick Hennebelle , Daniele Galli

Magnetic fields are important contributers to the dynamics of collapsing molecular cloud cores, and can have a major effect on whether collapse results in a single protostar or fragmentation into a binary or multiple protostar system. New…

Solar and Stellar Astrophysics · Physics 2015-06-12 Alan P. Boss , Sandra A. Keiser

We investigate the effect of numerical magnetic diffusion in magnetohydrodynamic simulations of magnetically supported molecular clouds. To this end, we have performed numerical studies on adaptive mesh isothermal simulations of marginally…

Astrophysics of Galaxies · Physics 2022-01-26 Guido Granda-Muñoz , Enrique Vázquez-Semadeni , Gilberto C. Gómez , Manuel Zamora-Avilés

From molecular clouds to protoplanetary disks, non-ideal magnetic effects are important in many astrophysical environments. Indeed, in star and disk formation processes, it has become clear that these effects are critical to the evolution…

Astrophysics of Galaxies · Physics 2019-01-16 T. Grassi , M. Padovani , J. P. Ramsey , D. Galli , N. Vaytet , B. Ercolano , T. Haugboelle

The effect of misalignment between the magnetic field $\magB$ and the angular momentum $\Jang$ of molecular cloud cores on the angular momentum evolution during the gravitational collapse is investigated by ideal and non-ideal MHD…

Solar and Stellar Astrophysics · Physics 2018-11-28 Y. Tsukamoto , S. Okuzumi , K. Iwasaki , M. N. Machida , S. Inutsuka

Collapse of the rotating magnetized molecular cloud core is studied with the axisymmetric magnetohydrodynamical (MHD) simulations. Due to the change of the equation of state of the interstellar gas, the molecular cloud cores experience…

Astrophysics · Physics 2009-11-06 Kohji Tomisaka

We present results from the first radiation non-ideal magnetohydrodynamics (MHD) simulations of low-mass star cluster formation that resolve the fragmentation process down to the opacity limit. We model 50~M$_\odot$ turbulent clouds…

Solar and Stellar Astrophysics · Physics 2019-08-12 James Wurster , Matthew R. Bate , Daniel J. Price
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