English
Related papers

Related papers: The HI-to-H2 Transition in a Turbulent Medium

200 papers

The Hydrodynamics of Superfluid Turbulence (HST) describes the flows (or counterflows) of HeII in the presence of a chaotic set of vortex filaments, so called superfluid turbulence. The HST equations govern both a slow variation of the…

Other Condensed Matter · Physics 2007-05-23 Sergey K. Nemirovskii , Sergey A. Ponomarenko

Turbulent diffuse molecular clouds can exhibit complicated morphologies caused by the interactions among radiation, chemistry, fluids, and fields. We performed full 3D simulations for turbulent diffuse molecular interstellar media,…

Astrophysics of Galaxies · Physics 2024-07-17 Nannan Yue , Lile Wang , Thomas Bisbas , Donghui Quan , Di Li

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

We investigate the interplay between the ionization radiation from massive stars and the turbulence inside the surrounding molecular gas thanks to 3D numerical simulations. We used the 3D hydrodynamical code HERACLES to model an initial…

Solar and Stellar Astrophysics · Physics 2015-06-05 P. Tremblin , E. Audit , V. Minier , W. Schmidt , N. Schneider

The topological and dynamical features of small scales are studied in the context of decaying magnetohydrodynamic turbulent flows using direct numerical simulations. Joint probability density functions (PDFs) of the invariants of gradient…

Fluid Dynamics · Physics 2015-06-15 Vassilios Dallas , Alexandros Alexakis

Solar radio bursts are strongly affected by radio-wave scattering on density inhomogeneities, changing their observed time characteristics, sizes, and positions. The same turbulence causes angular broadening and scintillation of galactic…

The probabilistic approach to turbulence is applied to investigate density fluctuations in supersonic turbulence. We derive kinetic equations for the probability distribution function (PDF) of the logarithm of the density field, $s$, in…

Astrophysics of Galaxies · Physics 2018-10-24 Liubin Pan , Paolo Padoan , Åke Nordlund

We analyze recent 2D simulations of the nonlinear evolution of the line-deshadowing instability (LDI) in hot-star winds, to quantify how the associated highly clumped density structure can lead to a "turbulent porosity" reduction in…

Solar and Stellar Astrophysics · Physics 2018-01-31 Stanley P. Owocki , Jon O. Sundqvist

Supersonic turbulence in molecular clouds is a key agent in generating density enhancements that may subsequently go on to form stars. The stronger the turbulence - the higher the Mach number - the more extreme the density fluctuations are…

Astrophysics of Galaxies · Physics 2015-05-18 Chris Brunt

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

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

Hyperuniform many-body systems in $d$-dimensional Euclidean space are characterized by completely suppressed (normalized) infinite-wavelength density fluctuations, and appear to be endowed with novel exotic physical properties. In this…

Soft Condensed Matter · Physics 2021-06-09 Duyu Chen , Yu Zheng , Chia-Hao Lee , Sangmin Kang , Wenjuan Zhu , Houlong Zhuang , Pinshane Y. Huang , Yang Jiao

The circumgalactic medium (CGM) is responsive to kinetic disruptions generated by nearby astrophysical events. In this work, we study the saturation and dissipation of turbulent hydrodynamics within the CGM through an extensive array of 252…

Astrophysics of Galaxies · Physics 2024-06-28 Alex Lv , Lile Wang , Renyue Cen , Luis C. Ho

Intermittency in fluid turbulence can be evidentiated through the analysis of Probability Distribution Functions (PDF) of velocity fluctuations, which display a strong non-gaussian behavior at small scales. In this paper we investigate the…

Chaotic Dynamics · Physics 2007-05-23 V. Carbone , P. Giuliani , L. Sorriso-Valvo , P. Veltri , R. Bruno , E. Martines , V. Antoni

We model the complex distribution of atomic hydrogen (HI) in the interstellar medium (ISM) assuming that it is driven entirely by supernovae (SN). We develop and assess two different models. In the first approach, the simulated volume is…

Astrophysics · Physics 2009-11-11 Jacqueline A. Hodge , Avinash A. Deshpande

We use numerical simulations to study the effect of nonlinear MHD waves in a stratified, self-gravitating molecular cloud that is bounded by a hot and tenuous external medium. In a previous paper, we had shown the details of a standard…

Astrophysics · Physics 2009-11-11 Takahiro Kudoh , Shantanu Basu

Magnetohydrodynamic turbulence is able to create hierarchical structures in the interstellar medium that are correlated on a wide range of scales via the energy cascade. We use hierarchical tree diagrams known as dendrograms to characterize…

Astrophysics of Galaxies · Physics 2015-06-05 Blakesley Burkhart , A. Lazarian , Alyssa Goodman , Erik Rosolowsky

We derive hydrodynamics of a prototypical one dimensional model, having variable-range hopping, which mimics passive diffusion and ballistic motion of active, or self-propelled, particles. The model has two main ingredients - the hardcore…

Statistical Mechanics · Physics 2020-05-27 Tanmoy Chakraborty , Subhadip Chakraborti , Arghya Das , Punyabrata Pradhan

Turbulent flows over porous substrates are studied via a systematic exploration of the dependence of the flow properties on the substrate parameters, including permeability $K$, grain pitch $L$, and depth $h$. The study uses direct…

Fluid Dynamics · Physics 2025-04-02 Zengrong Hao , Ricardo García-Mayoral

Colliding supersonic bulk flows shape observable properties and internal physics of various astrophysical objects, like O-star winds, molecular clouds, galactic sheets, binaries, or gamma-ray bursts. Using numerical simulations, we show…

Solar and Stellar Astrophysics · Physics 2014-01-07 Doris Folini , Rolf Walder , Jean M. Favre