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相关论文: The Angular Momentum of Magnetized Molecular Cloud…

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We present a detailed study of the collapse of molecular cloud cores using high resolution 3D adaptive mesh refinement (AMR) numerical simulations. In this first in a series of investigations our initial conditions consists of spherical…

天体物理学 · 物理学 2009-11-10 Robi Banerjee , Ralph E. Pudritz , Lindsay Holmes

We run numerical simulations of molecular clouds (MCs), adopting properties similar to those found in the Central Molecular Zone (CMZ) of the Milky Way. For this, we employ the moving mesh code Arepo and perform simulations which account…

星系天体物理 · 物理学 2016-09-21 Erik Bertram , Simon C. O. Glover , Paul C. Clark , Sarah E. Ragan , Ralf S. Klessen

Molecular clouds are observed to be turbulent, but the origin of this turbulence is not well understood. As a result, there are two different approaches to simulating molecular clouds, one in which the turbulence is allowed to decay after…

天体物理学 · 物理学 2009-11-13 Stella S. R. Offner , Richard I. Klein , Christopher F. McKee

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…

太阳与恒星天体物理 · 物理学 2018-11-28 Y. Tsukamoto , S. Okuzumi , K. Iwasaki , M. N. Machida , S. Inutsuka

Observed molecular clouds often appear to have very low star formation efficiencies and lifetimes an order of magnitude longer than their free-fall times. Their support is attributed to the random supersonic motions observed in them. We…

天体物理学 · 物理学 2010-10-28 Ralf S. Klessen , Fabian Heitsch , Mordecai-Mark Mac Low

We present results of new three-dimensional (3D) general-relativistic magnetohydrodynamic simulations of rapidly rotating strongly magnetized core collapse. These simulations are the first of their kind and include a microphysical…

高能天体物理现象 · 物理学 2015-02-18 P. Mösta , S. Richers , C. D. Ott , R. Haas , A. L. Piro , K. Boydstun , E. Abdikamalov , C. Reisswig , E. Schnetter

We discuss the lifetimes and evolution of dense cores formed as turbulent density fluctuations in magnetized, isothermal molecular clouds. We consider numerical simulations in which we measure the cores' magnetic criticality and Jeans…

天体物理学 · 物理学 2007-05-23 E. Vazquez-Semadeni , J. Kim , M. Shadmehri , J. Ballesteros-Paredes

The magnetic field strength in molecular clouds is a fundamental quantity for theories of star formation. It is estimated by Zeeman splitting measurements in a few dense molecular cores, but its volume--averaged value within large molecular…

天体物理学 · 物理学 2009-11-10 Paolo Padoan , Raul Jimenez , Mika Juvela , Aake Nordlund

We summarize recent numerical results on the control of the star formation efficiency (SFE), addressing the effects of turbulence and the magnetic field strength. In closed-box numerical simulations, the effect of the turbulent Mach number…

天体物理学 · 物理学 2009-11-11 Enrique Vazquez-Semadeni

We perform 2D numerical simulations of a magnetorotational explosion of a rotating magnetized gas cloud. We found that amplification of a toroidal magnetic field due to the differential rotation leads to a transformation of the part of the…

天体物理学 · 物理学 2007-05-23 N. V. Ardeljan , G. S. Bisnovatyi-Kogan , S. G. Moiseenko

We investigate the roles of magnetic fields and ambipolar diffusion during prestellar core formation in turbulent giant molecular clouds (GMCs), using three-dimensional numerical simulations. Our simulations focus on the shocked layer…

太阳与恒星天体物理 · 物理学 2015-06-19 Che-Yu Chen , Eve C. Ostriker

We investigate the core mass distribution (CMD) resulting from numerical models of turbulent fragmentation of molecular clouds. In particular we study its dependence on the sonic root-mean-square Mach number $\Ms$. We analyze simulations…

We use 3D numerical MHD simulations to follow the evolution of cold, turbulent, gaseous systems with parameters representing GMC conditions. We study three cloud simulations with varying mean magnetic fields, but identical initial velocity…

天体物理学 · 物理学 2008-11-26 Eve C. Ostriker , James M. Stone , Charles F. Gammie

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…

太阳与恒星天体物理 · 物理学 2015-06-12 Alan P. Boss , Sandra A. Keiser

We performed sub-parsec ($\sim$ 0.014 pc) scale simulations of cloud-cloud collisions of two idealized turbulent molecular clouds (MCs) with different masses in the range of $0.76 - 2.67 \times 10^4$M$_{\odot}$ and with collision speeds of…

星系天体物理 · 物理学 2018-02-15 Ken Takahira , Kazuhiro Shima , Elizabeth J. Tasker , Asao Habe

Magnetic fields are dynamically important in the diffuse interstellar medium. Understanding how gravitationally bound, star-forming clouds form requires modeling of the fields in a self-consistent, supernova-driven, turbulent, magnetized,…

星系天体物理 · 物理学 2022-02-16 Juan C. Ibáñez-Mejía , Mordecai-Mark Mac Low , Ralf S. Klessen

We present numerical studies of compressible, decaying turbulence, with and without magnetic fields, with initial rms Alfven and Mach numbers ranging up to five, and apply the results to the question of the support of star-forming…

天体物理学 · 物理学 2009-10-30 Mordecai-Mark Mac Low , Ralf S. Klessen , Andreas Burkert , Michael D. Smith

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…

太阳与恒星天体物理 · 物理学 2015-05-28 Fumitaka Nakamura , Zhi-Yun Li

We utilize the more than 100 gravitationally-bound dense cores formed in our three-dimensional, turbulent MHD simulations reported in Chen & Ostriker (2015) to analyze structural, kinematic, and magnetic properties of prestellar cores. Our…

太阳与恒星天体物理 · 物理学 2018-10-10 Che-Yu Chen , Eve C. Ostriker

The collapse and fragmentation of initially filamentary, magnetic molecular clouds is calculated in three dimensions with a gravitational, radiative hydrodynamics code. The code includes magnetic field effects in an approximate manner:…

天体物理学 · 物理学 2015-06-24 Alan P. Boss