English
Related papers

Related papers: Statistics of Turbulence from Spectral-Line Data C…

200 papers

The interstellar medium (ISM) is ubiquitously turbulent across many physically distinct environments within the Galaxy. Turbulence is key in controlling the structure and dynamics of the ISM, regulating star formation, and transporting…

The role of turbulence in setting boundary plasma conditions is presently a key uncertainty in projecting to fusion energy reactors. To robustly diagnose edge turbulence, we develop and demonstrate a technique to translate brightness…

Reliable nebular emission line diagnostics are essential for accurately inferring the physical properties (e.g. electron temperature, density, pressure, and metallicity) of H II regions from spectra. When interpreting spectra, it is typical…

Astrophysics of Galaxies · Physics 2026-02-06 Larrance Xing , Nicholas Choustikov , Harley Katz , Alex J. Cameron

MHD Turbulence is a critical component of the current paradigms of star formation, particle transport, magnetic reconnection and evolution of the ISM, to name just a few. Progress on this difficult subject is made via numerical simulations…

Astrophysics of Galaxies · Physics 2015-05-27 Blakesley Burkhart , Alex Lazarian

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

We perform three-dimensional (3D) compressible MHD simulations over many dynamical times for an extended range of sonic and Alfven Mach numbers and analyze the statistics of 3D density and 2D column density, which include probability…

Astrophysics · Physics 2009-01-19 G. Kowal , A. Lazarian , A. Beresnyak

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

Turbulent dynamics generate random fluctuations in density and velocity in the Interstellar Medium (ISM) of spiral and dwarf galaxies. Observationally, H~{\sc i} 21-cm radiation provides a good probe of these stochastic processes and helps…

Astrophysics of Galaxies · Physics 2018-05-30 Meera Nandakumar

The investigation of the statistical properties of maps of line centroids has been used for almost 50 years, but there is still no general agreement on their interpretation. We try to quantify which properties of underlying turbulent…

Astrophysics · Physics 2009-11-11 V. Ossenkopf , A. Esquivel , A. Lazarian , J. Stutzki

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

When very small particles are suspended in a fluid in motion, they tend to follow the flow. How such tracer particles are mixed, transported, and dispersed by turbulent flow has been successfully described by statistical models. Heavy…

Fluid Dynamics · Physics 2023-12-21 J. Bec , K. Gustavsson , B. Mehlig

Radio-wave scintillation observations reveal a nearly Kolmogorov spectrum of density fluctuations in the ionized interstellar medium. Although this density spectrum is suggestive of turbulence, no theory relevant to its interpretation…

Astrophysics · Physics 2009-11-06 Yoram Lithwick , Peter Goldreich

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

Quantitative description of the statistics of intensity fluctuations within spectral line data cubes introduced in our earlier work is extended to the absorbing media. A possibility of extracting 3D velocity and density statistics from both…

Astrophysics · Physics 2009-11-10 A. Lazarian , D. Pogosyan

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

In this paper we test the results of a recent analytical study by Lazarian and Pogosyan, on the statistics of emissivity in velocity channel maps, in the case of realistic density and velocity fields obtained from numerical simulations of…

Astrophysics · Physics 2009-11-06 Alex Lazarian , Dmitri Pogosyan , Enrique Vazquez-Semadeni , Barbara Pichardo

Identification and extraction of vortical structures and of waves in a disorganised flow is a mayor challenge in the study of turbulence. We present a study of the spatio-temporal behavior of turbulent flows in the presence of different…

Fluid Dynamics · Physics 2015-11-09 P. Clark di Leoni , P. J. Cobelli , P. D. Mininni

The transport of charged energetic particles in the presence of strong intermittent heliospheric turbulence is computationally analyzed based on known properties of the interplanetary magnetic field and solar wind plasma at 1 Astronomical…

High Energy Astrophysical Phenomena · Physics 2015-06-18 Fathallah Alouani-Bibi , Jakobus A. le Roux

Magnetic field fluctuations measured in the heliosheath by the Voyager spacecraft are often characterized as compressible, as indicated by a strong fluctuating component parallel to the mean magnetic field. However, the interpretation of…

Space Physics · Physics 2024-08-01 L. -L. Zhao , G. P. Zank , M. Opher , B. Zieger , H. Li , V. Florinski , L. Adhikari , X. Zhu , M. Nakanotani

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