English
Related papers

Related papers: The density variance -- Mach number relation in su…

200 papers

We study the statistics of density for supersonic turbulence in a medium with magnetic pressure larger than the gaseous pressure. This study is motivated by molecular cloud research. Our simulations exhibit clumpy density structures, which…

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

The probability distribution of density in isothermal, supersonic, turbulent gas is approximately lognormal. This behaviour can be traced back to the shock waves travelling through the medium, which randomly adjust the density by a random…

Astrophysics of Galaxies · Physics 2022-10-20 Branislav Rabatin , David C. Collins

The power spectrum (PS) of the density field in supersonic turbulence is a fundamental quantity that characterizes the statistical properties of the structures formed in compressible flows. It is also widely used to estimate the Mach number…

Astrophysics of Galaxies · Physics 2026-05-12 Pierre Dumond , Jérémy Fensch , Gilles Chabrier , Noé Brucy

The compressibility of molecular cloud (MC) turbulence plays a crucial role in star formation models, because it controls the amplitude and distribution of density fluctuations. The relation between the compressive ratio (the ratio of…

Astrophysics of Galaxies · Physics 2016-07-06 Liubin Pan , Paolo Padoan , Troels Haugbolle , Aake Nordlund

Understanding the role of turbulence in shaping the interstellar medium (ISM) is crucial for studying star formation, molecular cloud evolution, and cosmic ray propagation. Central to this is the measurement of the sonic Mach number…

Astrophysics of Galaxies · Physics 2025-02-06 Tyler Schmaltz , Yue Hu , Alex Lazarian

In many astrophysical environments, mixing of heavy elements occurs in the presence of a supersonic turbulent velocity field. Here we carry out the first systematic numerical study of such passive scalar mixing in isothermal supersonic…

Astrophysics of Galaxies · Physics 2015-05-19 Liubin Pan , Evan Scannapieco

We study the probability distribution function (PDF) of the mass density in simulations of supersonic turbulence with properties appropriate for molecular clouds. For this study we use Athena, a new higher-order Godunov code. We find there…

Astrophysics · Physics 2008-09-23 M. Nicole Lemaster , James M. Stone

The interstellar medium of galaxies is governed by supersonic turbulence, which likely controls the star formation rate (SFR) and the initial mass function (IMF). Interstellar turbulence is non-universal, with a wide range of Mach numbers,…

Astrophysics of Galaxies · Physics 2015-03-13 Christoph Federrath , Supratik Banerjee

The Variable Density and Speed of Sound Vessel (VDSSV) produces subsonic turbulent flows that are both compressible and observable at all scales with existing instrumentation including hot wires and particle tracking. We realize this…

Fluid Dynamics · Physics 2022-02-23 N. Manzano-Miura , D. Gloutak , G. P. Bewley

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

Fractional Brownian motion (fBm) structures are used to investigate the dependency of column density variance ({\sigma}_{\ln N}^2) in the turbulent interstellar medium on the variance of three-dimensional density ({\sigma}_{\ln\rho}^2) and…

Astrophysics of Galaxies · Physics 2015-06-12 Kwang-Il Seon

Understanding the physics of turbulence is crucial for many applications, including weather, industry, and astrophysics. In the interstellar medium (ISM), supersonic turbulence plays a crucial role in controlling the gas density and…

Astrophysics of Galaxies · Physics 2021-01-15 Christoph Federrath , Ralf S. Klessen , Luigi Iapichino , James R. Beattie

Wu et al. (2009) suggested an empirical relation between the magnetic field strength along the line of sight (LOS) and the dispersion of Faraday rotation measure (RM) distribution in turbulent media with root-mean-square sonic Mach number…

Astrophysics of Galaxies · Physics 2014-03-03 Qingwen Wu , Jongsoo Kim , Dongsu Ryu

We revisit the relation between the variance of three-dimensional (3D) density ($\sigma^{2}_{\rho}$) and that of the projected two-dimensional (2D) column density ($\sigma^{2}_{\Sigma}$) in turbulent media, which is of great importance in…

Astrophysics of Galaxies · Physics 2024-06-26 Heesun Yoon , Jungyeon Cho

Coagulation driven by supersonic turbulence is primarily an astrophysical problem because coagulation processes on Earth are normally associated with incompressible fluid flows at low Mach numbers, while dust aggregation in the interstellar…

Fluid Dynamics · Physics 2021-04-30 Xiang-Yu Li , Lars Mattsson

Colliding hypersonic flows play a decisive role in many astrophysical objects. In this paper, we look at the idealized model of a 2D plane parallel isothermal slab (CDL) and at symmetric settings, where both flows have equal parameters. We…

Astrophysics · Physics 2009-11-11 Doris Folini , Rolf Walder

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

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

The properties of supersonic isothermal turbulence influence a variety of astrophysical phenomena, including the structure and evolution of star forming clouds. This work presents a simple model for the structure of dense regions in…

Astrophysics of Galaxies · Physics 2018-02-28 Brant Robertson , Peter Goldreich

We study the growth rate and saturation level of the turbulent dynamo in magnetohydrodynamical simulations of turbulence, driven with solenoidal (divergence-free) or compressive (curl-free) forcing. For models with Mach numbers ranging from…