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Related papers: Flow-Driven Cloud Formation and Fragmentation: Res…

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We present the results of a series of numerical simulations of compressible, self-gravitating hydrodynamic turbulence of cluster-forming clumps in molecular clouds. We examine the role that turbulence has in the formation of gravitationally…

Astrophysics · Physics 2009-11-10 David A. Tilley , Ralph E. Pudritz

We investigate, by means of numerical simulations, the phenomenology of star formation triggered by low-velocity collisions between low-mass molecular clumps. The simulations are performed using an SPH code which satisfies the Jeans…

Astrophysics · Physics 2008-11-26 S. Kitsionas , A. P. Whitworth

Condensational growth of cloud droplets due to supersaturation fluctuations is investigated by solving the hydrodynamic and thermodynamic equations using direct numerical simulations with droplets being modeled as Lagrangian particles. The…

Atmospheric and Oceanic Physics · Physics 2019-02-20 Xiang-Yu Li , Gunilla Svensson , Axel Brandenburg , Nils E. L. Haugen

We present Smoothed Particle Hydrodynamics (SPH) simulations of molecular cloud formation in spiral galaxies. These simulations model the response of a non-self-gravitating gaseous disk to a galactic potential. The spiral shock induces high…

Astrophysics · Physics 2009-11-11 C. L. Dobbs , I. A. Bonnell , J. E. Pringle

Recent simulations of self-gravitating accretion discs, carried out using a three-dimensional Smoothed Particle Hydrodynamics (SPH) code by Meru and Bate, have been interpreted as implying that three-dimensional global discs fragment much…

Earth and Planetary Astrophysics · Physics 2015-06-03 W. K. M. Rice , D. H. Forgan , P. J. Armitage

Turbulence is argued to play a crucial role in cloud droplet growth. The combined problem of turbulence and cloud droplet growth is numerically challenging. Here, an Eulerian scheme based on the Smoluchowski equation is compared with two…

Fluid Dynamics · Physics 2017-08-01 Xiang-Yu Li , A. Brandenburg , N. E. L. Haugen , G. Svensson

This paper describes 3D simulations of the formation of collapsing cold clumps via thermal instability inside a larger cloud complex. The initial condition was a diffuse atomic, stationary, thermally unstable, 200pc diameter spherical cloud…

Astrophysics of Galaxies · Physics 2019-03-20 C. J. Wareing , S. A. E. G. Falle , J. M. Pittard

Recently it has been suggested that the fragmentation boundary in Smoothed Particle Hydrodynamic (SPH) and FARGO simulations of self-gravitating accretion discs with beta-cooling do not converge as resolution is increased. Furthermore, this…

Earth and Planetary Astrophysics · Physics 2015-06-18 W. K. M. Rice , S. -J. Paardekooper , D. H. Forgan , P. J. Armitage

Observational evidence from local star-forming regions mandates that star formation occurs shortly after, or even during, molecular cloud formation. Models of the formation of molecular clouds in large-scale converging flows have identified…

Astrophysics of Galaxies · Physics 2015-05-27 Jonathan Carroll-Nellenback , Adam Frank , Fabian Heitsch

We study gravitational collapse of low-metallicity gas clouds and the formation of protostars by three-dimensional hydrodynamic simulations. Grain growth, non-equilibrium chemistry, molecular cooling, and chemical heating are solved in a…

Astrophysics of Galaxies · Physics 2018-08-30 Gen Chiaki , Naoki Yoshida , Shingo Hirano

We use SPH simulations with an approximate radiative cooling prescription to model evolution of a massive and large ($\sim 100$ AU) very young protoplanetary disc. We also model dust growth and gas-grain dynamics with a second fluid…

Earth and Planetary Astrophysics · Physics 2015-05-20 Seung-Hoon Cha , Sergei Nayakshin

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…

Astrophysics · Physics 2010-10-28 Ralf S. Klessen , Fabian Heitsch , Mordecai-Mark Mac Low

The streaming instability is a promising mechanism for planetesimal formation. The instability can rapidly form dense clumps that collapse self-gravitationally, which is efficient for large dust grains with the Stokes number on the order of…

Earth and Planetary Astrophysics · Physics 2025-03-04 Ryosuke T. Tominaga , Hidekazu Tanaka

To date, most numerical simulations of molecular clouds, and star formation within them, assume a uniform density sphere or box with an imposed turbulent velocity field. In this work, we select molecular clouds from galactic scale…

Astrophysics of Galaxies · Physics 2015-06-23 Ramon Rey-Raposo , Clare Dobbs , Ana Duarte-Cabral

We report on the filaments that develop self-consistently in a new numerical simulation of cloud formation by colliding flows. As in previous studies, the forming cloud begins to undergo gravitational collapse because it rapidly acquires a…

Astrophysics of Galaxies · Physics 2015-06-17 Gilberto C. Gomez , Enrique Vazquez-Semadeni

Sheet-like clouds are common in turbulent gas and perhaps form via collisions between turbulent gas flows. Having examined the evolution of an isothermal shocked slab in an earlier contribution, in this work we follow the evolution of a…

Astrophysics of Galaxies · Physics 2015-06-23 S. Anathpindika

We report on the results of the first 3D SPH simulation of massive, gravitationally unstable protoplanetary disks with radiative transfer. We adopt a flux-limited diffusion scheme justified by the high opacity of most of the disk. The…

Astrophysics · Physics 2009-11-11 Lucio Mayer , Graeme Lufkin , Thomas Quinn , James Wadsley

Using self-gravitational hydrodynamical numerical simulations, we investigated the evolution of high-density turbulent molecular clouds swept by a colliding flow. The interaction of shock waves due to turbulence produces networks of thin…

Solar and Stellar Astrophysics · Physics 2015-06-23 Tomoaki Matsumoto , Kazuhito Dobashi , Tomomi Shimoikura

We perform SPH simulations of the collapse and fragmentation of low-mass cores having different initial levels of turbulence (alpha_turb=0.05,0.10,0.25). We use a new treatment of the energy equation which captures the transport of cooling…

Astrophysics · Physics 2009-11-13 R. E. Attwood , S. P. Goodwin , D. Stamatellos , A. P. Whitworth

We investigate the evolution of angular momentum in SPH simulations of galaxy formation, paying particular attention to artificial numerical effects. We find that a cold gas disc forming in an ambient hot gas halo receives a strong…

Astrophysics · Physics 2009-11-10 T. Okamoto , A. Jenkins , V. R. Eke , V. Quilis , C. S. Frenk