Browsing by Keyword "turbulence"
Now showing items 1-14 of 14
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Anchoring Magnetic Fields in Turbulent Molecular Clouds
(American Astronomical Society, 2009)One of the key problems in star formation research is to determine the role of magnetic fields. Starting from the atomic intercloud medium which has density \(n_H \sim \ 1 \ cm^{–3}\), gas must accumulate from a volume ... -
The Angular Momentum of Magnetized Molecular Cloud Cores: A Two-Dimensional-Three-Dimensional Comparison
(Institute of Physics Publishing, Inc., 2010)In this work, we present a detailed study of the rotational properties of magnetized and self-gravitating dense molecular cloud cores formed in a set of two very high resolution three-dimensional molecular cloud simulations ... -
Angular Momentum Transport in Convectively Unstable Shear Flows
(IOP Publishing, 2010)Angular momentum transport due to hydrodynamic turbulent convection is studied using local three-dimensional numerical simulations employing the shearing box approximation. We determine the turbulent viscosity from nonrotating ... -
The Complete Survey of Outflows in Perseus
(American Astronomical Society, 2010)We present a study on the impact of molecular outflows in the Perseus molecular cloud complex using the COMPLETE Survey large-scale \(^{12}CO(1-0)\) and \(^{13}CO(1-0)\) maps. We used three-dimensional isosurface models ... -
The Dynamics of Dense Cores in the Perseus Molecular Cloud II: the Relationship between Dense Cores and the Cloud
(Institute of Physics Publishing, Inc., 2010)We utilize the extensive datasets available for the Perseus molecular cloud to analyze the relationship between the kinematics of small-scale dense cores and the larger structures in which they are embedded. The kinematic ... -
Extreme Brightness Temperatures and Refractive Substructure in 3C 273 with RadioAstron
(American Astronomical Society, 2016)Earth–space interferometry with RadioAstron provides the highest direct angular resolution ever achieved in astronomy at any wavelength. RadioAstron detections of the classic quasar 3C 273 on interferometric baselines up ... -
Fisher Equation with Turbulence in One Dimension
(Elsevier, 2009)As an example of life at high Reynolds number, we investigate the dynamics of the Fisher equation for the spreading of micro-organisms in one dimension subject to both turbulent convection and diffusion. We show that for ... -
From Rings to Smoke: the quest to uncover a mechanism of turbulence
(2021-04-01)The equations of motion that govern the dynamics of fluid flows--the Navier-Stokes equations--were formulated nearly two centuries ago. In that time, we have made immense advancements in the ways that we understand these ... -
H2 excitation in turbulent interstellar clouds
(Oxford University Press (OUP), 2005)We discuss the observational differences between lines of sight that intercept a group of turbulent dissipative structures and lines of sight that cross less-active regions. Using time-dependent calculations we show that ... -
H2O Masers and Supersonic Turbulence
(IOP Publishing, 2002)We use unpublished and published VLBI results to investigate the geometry and the statistical properties of the velocity field traced by H2O masers in five galactic regions of star formation — Sgr B2(M), W49N, W51(MAIN), ... -
Hierarchical Structure of Magnetohydrodynamic Turbulence in Position-Position-Velocity Space
(American Astronomical Society, 2013)Magnetohydrodynamic turbulence is able to create hierarchical structures in the interstellar medium (ISM) that are correlated on a wide range of scales via the energy cascade. We use hierarchical tree diagrams known as ... -
Thermal stability in turbulent accretion discs
(Oxford University Press (OUP), 2013)The standard thin accretion disc model predicts that discs around stellar mass black holes become radiation pressure dominated and thermally unstable once their luminosity exceeds L & 0.02LEdd. Observationally, discs in ... -
Turbulence and Star Formation Efficiency in Molecular Clouds: Solenoidal Versus Compressive Motions in Orion B
(EDP Sciences, 2017-03)Context: The nature of turbulence in molecular clouds is one of the key parameters that control star formation efficiency: compressive motions, as opposed to solenoidal motions, can trigger the collapse of cores, or mark ... -
Turbulent-diffusion Mediated CO Depletion in Weakly Turbulent Protoplanetary Disks
(American Astronomical Society, 2017)Volatiles, especially CO, are important gas tracers of protoplanetary disks (PPDs). Freeze-out and sublimation processes determine their division between gas and solid phases, which affects both which disk regions can be ...