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Light propagation in turbulent media is conventionally studied with the help of the spatio-temporal power spectra of the refractive index fluctuations. In particular, for natural water turbulence several models for the spatial power spectra…

Atmospheric and Oceanic Physics · Physics 2021-01-28 Jinren Yao , Hantao Wang , Huajun Zhang , Jiandong Cai , Mingyuan Ren , Yu Zhang , Olga Korotkova

We study how the estimation of the sonic Mach number ($M_s$) from $^{13}$CO linewidths relates to the actual 3D sonic Mach number. For this purpose we analyze MHD simulations which include post-processing to take radiative transfer effects…

Supersonic turbulence is a large reservoir of suprathermal energy in the interstellar medium. Its dissipation, because it is intermittent in space and time, can deeply modify the chemistry of the gas. We further explore a hybrid method to…

Astrophysics of Galaxies · Physics 2009-11-13 Benjamin Godard , Edith Falgarone , Guillaume Pineau Des Forêts

Turbulence is a dominant feature operating in gaseous flows across nearly all scales in astrophysical environments. Accordingly, accurately estimating the statistical properties of such flows is necessary for developing a comprehensive…

Solar and Stellar Astrophysics · Physics 2014-11-27 Lukas Konstandin , Rahul Shetty , Philipp Girichidis , Ralf S. Klessen

Fourier transform power spectra of azimuthal scans of the optical structure of M33 are evaluated for B, V, and R passbands and fit to fractal models of continuum emission with superposed star formation. Power spectra are also determined for…

We develop a visibility based power spectrum estimator to probe the power spectrum directly from the interferometric observations and also estimate the errors in it. A numerical simulation of synthetic observations is also performed to…

Astrophysics of Galaxies · Physics 2011-02-23 Prasun Dutta

We present a number of statistical tools for obtaining studying turbulence in molecular clouds and diffuse interstellar medium. For our tests we used of three-dimensional 512 cube compressible MHD isothermal simulations performed for…

Astrophysics · Physics 2011-02-11 Blakesley Burkhart , D. Falceta-Goncalves , G. Kowal , A. Lazarian

[abridged] The interstellar medium is now widely recognized to display features ascribable to magnetized turbulence. With the public release of Planck data and the current balloon-borne and ground-based experiments, the growing amount of…

Astrophysics of Galaxies · Physics 2018-06-27 F. Levrier , J. Neveu , E. Falgarone , F. Boulanger , A. Bracco , T. Ghosh , F. Vansyngel

The turbulence of capillary waves on the surface of a ferrofluid with a high permeability in a horizontal magnetic field is considered in the framework of a one-dimensional weakly nonlinear model. In the limit of a strong magnetic field,…

Fluid Dynamics · Physics 2020-02-21 Evgeny A. Kochurin

Ambipolar diffusion (AD) is believed to be a crucial process for redistributing magnetic flux in the dense molecular gas that occurs in regions of star formation. We carry out numerical simulations of this process in regions of low…

Solar and Stellar Astrophysics · Physics 2015-05-30 Pak Shing Li , Christopher F. McKee , Richard I. Klein

We investigate the scale dependence of fluctuations inside a realistic model of an evolving turbulent HII region and to what extent these may be studied observationally. We find that the multiple scales of energy injection from champagne…

Astrophysics of Galaxies · Physics 2015-06-22 S. -N. X. Medina , S. J. Arthur , W. J. Henney , G. Mellema , A. Gazol

Theoretical considerations are made of superfluid turbulence in the Kelvin wave cascade regime at low temperatures (T < 1K) and length scales of the order or smaller than the intervortical distance. The energy spectrum is shown to be in…

Other Condensed Matter · Physics 2017-12-07 Bhimsen Shivamoggi

Observations indicate that the central gas discs are smoother in early-type galaxies than their late-type counterparts, while recent simulations predict that the dynamical suppression of star formation in spheroid-dominated galaxies is…

MHD turbulence driven at velocities higher than the Alfv\'en velocity, i.e., super-Alfv\'enic turbulence, is widely spread in astrophysical environments, including galaxy clusters and molecular clouds. For statistical studies of such…

Astrophysics of Galaxies · Physics 2025-11-13 A. Lazarian , D. Pogosyan , Y. Hu

Supersonic turbulence fragments the interstellar medium into dense sheets, filaments, cores and large low density voids. The turbulence is driven on large scales, probably predominantly by supernovae. The scaling properties of supersonic…

Astrophysics · Physics 2007-05-23 Aake Nordlund , Paolo Padoan

Turbulence is ubiquitous in astrophysical fluids such as the interstellar medium (ISM) and the intracluster medium (ICM). In turbulence studies, it is customary to assume that fluid is driven on a single scale. However, in astrophysical…

Astrophysics of Galaxies · Physics 2015-06-18 Hyunju Yoo , Jungyeon Cho

Based on fractional Brownian motion (fBm) simulations of 3D gas density and velocity fields, we present a study of the statistical properties of spectro-imagery observations (channel maps, integrated emission, and line centroid velocity) in…

Astrophysics · Physics 2009-11-07 M. -A. Miville-Deschenes , F. Levrier , E. Falgarone

The strengths of magnetic fields in interstellar gas clouds are obtained through observations of the circular polarization of spectral line radiation. Irregularities in this magnetic field may be present due to turbulence, waves or perhaps…

Astrophysics · Physics 2009-10-31 W. D. Watson , D. S. Wiebe , R. M. Crutcher

Observations of interstellar scintillations at radio wavelengths reveal a Kolmogorov-like scaling of the electron density spectrum with a spectral slope of -5/3 over six decades in wavenumber space. A similar turbulent density spectrum in…

Space Physics · Physics 2015-05-13 Dastgeer Shaikh , G. P. Zank

Magnetohydrodynamic turbulence is a ubiquitous phenomenon in solar physics, plasma physics and astrophysics and governs many properties of the flows of well-conductive fluids. Recently, conflicting spectral slopes for the inertial range of…

Astrophysics of Galaxies · Physics 2015-06-18 Andrey Beresnyak