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Related papers: Density Probability Distribution Functions in Supe…

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We conduct numerical experiments to determine the density probability distribution function (PDF) produced in supersonic, isothermal, self-gravitating turbulence of the sort that is ubiquitous in star-forming molecular clouds. Our…

Astrophysics of Galaxies · Physics 2021-08-10 Shivan Khullar , Christoph Federrath , Mark R. Krumholz , Christopher D. Matzner

We study density fluctuations in supersonic turbulence using both theoretical methods and numerical simulations. A theoretical formulation is developed for the probability distribution function (PDF) of the density at steady state,…

Astrophysics of Galaxies · Physics 2019-09-04 Liubin Pan , Paolo Padoan , Åke Nordlund

The shape of the probability distribution function (PDF) of molecular clouds is an important ingredient for modern theories of star formation and turbulence. Recently, several studies have pointed out observational difficulties with…

Astrophysics of Galaxies · Physics 2015-10-07 Blakesley Burkhart , Min-Young Lee , Claire Murray , Snezana Stanimirovic

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

The probability density function (PDF) of the logarithmic density contrast, $s=\ln (\rho/\rho_0)$, with gas density $\rho$ and mean density $\rho_0$, for hydrodynamical supersonic turbulence is well-known to have significant non-Gaussian…

Astrophysics of Galaxies · Physics 2022-11-16 James R. Beattie , Philip Mocz , Christoph Federrath , Ralf S. Klessen

Compressive isothermal turbulence is known to have a near lognormal density probability distribution function (PDF) with a width that scales with the sonic Mach number and nature of the turbulent driving (solenoidal vs compressive).…

Astrophysics of Galaxies · Physics 2019-11-06 Philip Mocz , Blakesley Burkhart

In star-forming clouds, high velocity flow gives rise to large fluctuations of density. In this work we explore the correlation between velocity magnitude (speed) and density. We develop an analytic formula for the joint probability…

Astrophysics of Galaxies · Physics 2023-08-02 Branislav Rabatin , David C. Collins

We numerically study the volume density probability distribution function (n-PDF) and the column density probability distribution function (Sigma-PDF) resulting from thermally bistable turbulent flows. We analyze three-dimensional…

Astrophysics of Galaxies · Physics 2015-06-12 Adriana Gazol , Jongsoo Kim

Turbulence is essential for understanding the structure and dynamics of molecular clouds and star-forming regions. There is a need for adequate tools to describe and characterize the properties of turbulent flows. One-point probability…

Astrophysics · Physics 2008-11-26 Ralf S. Klessen

In an effort to characterize the Mach numbers of ISM magnetohydrodynamic (MHD) turbulence, we study the probability distribution functions (PDFs) of patial increments of density, velocity, and magnetic field for fourteen ideal isothermal…

Astrophysics of Galaxies · Physics 2015-05-27 Benjamin M. Tofflemire , Blakesley Burkhart , A. Lazarian

The probability density function (PDF) of the gas density in subsonic and supersonic, isothermal, driven turbulence is analyzed with a systematic set of hydrodynamical grid simulations with resolutions up to 1024^3 cells. We performed a…

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

The question of the shape of the density PDF for supersonic turbulence is addressed, using both analytical and numerical methods. For isothermal supersonic turbulence, the PDF is Log-Normal, with a width that scales approximately linearly…

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

The probability distribution function (PDF) of the mass surface density of molecular clouds provides essential information about the structure of molecular cloud gas and condensed structures out of which stars may form. In general, the PDF…

Astrophysics of Galaxies · Physics 2015-06-22 Jörg Fischera

We investigate the behavior of the magnetic pressure, $b^2$, in fully turbulent MHD flows in ``1+2/3'' dimensions by means of its effect on the probability density function (PDF) of the density field. We start by reviewing our previous…

Astrophysics · Physics 2007-05-23 Enrique Vazquez-Semadeni , Thierry Passot

We study the effects of radiative transfer on the Probability Distribution Functions (PDFs) of simulations of magnetohydrodynamic turbulence in the widely studied $^{13}$CO 2-1 transition. We find that the integrated intensity maps…

Astrophysics of Galaxies · Physics 2015-06-15 Blakesley Burkhart , V. Ossenkopf , A. Lazarian , J. Stutzki

Using a suite of 3D hydrodynamical simulations of star-forming molecular clouds, we investigate how the density probability distribution function (PDF) changes when including gravity, turbulence, magnetic fields, and protostellar outflows…

Astrophysics of Galaxies · Physics 2022-03-14 Sabrina M. Appel , Blakesley Burkhart , Vadim A. Semenov , Christoph Federrath , Anna L. Rosen

We study the observable signatures of self-gravitating MHD turbulence by applying the probability density functions (PDFs) and the spatial density power spectrum to synthetic column density maps. We find that there exists three…

Solar and Stellar Astrophysics · Physics 2015-08-06 Blakesley Burkhart , David C. Collins , Alex Lazarian

The probability distribution function (PDF) of the mass surface density is an essential characteristic of the structure of molecular clouds or the interstellar medium in general. Observations of the PDF of molecular clouds indicate a…

Astrophysics of Galaxies · Physics 2015-06-18 Joerg Fischera

There has been overwhelming evidence that coherent structures play a critical role in determining the overall transport in a variety of systems. We compute the probability distribution function (PDF) tails of momentum flux and heat flux in…

Plasma Physics · Physics 2009-11-13 Johan Anderson , Eun-jin Kim

We propose a new, physically motivated fitting function for density PDFs in turbulent gas. Although it is known that when gas is isothermal, the PDF is approximately lognormal in the core, high-resolution simulations show large deviations…

Astrophysics of Galaxies · Physics 2013-07-02 Philip F. Hopkins
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