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Related papers: Quest for HI Turbulence Statistics: New Techniques

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This report proposes a new method to study vortex tubes in one-dimensional velocity data of experimental turbulence. Vortex tubes are detected as local maxima on the scale-space plot of wavelet transforms of the velocity data. Then it is…

Fluid Dynamics · Physics 2009-11-07 H. Mouri , M. Takaoka

Statistical tools are crucial for studying and modeling turbulent flows, where chaotic velocity fluctuations span a wide range of spatial and temporal scales. Advances in image velocimetry, especially in tracking-based methods, now allow…

Fluid Dynamics · Physics 2025-02-19 Miguel A. Mendez , Manuel Ratz , Damien Rigutto

We present an analytical study of the statistical properties of integrated emission and velocity centroids for a slightly compressible turbulent slab model, to retrieve the underlying statistics of three-dimensional density and velocity…

Astrophysics · Physics 2009-11-10 F. Levrier

We examine a model for the variable free-free and neutral hydrogen absorption inferred towards the cores of some compact radio galaxies in which a spatially fluctuating medium drifts in front of the source. We relate the absorption-induced…

Astrophysics of Galaxies · Physics 2016-07-27 Jean-Pierre Macquart , Steven Tingay

We propose and validate a novel experimental technique to measure two-point statistics of turbulent flows. It consists in spreading rigid fibers in the flow and tracking their position and orientation in time and therefore been named…

We expand on the dispersion analysis of polarimetry maps toward applications to interferometry data. We show how the filtering of low-spatial frequencies can be accounted for within the idealized Gaussian turbulence model, initially…

Astrophysics of Galaxies · Physics 2016-03-23 Martin Houde , Charles L. H. Hull , Richard L. Plambeck , John E. Vaillancourt , Roger H. Hildebrand

Turbulence is ubiquitous in the insterstellar medium and plays a major role in several processes such as the formation of dense structures and stars, the stability of molecular clouds, the amplification of magnetic fields, and the…

Astrophysics of Galaxies · Physics 2015-06-19 D. Falceta-Goncalves , G. Kowal , E. Falgarone , A. C. -L. Chian

We utilize the multi-wavelength data of M33 to study the origin of turbulence in its interstellar medium. We find that the HI turbulent energy surface density inside 8 kpc is $\sim1-3~\times~10^{46}$ erg pc$^{-2}$, and has no strong…

Astrophysics of Galaxies · Physics 2019-01-23 Dyas Utomo , Leo Blitz , Edith Falgarone

Roles of turbulence in the context of magnetic reconnection are investigated with special emphasis on the mutual interaction between flow (large-scale inhomogeneous structure) and turbulence. In order to evaluate the effective transport due…

Solar and Stellar Astrophysics · Physics 2015-05-28 Nobumitsu Yokoi , Masahiro Hoshino

All molecular clouds are observed to be turbulent, but the origin, means of sustenance, and evolution of the turbulence remain debated. One possibility is that stellar feedback injects enough energy into the cloud to drive observed motions…

Astrophysics of Galaxies · Physics 2016-12-28 Ryan D. Boyden , Eric W. Koch , Erik W. Rosolowsky , Stella S. R. Offner

Gravitational and hydrodynamical perturbations are analysed in a relativistic plasma containing a mixture of interacting fluids characterized by a non-negligible bulk viscosity coefficient. The energy-momentum transfer between the…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Massimo Giovannini

The understanding of inertial-scale dynamics in the heliosheath is not yet thorough. Magnetic field fluctuations across the inner heliosheath (IHS) and the local interstellar medium (LISM) are here considered to provide accurate and highly…

Vortical structures of turbulence, i.e., vortex tubes and sheets, are studied using one-dimensional velocity data obtained in laboratory experiments for duct flows and boundary layers at microscale Reynolds numbers from 332 to 1934. We…

Fluid Dynamics · Physics 2009-11-13 H. Mouri , A. Hori , Y. Kawashima

Plasma turbulence is studied via direct numerical simulations in a two-dimensional spatial geometry. Using a hybrid Vlasov-Maxwell model, we investigate the possibility of a velocity-space cascade. A novel theory of space plasma turbulence…

Plasma Physics · Physics 2018-08-01 O. Pezzi , S. Servidio , D. Perrone , F. Valentini , L. Sorriso-Valvo , A. Greco , W. H. Matthaeus , P. Veltri

We have in earlier work (Basse N P 2005, Phys. Lett. A vol. 340 p. 456) reported on intriguing similarities between density fluctuation power versus wavenumber on small (mm) and large (Mpc) scales. In this paper we expand upon our previous…

Plasma Physics · Physics 2007-05-23 N P Basse

We analyze hydrodynamic simulations of turbulent, star-forming molecular clouds that are post-processed with the photo-dissociation region astrochemistry code 3D-PDR. We investigate the sensitivity of 15 commonly applied turbulence…

Astrophysics of Galaxies · Physics 2018-07-11 Ryan D. Boyden , Stella S. R. Offner , Eric W. Koch , Erik W. Rosolowsky

The velocity fluctuations for point vortex models are studied for the {\alpha}-turbulence equations, which are characterized by a fractional Laplacian relation between active scalar and the streamfunction. In particular, we focus on the…

Fluid Dynamics · Physics 2019-09-11 Giovanni Conti , Gualtiero Badin

We present synthetic Hi and CO observations of a simulation of decaying turbulence in the thermally bistable neutral medium. We first present the simulation, with clouds initially consisting of clustered clumps. Self-gravity causes these…

Astrophysics of Galaxies · Physics 2015-08-06 Jonathan S. Heiner , Enrique Vázquez-Semadeni , Javier Ballesteros-Paredes

An analytical formula for the probability density function (PDF) of the velocity fluctuation in fully-developed turbulence is derived, non-perturbatively, by assuming that its underlying statistics is the one based on the generalized…

Statistical Mechanics · Physics 2015-06-24 Toshihico Arimitsu , Naoko Arimitsu

Grid turbulence is investigated using cross-correlation digital Particle Image Velocimetry (PIV) over a range of Taylor Reynolds Number (Re{\lambda}) from 5 to 44. Instantaneous velocity is measured directly and vorticity and velocity…

Fluid Dynamics · Physics 2021-03-16 Philippa O'Neill , David Nicolaides , Damon Honnery , Julio Soria