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Related papers: The Density Variance--Mach Number Relation in Supe…

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Supersonic turbulence is a large reservoir of suprathermal energy in the interstellar medium. Its dissipation, because it is intermittent in space and time, can deeply modify the chemistry of the gas. We further explore a hybrid method to…

Astrophysics of Galaxies · Physics 2009-11-13 Benjamin Godard , Edith Falgarone , Guillaume Pineau Des Forêts

[abridged] We determine the relationship between turbulence energy and gas density variance for 15 molecular clouds in the Solar neighbourhood. We use the linewidths of the CO molecule as the probe of the turbulence energy (sonic Mach…

Astrophysics of Galaxies · Physics 2017-12-06 Jouni Kainulainen , Christoph Federrath

Complex turbulent motions of magnetized gas are ubiquitous in the interstellar medium. The source of this turbulence, however, is still poorly understood. Previous work suggests that compression caused by supernova shockwaves, gravity, or…

Astrophysics of Galaxies · Physics 2020-02-26 Ankush Mandal , Christoph Federrath , Bastian Körtgen

Turbulence and magnetic fields are components of the interstellar medium and are interconnected through plasma processes. In particular, the magnetic flux transport in the presence of magneto-hydrodynamic (MHD) turbulence is an essential…

High Energy Astrophysical Phenomena · Physics 2025-07-30 C. N. Koshikumo , R. Santos-Lima , M. V. del Valle , E. M. de Gouveia Dal Pino , G. Guerrero , A. Lazarian

We performed numerical simulations of supersonic isothermal turbulence driven by mostly compressive large-scale forcing, using both a static grid and adaptive mesh refinement with an effective resolution N=768^3. After a transient phase…

This paper investigates the statistical properties of isothermal turbulence in both the subsonic and supersonic regimes. The focus is on the influence of the Mach number ($Ma$) and the Reynolds number ($Re$) on both the space-local and…

Fluid Dynamics · Physics 2025-10-16 F. Thiesset , C. Federrath

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 the Milky Way is multi-phase, magnetized and turbulent. Turbulence in the interstellar medium produces a global cascade of random gas motions, spanning scales ranging from 100 parsecs to 1000 kilometres.…

We examine the effects of self-gravity and magnetic fields on supersonic turbulence in isothermal molecular clouds with high resolution simulations and adaptive mesh refinement. These simulations use large root grids (512^3) to capture…

Solar and Stellar Astrophysics · Physics 2015-06-04 David Collins , Alexei G. Kritsuk , Paolo Padoan , Hui Li , Hao Xu , Sergey D. Ustyugov , Michael L. Norman

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 density distribution of supersonic isothermal turbulence plays a critical role in many astrophysical systems. It is commonly approximated by a lognormal distribution with a variance of $\sigma_{s,{\rm V}}^2 \approx \ln(1 + b^2 M_{\rm…

Astrophysics of Galaxies · Physics 2026-01-15 Evan Scannapieco , Marcus Brüggen , Philipp Grete , Liubin Pan

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

Supersonic flows in the interstellar medium (ISM) are believed to be a key driver of the molecular cloud formation and evolution. Among molecular clouds' properties, the ratio between the solenoidal and compressive modes of turbulence plays…

Astrophysics of Galaxies · Physics 2022-05-18 Masato I. N. Kobayashi , Tsuyoshi Inoue , Kengo Tomida , Kazunari Iwasaki , Hiroki Nakatsugawa

An initially planar shock wave propagating into a medium of non-uniform density will be perturbed, leading to the generation of post-shock velocity perturbations. Using numerical simulations we study this phenomenon in the case of…

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

We investigate numerically the combined effects of supersonic turbulence, strong magnetic fields and ambipolar diffusion on cloud evolution leading to star formation. We find that, in clouds that are initially magnetically subcritical,…

Astrophysics · Physics 2009-11-10 Zhi-Yun Li , Fumitaka Nakamura

Several topics in the theory of magnetized turbulence are reviewed with application to star formation and the interstellar medium. The density, pressure, and temperature distribution in a turbulent interstellar medium is described in…

Astrophysics · Physics 2007-05-23 Mordecai-Mark Mac Low

We discuss HD and MHD compressible turbulence as a cloud-forming and cloud-structuring mechanism in the ISM. Results from a numerical model of the turbulent ISM at large scales suggest that the phase-like appearance of the medium, the…

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

We use a suite of 3D simulations of star-forming molecular clouds, with and without stellar feedback, magnetic fields, and driven turbulence, to study the compression and expansion rates of the gas as functions of density. We show that,…

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