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Related papers: Ambipolar Diffusion in Molecular Cloud Cores and t…

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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

We discuss the effects of the magnetic field observed in molecular clouds on the process of star formation, concentrating on the phase of gravitational collapse of low-mass dense cores, cradles of sunlike stars. We summarize recent analytic…

Astrophysics of Galaxies · Physics 2015-06-23 Susana Lizano , Daniele Galli

We investigate the formation and evolution of a first core, protostar, and circumstellar disc with a three-dimensional non-ideal (including both Ohmic and ambipolar diffusion) radiation magnetohydrodynamics simulation. We found that the…

Solar and Stellar Astrophysics · Physics 2015-07-15 Yusuke Tsukamoto , Kazunari Iwasaki , Satoshi Okuzumi , Masahiro N. Machida , Shu-ichiro Inutsuka

A comparison of accretion and (turbulent) magnetic diffusion timescales for sheets and filaments demonstrates that dense star-forming clouds generally will -- under realistic conditions -- become supercritical due to mass accretion on…

Astrophysics of Galaxies · Physics 2015-06-19 Fabian Heitsch , Lee Hartmann

We investigate the jet launching process from accretion disks extending our recent study (paper I) to a truly bipolar setup. We perform axisymmetric MHD simulations of the disk-jet interaction on a computational domain covering both…

High Energy Astrophysical Phenomena · Physics 2015-06-15 Christian Fendt , Somayeh Sheikhnezami

Simulating the long-term evolution of temperature and magnetic fields in neutron stars is a major effort in astrophysics, having significant impact in several topics. A detailed evolutionary model requires, at the same time, the numerical…

High Energy Astrophysical Phenomena · Physics 2021-05-19 Daniele Viganò , Alberto García-García , José A. Pons , Clara Dehman , Vanessa Graber

We investigate the physical properties of dense cores formed in turbulent, magnetized, parsec-scale clumps of molecular clouds, using three-dimensional numerical simulations that include protostellar outflow feedback. The dense cores are…

Solar and Stellar Astrophysics · Physics 2015-05-28 Fumitaka Nakamura , Zhi-Yun Li

We investigate the formation and evolution of isothermal collapse nonuniformity for rotating magnetic interstellar clouds. The initial and boundary conditions correspond to the statement of the problem of homogeneous cloud contraction from…

Astrophysics · Physics 2007-05-23 A. E. Dudorov , A. G. Zhilkin , N. Y. Zhilkina

The evolution of molecular clouds in galactic centres is thought to differ from that in galactic discs due to a significant influence of the external gravitational potential. We present a set of numerical simulations of molecular clouds…

Evolution with mass segregation and the evolution of the rotation of cores are both discussed for self-similar core collapse. Evolution with angular velocity proportional to the square root of the density is predicted. On the Dynamical Main…

Astrophysics · Physics 2007-05-23 Donald Lynden-Bell

We calculate the evolution of molecular line profiles of HCO$^+$ and C$^{18}$O toward a dense core thatis forming inside a magnetized turbulent molecular cloud. Features of the profiles can be affected more significantly by coupled velocity…

Astrophysics of Galaxies · Physics 2009-07-22 Jeong-Eun Lee , Jongsoo Kim

Unopposed radiative cooling in clusters of galaxies results in excessive mass deposition rates. However, the cool cores of galaxy clusters are continuously heated by thermal conduction and turbulent heat diffusion due to minor mergers or…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 M. Ruszkowski , S. Peng Oh

We investigate numerically and semi-analytically the collapse of low-mass, rotating prestellar cores. Initially, the cores are in approximate equilibrium with low rotation (the initial ratio of thermal to gravitational energy is $\alpha_0…

Astrophysics · Physics 2009-11-10 P. Hennebelle , A. Whitworth , S. Cha , S. Goodwin

We present an analytic description of the spherically symmetric gravitational collapse of radiatively cooling gas clouds, which illustrates the mechanism by which radiative cooling induces gravitational instability at a characteristic mass…

Astrophysics of Galaxies · Physics 2025-01-03 James Gurian , Boyuan Liu , Donghui Jeong , Takashi Hosokawa , Shingo Hirano , Naoki Yoshida

In the standard scenario of isolated low-mass star formation, strongly magnetized molecular clouds are envisioned to condense gradually into cores, driven by ambipolar diffusion. Once the cores become magnetically supercritical, they…

Astrophysics · Physics 2007-05-23 Fumitaka Nakamura , Zhi-Yun Li

In this paper the distribution of charged particles is constructed under the approximation of ambipolar diffusion. The results of mathematical modelling in two-dimensional case taking into account the velocities of the system are presented.

Computational Engineering, Finance, and Science · Computer Science 2007-05-23 P. Nefyodov , V. Reztsov , O. Riabinina

Ambipolar diffusion (AD) is believed to be a crucial process for redistributing magnetic flux in the dense molecular gas that occurs in regions of star formation. We carry out numerical simulations of this process in regions of low…

Solar and Stellar Astrophysics · Physics 2015-05-30 Pak Shing Li , Christopher F. McKee , Richard I. Klein

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

Solar prominence threads are typically located around magnetic dips, where cold and dense plasma is suspended against gravity in the hot corona thanks to the upward magnetic force. Because prominences are partially ionized, ambipolar…

Solar and Stellar Astrophysics · Physics 2026-04-08 Llorenç Melis , Roberto Soler

The dense molecular cloud cores that form stars, like other self-gravitating objects, undergo bulk oscillations. Just at the point of gravitational instability, their fundamental oscillation mode has zero frequency. We study, using…

Solar and Stellar Astrophysics · Physics 2009-11-13 Steven W. Stahler , Jeffrey J. Yen