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We study numerically the collapse of rotating, magnetized molecular cloud cores, focusing on rotation and magnetic braking during the main accretion phase of isolated star formation. Motivated by previous numerical work and analytic…

Astrophysics · Physics 2009-11-10 A. Allen , Z. Y. Li , F. H. Shu

A systematic study of the linear thermal instability of a self-gravitating magnetic molecular cloud is carried out for the case when the unperturbed background is subject to local expansion or contraction. We consider the ambipolar…

Astrophysics · Physics 2009-11-11 Mohsen Nejad-Asghar , Jamshid Ghanbari

We present measurements of the mean dense core lifetimes in numerical simulations of magnetically supercritical, turbulent, isothermal molecular clouds, in order to compare with observational determinations. "Prestellar" lifetimes (given as…

We consider the dynamical evolution of an interstellar cloud that is initially in thermal equilibrium in the warm phase and is then subjected to a sudden increase in the pressure of its surroundings. We find that if the initial plasma beta…

Astrophysics · Physics 2009-11-13 A. J. Lim , S. A. E. G. Falle , T. W. Hartquist

We construct spherical, hydrostatic models of dense molecular cores and Bok globules consisting of two distinct, spatially separate gas components: a central, isothermal region surrounded by a negative-index, polytropic envelope. The clouds…

Astrophysics · Physics 2009-10-31 Charles L. Curry , Christopher F. McKee

We investigate, through a series of numerical calculations, the evolution of dense cores that are accreting external gas up to and beyond the point of star formation. Our model clouds are spherical, unmagnetized configurations with fixed…

Solar and Stellar Astrophysics · Physics 2015-06-16 Motahareh Mohammadpour , Steven W. Stahler

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…

We investigate the role of non-isothermality in gravitational collapse and protostellar accretion by explicitly including the effects of molecular radiative cooling, gas-dust energy transfer, and cosmic ray heating in models of spherical…

Astrophysics · Physics 2009-11-13 E. I. Vorobyov , Shantanu Basu

Aims: We aim to derive a stability condition for non-isothermal Bonnor-Ebert spheres and compare the physical properties of critical non-isothermal and isothermal gas spheres. These configurations can serve as models for prestellar cores…

Astrophysics of Galaxies · Physics 2015-05-30 O. Sipilä , J. Harju , M. Juvela

Star formation through the dynamical magnetized collapse remains an active area of astrophysical research. We carry out a comprehensive exploration on the magnetized gravitational collapse of a non-rotating self-gravitating initially…

Astrophysics of Galaxies · Physics 2025-03-31 Indrani Das , Hsien Shang , Ruben Krasnopolsky

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 report the results of our three-dimensional radiation hydrodynamics simulation of collapsing unmagnetized molecular cloud cores. We investigate the formation and evolution of the circumstellar disk and the clumps formed by disk…

Solar and Stellar Astrophysics · Physics 2015-06-16 Yusuke Tsukamoto , Masahiro N. Machida , Shuichiro Inutsuka

Observations of both star-forming regions and young, gas-free stellar associations indicate that most nearby molecular clouds form stars only over a short time span before dispersal; large-scale flows in the diffuse interstellar medium have…

Astrophysics · Physics 2008-11-26 Lee Hartmann , Javier Ballesteros-Paredes , Edwin A. Bergin

We propose that inward, subsonic flows arise from the local dissipation of turbulent motions in molecular clouds. Such "turbulent cooling flows" may account for recent observations of spatially extended inward motions towards dense cores.…

Astrophysics · Physics 2009-10-31 P. Myers , A. Lazarian

For a molecular cloud clump to form stars some transport of magnetic flux is required from the denser, inner regions to the outer regions of the cloud, otherwise this can prevent the collapse. Fast magnetic reconnection which takes place in…

High Energy Astrophysical Phenomena · Physics 2015-06-11 M. R. M. Leão , E. M. de Gouveia Dal Pino , R. Santos-Lima , A. Lazarian

We study numerically the formation of molecular clouds in large-scale colliding flows including self-gravity. The models emphasize the competition between the effects of gravity on global and local scales in an isolated cloud. Global…

We simulate the early stages of the evolution of turbulent, virialized, high-mass protostellar cores, with primary attention to how cores fragment, and whether they form a small or large number of protostars. Our simulations use the Orion…

Astrophysics · Physics 2008-11-26 Mark R. Krumholz , Richard I. Klein , Christopher F. McKee

To understand the formation of a magnetically dominated molecular cloud out of an atomic cloud, we follow the dynamical evolution of the cloud with a time-dependent axisymmetric magnetohydrodynamic code. A thermally stable warm atomic cloud…

Astrophysics · Physics 2009-11-13 S. Van Loo , S. A. E. G. Falle , T. W. Hartquist , T. J. T. Moore

As part of a series of papers aimed at understanding the evolution of the Milky Way's Central Molecular Zone (CMZ), we present hydrodynamical simulations of turbulent molecular clouds orbiting in an accurate model of the gravitational…

Astrophysics of Galaxies · Physics 2019-04-10 James E. Dale , J. M. Diederik Kruijssen , S. N. Longmore

A spherically symmetric hydrodynamic stellar core collapse under gravity is time-dependent and may become unstable once disturbed. Specifically for a homologously collapse of stellar core characterized by a polytropic exponent \Gamma=4/3,…

Solar and Stellar Astrophysics · Physics 2013-10-10 Yu-Qing Lou , Biao Lian
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