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Related papers: Turbulence in Atomic Hydrogen

200 papers

A program is outlined, and first results described, in which fully three-dimensional, time dependent simulations of hydrodynamic turbulence are used as a basis for theoretical investigation of the physics of turbulence in stars. The…

Solar and Stellar Astrophysics · Physics 2015-05-14 W. David Arnett , Casey Meakin

We present a numerical and analytical study of the thermal fragmentation of a turbulent flow of interstellar hydrogen. We first present the different dynamical processes and the large range of spatial (and temporal) scales that need to be…

Astrophysics · Physics 2009-11-10 E. Audit , P. Hennebelle

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

Understanding the timescales of atomic gas turbulence is crucial to understanding the interplay between star formation and the interstellar medium (ISM). To investigate the timescales of turbulence low-mass galaxies…

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

We introduce and test an expression for calculating the variance of a physical field in three dimensions using only information contained in the two-dimensional projection of the field. The method is general but assumes statistical…

Astrophysics of Galaxies · Physics 2015-05-14 C. M. Brunt , C. Federrath , D. J. Price

Theoretical approaches to low-frequency magnetized turbulence in collisionless and weakly collisional astrophysical plasmas are reviewed. The proper starting point for an analytical description of these plasmas is kinetic theory, not fluid…

Astrophysics · Physics 2009-11-11 A. A. Schekochihin , S. C. Cowley , W. Dorland

Magnetohydrodynamic (MHD) turbulence plays a critical role in many key astrophysical processes such as star formation, acceleration of cosmic rays, and heat conduction. However, its properties are still poorly understood. We explore how to…

High Energy Astrophysical Phenomena · Physics 2024-10-30 Ru-Yue Wang , Jian-Fu Zhang , Fang Lu , Fu-Yuan Xiang

Turbulence in curved spacetimes in general, and in the vicinity of black holes (BHs) in particular, represents a poorly understood phenomenon that is often analysed employing techniques developed for flat spacetimes. We here propose a novel…

General Relativity and Quantum Cosmology · Physics 2025-11-19 Rita Megale , Alejandro Cruz-Osorio , Giuseppe Ficarra , Mario Imbrogno , Claudio Meringolo , Leonardo Primavera , Luciano Rezzolla , Sergio Servidio

The 21-cm emission from atomic hydrogen (HI) is one of the most important tracers of the structure and dynamics of the interstellar medium. Thanks to Galactic rotation, the line is Doppler shifted and, assuming a model for the velocity…

Astrophysics of Galaxies · Physics 2023-05-26 Philipp Mertsch , Vo Hong Minh Phan

Turbulence is a key element of the dynamics of astrophysical fluids, including those of interstellar medium, clusters of galaxies and circumstellar regions. Turbulent motions induce Doppler shifts of observable emission and absorption lines…

Astrophysics · Physics 2009-03-27 A. Chepurnov , A. Lazarian

Small-scale fluctuations of different tracers of the interstellar the medium can be used to study the nature of turbulence in astrophysical scales. Of these, the `continuum' emission traces the fluctuations integrated along the line of…

Astrophysics of Galaxies · Physics 2019-01-30 Samir Choudhuri , Nirupam Roy

X-ray observations of the hot gas filling the intra-cluster medium provide a wealth of information on the dynamics of clusters of galaxies. The global equilibrium of the ICM is believed to be partially ensured by non-thermal pressure…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-25 E. Cucchetti , N. Clerc , E. Pointecouteau , P. Peille , F. Pajot

Intermittency is an essential property of astrophysical fluids, which demonstrate an extended inertial range. As intermittency violates self-similarity of motions, it gets impossible to naively extrapolate the properties of fluid obtained…

Astrophysics · Physics 2011-05-10 A. Lazarian

We present a direct numerical and analytical study of driven supersonic MHD turbulence that is believed to govern the dynamics of star-forming molecular clouds. We describe statistical properties of the turbulence by measuring the velocity…

Astrophysics · Physics 2009-11-07 Stanislav Boldyrev , Aake Nordlund , Paolo Padoan

In this presentation we review the link between the statistics of intensity fluctuations in spectral line data cubes with underlying statistical properties of turbulence in the interstellar medium. Both the formalism of Velocity Channel…

Astrophysics · Physics 2009-11-11 Dmitri Pogosyan , Alex Lazarian

This two-part review summarizes interstellar turbulence and its implications. The first part begins with diagnostics and energy sources. Turbulence theory is considered in detail, including the basic fluid equations, solenoidal and…

Astrophysics · Physics 2008-11-26 Bruce G. Elmegreen , John Scalo

Broadening and asymmetry of spectral lines in slowly rotating late A-type stars provide evidence for high-amplitude convective motions. The properties of turbulence observed in the A-star atmospheres are not understood theoretically and…

Astrophysics · Physics 2015-06-24 O. Kochukhov , B. Freytag , N. Piskunov , M. Steffen

We assemble a homogeneous database of precise and consistent determinations of effective temperature, surface gravity, projected rotational rate, and macro- and micro-turbulent velocities for over 1800 Galactic stars spanning spectral types…

Solar and Stellar Astrophysics · Physics 2025-10-01 N. Markova , M. Cantiello , L. Grassitelli

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