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Related papers: Turbulent Velocity Structure in Molecular Clouds

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We present a wide-field $(60\arcmin \times 30\arcmin)$ study of a dense region within the Polaris Flare, hereafter referred to as the `Polaris molecular cloud', using $^{12}$CO, $^{13}$CO, and C$^{18}$O ($J=1-0$) observations at $20\arcsec$…

Astrophysics of Galaxies · Physics 2025-02-18 Tomomi Shimoikura , Kazuhito Dobashi , Fumitaka Nakamura , Kotomi Taniguchi

Recent advances in understanding of the basic properties of compressible Magnetohydrodynamic (MHD) turbulence call for revisions of some of the generally accepted concepts. First, MHD turbulence is not so messy as it is usually believed. In…

Astrophysics · Physics 2009-11-10 A. Lazarian , J. Cho

Turbulence dissipation is an important process affecting the energy balance in molecular clouds, the birth place of stars. Previously, the rate of turbulence dissipation is often estimated with semi-analytic formulae from simulation.…

Instrumentation and Methods for Astrophysics · Physics 2018-10-10 Lei Qian , Di Li , Yang Gao , Haitao Xu , Zhichen Pan

We analyze the spectral properties of driven, supersonic compressible magnetohydrodynamic (MHD) turbulence obtained via high-resolution numerical experiments, for application to understanding the dynamics of giant molecular clouds. Via…

Astrophysics · Physics 2009-11-07 Jason G. Vestuto , Eve C. Ostriker , James M. Stone

The interaction of turbulence, magnetic fields, self-gravity, and stellar feedback within molecular clouds is crucial for understanding star formation. We study the effects of self-gravity and outflow feedback on the properties of the…

Astrophysics of Galaxies · Physics 2022-04-25 Yue Hu , Christoph Federrath , Siyao Xu , Sajay Sunny Mathew

The probability density function (PDF) of velocity fluctuations is studied experimentally for grid turbulence in a systematical manner. At small distances from the grid, where the turbulence is still developing, the PDF is sub-Gaussian. At…

Fluid Dynamics · Physics 2009-11-07 H. Mouri , M. Takaoka , A. Hori , Y. Kawashima

Turbulence is a crucial component of dynamics of astrophysical fluids dynamics, including those of ISM, clusters of galaxies and circumstellar regions. Doppler shifted spectral lines provide a unique source of information on turbulent…

Astrophysics · Physics 2007-05-23 A. Lazarian

We present a comprehensive study of MHD waves and instabilities in a weakly ionised system, e.g., an interstellar molecular cloud. We determine all the critical wavelengths of perturbations across which the sustainable wave modes can change…

Solar and Stellar Astrophysics · Physics 2011-04-01 Telemachos Ch. Mouschovias , Glenn E. Ciolek , S. A. Morton

We used magnetohydrodynamic (MHD) simulations of interstellar turbulence to study the probability distribution functions (PDFs) of increments of density, velocity, and magnetic field. We found that the PDFs are well described by a Tsallis…

Astrophysics of Galaxies · Physics 2011-08-04 A. Esquivel , A. Lazarian

Despite the simplicity of theoretical models of supersonically turbulent, isothermal media, their predictions successfully match the observed gas structure and star formation activity within low-pressure (P/k < 10^5 K cm^-3) molecular…

The rotational properties of centrally condensed, turbulent molecular cloud cores with velocity fields that are characterized by Gaussian random fields are investigated. It is shown that the observed line width-size relationship can be…

Astrophysics · Physics 2009-10-31 Andreas Burkert , Peter Bodenheimer

We present the Multiscale non-Gaussian Segmentation (MnGSeg) analysis technique. This wavelet based method combines the analysis of the probability distribution function (PDF) of map fluctuations as a function of spatial scales and the…

Astrophysics of Galaxies · Physics 2019-08-07 J. -F. Robitaille , F. Motte , N. Schneider , D. Elia , S. Bontemps

We have investigated the degree to which turbulence in the Very Local Interstellar Clouds resembles the highly-studied turbulence in the solar corona and the solar wind. The turbulence diagnostics for the Local Clouds are the absorption…

Astrophysics of Galaxies · Physics 2015-05-28 Steven R. Spangler , Allison H. Savage , Seth Redfield

The analytical formalism to obtain the probability distribution functions (PDFs) of spherically-averaged cosmic densities and velocity divergences in the mildly non-linear regime is presented. A large-deviation principle is applied to those…

Cosmology and Nongalactic Astrophysics · Physics 2017-08-03 Cora Uhlemann , Sandrine Codis , Oliver Hahn , Christophe Pichon , Francis Bernardeau

Feedback from protostellar outflows can influence the nature of turbulence in star forming regions even if they are not the primary source of velocity dispersion for all scales of molecular clouds. For the rate and power expected in star…

Solar and Stellar Astrophysics · Physics 2015-05-18 Jonathan J. Carroll , Adam Frank , Eric G Blackman

Turbulent flows beneath a free surface play a central role in the Earth system, yet their coupling to observable surface features remains incompletely understood. Recent studies using Direct Numerical Simulations (DNS) have reported strong…

Velocity anisotropy induced by MHD turbulence is investigated using computational simulations and molecular line observations of the Taurus molecular cloud. A new analysis method is presented to evaluate the degree and angle of velocity…

Astrophysics · Physics 2009-11-13 Mark Heyer , Hao Gong , Eve Ostriker , Christopher Brunt

Radial velocity fluctuations on the plane of the sky are a powerful tool for studying the turbulent dynamics of emission line regions. We conduct a systematic statistical analysis of the H alpha velocity field for a diverse sample of 9 H II…

Astrophysics of Galaxies · Physics 2023-06-14 J. García-Vázquez , William J. Henney , H. O. Castañeda

The Very Local Interstellar Medium (VLISM) contains clouds which consist of partially-ionized plasma. These clouds can be effectively diagnosed via high resolution optical and ultraviolet spectroscopy of the absorption lines they form in…

Astrophysics of Galaxies · Physics 2015-05-19 Steven R. Spangler , Allison H. Savage , Seth Redfield

We analyze high resolution simulations of compressible, MHD turbulence with properties resembling conditions in galaxy clusters. The flow is driven to turbulence Mach number $\mathcal{M}_t \sim 1/2$ in an isothermal medium with an initially…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-16 David H. Porter , T. W. Jones , Dongsu Ryu
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