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This article discusses a potential impact of turbulent velocity fluctuations of the air on a drizzle formation in Cumulus clouds. Two different representations of turbulent velocity fluctuations for a microphysics formulated in a Lagrangian…

Atmospheric and Oceanic Physics · Physics 2015-09-07 M. Andrejczuk , A. Gadian , A. Blyth

Using the 3D density distribution derived from the 3D dust map of the solar neighborhood, the gravitational potential is obtained by solving the Poisson equation, from which the tidal tensor is computed. In the optimal decomposition, the…

Astrophysics of Galaxies · Physics 2025-03-24 J. W. Zhou

Gravitational stability of a disc consisting of the gaseous and the stellar components are studied in the linear regime when the gaseous component is turbulent. A phenomenological approach is adopted to describe the turbulence, in which not…

Astrophysics of Galaxies · Physics 2015-06-03 Mohsen Shadmehri , Fazeleh Khajenabi

The process of galaxy cluster formation likely leaves an imprint on the properties of its individual member galaxies. Understanding this process is essential for uncovering the evolutionary connections between galaxies and cosmic…

Gravity plays a determining role in the evolution of the molecular ISM. In \citet{2016arXiv160304342L}, we proposed a measure called gravitational energy spectrum to quantify the importance of gravity on multiple physical scales. In this…

Solar and Stellar Astrophysics · Physics 2016-10-03 Guang-Xing Li , Andreas Burkert

The role of gravitational instability-driven turbulence in determining the structure and evolution of disk galaxies, and the extent to which gravity rather than feedback can explain galaxy properties, remains an open question. To address…

Astrophysics of Galaxies · Physics 2015-12-02 Nathan J. Goldbaum , Mark R. Krumholz , John C. Forbes

Galactic disks consist of both stars and gas. The gas is more dynamically responsive than the stars, and strongly nonlinear structures and velocities can develop in the ISM even while stellar surface density perturbations remain…

Astrophysics · Physics 2011-02-11 Woong-Tae Kim , Eve C. Ostriker

We aim to better understand how the spatial structure of molecular clouds is governed by turbulence. For that, we study the large-scale spatial distribution of low density molecular gas and search for characteristic length scales. We employ…

Astrophysics of Galaxies · Physics 2015-05-18 N. Schneider , S. Bontemps , R. Simon , V. Ossenkopf , C. Federrath , R. Klessen , F. Motte , P. Andre , J. Stutzki , C. Brunt

The effect of turbulence on snow precipitation is not incorporated into present weather forecasting models. Here we show evidence that turbulence is in fact a key influence on both fall speed and spatial distribution of settling snow. We…

In star-forming clouds, high velocity flow gives rise to large fluctuations of density. In this work we explore the correlation between velocity magnitude (speed) and density. We develop an analytic formula for the joint probability…

Astrophysics of Galaxies · Physics 2023-08-02 Branislav Rabatin , David C. Collins

Turbulent fragmentation determines where and when protostellar cores form, and how they contract and grow in mass from the surrounding cloud material. Molecular cloud regions without turbulent driving sources, or where turbulence is driven…

Astrophysics · Physics 2009-11-06 Ralf Klessen

Hydrodynamical simulations of star formation indicate that the motions of protostars through their natal molecular clouds may be crucial in determining the properties of stars through competitive accretion and dynamical interactions. Walsh,…

Astrophysics · Physics 2008-11-26 Ben A. Ayliffe , James C. Langdon , Howard S. Cohl , Matthew R. Bate

We analyze the gravitational collapse of solids subject to gas drag in a protoplanetary disk. We also study the stirring of solids by turbulent fluctuations to determine the velocity dispersion and thickness of the midplane particle layer.…

Astrophysics · Physics 2007-05-23 Andrew N. Youdin

High spatial and spectral resolution observations of star formation and kinematics in early galaxies have shown that two-thirds are massive rotating disk galaxies with the remainder being less massive non-rotating objects. The line of sight…

We present a numerical study of settling and clustering of small inertial particles in homogeneous and isotropic turbulence. Particles are denser than the fluid, but not in the limit of being much heavier than the displaced fluid. At fixed…

Fluid Dynamics · Physics 2022-01-03 Christian Reartes , Pablo D. Mininni

We have mapped two molecular clouds at (l, b) = (3.2 degrees, + 0.3 degrees) and (l, b) = (5.4 degrees, -0.5 degrees) in 21-cm line and continuum emission. These clouds show unusually large velocity dispersions of more than 100 km/s (FWHM)…

Astrophysics · Physics 2015-06-24 Harald Riffert , Pawan Kumar , W. K. Huchtmeier

We discuss HD and MHD compressible turbulence as a cloud-forming and cloud-structuring mechanism in the ISM. Results from a numerical model of the turbulent ISM at large scales suggest that the phase-like appearance of the medium, the…

Astrophysics · Physics 2007-05-23 Enrique Vazquez-Semadeni , Thierry Passot

The kinetic energy of supersonic turbulence within interstellar clouds is subject to cooling by dissipation in shocks and subsequent line radiation. The clouds are therefore susceptible to a condensation process controlled by the specific…

Astrophysics of Galaxies · Physics 2020-02-05 Eric Keto , George B. Field , Eric G. Blackman

Galaxies' interstellar media (ISM) are observed to be supersonically-turbulent, but the ultimate power source that drives turbulent motion remains uncertain. The two dominant models are that the turbulence is driven by star formation…

Astrophysics of Galaxies · Physics 2016-03-23 Mark R. Krumholz , Blakesley Burkhart

We show that the growth rate of dust grains in cold molecular clouds is enhanced by the high degree of compressibility of a turbulent, dilute gas. By means of high resolution (10243) numerical simulations, we confirm the theory that the…

Astrophysics of Galaxies · Physics 2020-11-18 Xiang-Yu Li , Lars Mattsson