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Related papers: Star Formation in Cold, Spherical, Magnetized Mole…

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We formulate the problem of the formation and subsequent evolution of fragments (or cores) in magnetically-supported, self-gravitating molecular clouds in two spatial dimensions. The six-fluid (neutrals, electrons, molecular and atomic…

Astrophysics · Physics 2011-02-11 Matthew W. Kunz , Telemachos Ch. Mouschovias

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

We present a unified model for molecular core formation and evolution, based on numerical simulations of converging, supersonic flows. Our model applies to star formation in GMCs dominated by large-scale turbulence, and contains four main…

Solar and Stellar Astrophysics · Physics 2009-06-25 Hao Gong , Eve C. Ostriker

The accretion phase of star formation is investigated in magnetically-dominated clouds that have an initial subcritical mass-to-flux ratio. We employ nonideal magnetohydrodynamic simulations that include ambipolar diffusion and ohmic…

Solar and Stellar Astrophysics · Physics 2020-03-18 Masahiro N. Machida , Shantanu Basu

We investigate the formation and evolution of giant molecular clouds (GMCs) by the collision of convergent warm neutral medium (WNM) streams in the interstellar medium, in the presence of magnetic fields and ambipolar diffusion (AD),…

We formulate the problem of the formation and collapse of nonaxisymmetric protostellar cores in weakly ionized, self-gravitating, magnetic molecular clouds. In our formulation, molecular clouds are approximated as isothermal, thin (but with…

Astrophysics · Physics 2011-02-11 Glenn E. Ciolek , Shantanu Basu

We study the non-axisymmetric evolution of magnetized clouds, using a 2D MHD code based on the physically motivated thin-disk approximation. We found that such clouds become unstable to non-axisymmetric perturbations after the supercritical…

Astrophysics · Physics 2009-11-07 Fumitaka Nakamura , Zhi-Yun Li

We use magnetohydrodynamical simulations of converging flows to investigate the process of molecular cloud formation and evolution out of the magnetised ISM. Here, we investigate whether the observed subcritical HI clouds can become…

Astrophysics of Galaxies · Physics 2015-06-02 Bastian Körtgen , Robi Banerjee

(Abridged) Aims & Methods. A two-dimensional, semi-analytical model is presented that follows, for the first time, the chemical evolution from a collapsing molecular cloud (a pre-stellar core) to a protostar and circumstellar disk. The…

Solar and Stellar Astrophysics · Physics 2009-11-13 R. Visser , E. F. van Dishoeck , S. D. Doty , C. P. Dullemond

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

We demonstrate that the formation of collapsing cores in subcritical clouds is accelerated by nonlinear flows, by performing three-dimensional non-ideal MHD simulations. An initial random supersonic (and trans-Alfvenic) turbulent-like flow…

Astrophysics · Physics 2009-11-13 Takahiro Kudoh , Shantanu Basu

We investigate protostellar collapse of molecular cloud cores by numerical simulations, taking into account turbulence and magnetic fields. By using the adaptive mesh refinement technique, the collapse is followed over a wide dynamic range…

Solar and Stellar Astrophysics · Physics 2015-05-19 Tomoaki Matsumoto , Tomoyuki Hanawa

In the standard picture of isolated star formation, dense ``starless'' cores are formed out of magnetic molecular clouds due to ambipolar diffusion. Under the simplest spherical geometry, I demonstrate that ``starless'' cores formed this…

Astrophysics · Physics 2009-10-31 Zhi-Yun Li

We have begun a systematic numerical study of the nonlinear growth of nonaxisymmetric perturbations during the ambipolar diffusion-driven evolution of initially magnetically subcritical molecular clouds, with an eye on the formation of…

Astrophysics · Physics 2009-11-07 Fumitaka Nakamura , Zhi-Yun Li

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 revisit the problem of the formation of dense protostellar cores due to ambipolar diffusion within magnetically supported molecular clouds, and derive an analytical expression for the core formation timescale. The resulting expression is…

Astrophysics · Physics 2009-10-31 Glenn E. Ciolek , Shantanu Basu

Theoretically, stars have been formed from the collapse of cores in the molecular clouds. Historically, the core had been assumed as an singular isothermal sphere (SIS), and the collapse had been investigated by a self-similar manner. This…

Astrophysics of Galaxies · Physics 2015-05-19 Mohsen Nejad-Asghar

A physical model and two-dimensional numerical method for computing the evolution and spectra of protostellar clouds are described. The physical model is based on a system of magneto-gasdynamical equations, including ohmic and ambipolar…

Instrumentation and Methods for Astrophysics · Physics 2015-05-13 A. G. Zhilkin , Ya. N. Pavlyuchenkov , S. N. Zamozdra

We study the self-similar collapse of an isothermal magnetized rotating cloud in the ideal magnetohydrodynamic (MHD) regime. In the limit of small distance from the accreting protostar we find an analytic solution that corresponds to…

Astrophysics · Physics 2008-11-26 D. Galli , S. Lizano , F. H. Shu , A. Allen

We investigate molecular evolution in a star-forming core that is initially a hydrostatic starless core and collapses to form a low-mass protostar. The results of a one-dimensional radiation-hydrodynamics calculation are adopted as a…

Astrophysics · Physics 2009-11-13 Yuri Aikawa , Valentine Wakelam , Robin T. Garrod , Eric Herbst