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Related papers: Self-Similar Polytropic Champagne Flows in H II Re…

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The dynamical evolution of HII regions with and without stellar motion in dense, structured molecular clouds is studied. Clouds are modeled in hydrostatic equilibrium, with gaussian central cores and external halos that obey r**-2 and r**-3…

Astrophysics · Physics 2011-02-11 Jose Franco , Guillermo Garcia-Segura , Stan Kurtz

The axially symmetric, swirl-free gas dynamics and interlinked motion of a cork stopper provoked by the opening of a champagne bottle are modelled rigorously and studied numerically. The experimental study by Liger-Belair, Cordier \&…

Fluid Dynamics · Physics 2023-12-20 Lukas Wagner , Stefan Braun , Bernhard Scheichl

The development of a bubble plume from a vertical gas-evolving electrode is driven by buoyancy and hydrodynamic bubble dispersion. This canonical fluid mechanics problem is relevant for both thermal and electrochemical processes. We adopt a…

Fluid Dynamics · Physics 2024-11-20 N. Valle , J. W. Haverkort

The diffuse medium in and around galaxies can exist in a multi-phase state: small, cold gas clouds contributing significantly to the total mass embedded in pressure equilibrium with a hotter, more diffuse volume-filling component. Modeling…

Astrophysics of Galaxies · Physics 2022-12-28 Rainer Weinberger , Lars Hernquist

We present a pair of high-resolution smoothed particle hydrodynamics (SPH) simulations that explore the evolution and cooling behavior of hot gas around Milky-Way size galaxies. The simulations contain the same total baryonic mass and are…

Astrophysics · Physics 2015-05-13 Tobias Kaufmann , James S. Bullock , Ariyeh H. Maller , Taotao Fang , James Wadsley

In this second paper of the sequel of two papers, we further investigate the problem of molecular cloud (MC) collision. Anathpindika (2009) (hereafter paper I) considered highly supersonic cloud collisions and examined the effect of bending…

Solar and Stellar Astrophysics · Physics 2015-05-13 S. V. Anathpindika

Emission line profiles of tracer molecule H$_2$CO 140 GHz transition from gravitational core collapsing clouds in the dynamic process of forming protostars are calculated, using a simple ray-tracing radiative transfer model. Three…

Solar and Stellar Astrophysics · Physics 2015-05-13 Yang Gao , Yu-Qing Lou , Kinwah Wu

We present semi-analytical similarity solutions for the inside-out, expansion-wave collapse of initially virialized gas clouds with non-isothermal equations of state. Results are given for the family of negative-index polytropes, but we…

Astrophysics · Physics 2009-10-28 Dean E. McLaughlin , Ralph E. Pudritz

Previous works for a liquid suddenly contacting a gas at a supercritical pressure show the coexistence of both phases and the generation of diffusion layers on both sides of the liquid-gas interface due to thermodynamic phase equilibrium. A…

Fluid Dynamics · Physics 2022-04-25 Jordi Poblador-Ibanez , Branson Davis , William A. Sirignano

Radiative cooling can drive dynamics in multi-phase gas. A dramatic example is hydrodynamic `shattering', the violent, pressure-driven fragmentation of a cooling cloud which falls drastically out of pressure balance with its surroundings.…

Astrophysics of Galaxies · Physics 2025-07-02 Chaoran Wang , S. Peng Oh , Yan-Fei Jiang , Ish Kaul

2d hydrodynamical simulations are performed to examine the evaporation and condensation processes of giant molecular clouds in the hot phase of the interstellar medium. The evolution of cold and dense clouds is calculated in the subsonic…

Astrophysics · Physics 2009-10-31 Wolfgang Vieser , Gerhard Hensler

Guderley's 1942 work on radial shock waves provides cases of self-similar Euler flows exhibiting blowup of primary (undifferentiated) flow variables: a converging shock wave invades a quiescent region, and the velocity and pressure in its…

Fluid Dynamics · Physics 2023-01-23 Helge Kristian Jenssen , Charis Tsikkou

We use molecular dynamics simulations in two dimensions to investigate the possibility that a core-softened potential can reproduce static and dynamic anomalies found experimentally in liquid water: (i) the increase in specific volume upon…

Soft Condensed Matter · Physics 2009-10-31 A. Scala , M. Reza Sadr-Lahijany , N. Giovambattista , S. V. Buldyrev , H. E. Stanley

In this study we give a characterization of semi-geostrophic turbulence by performing freely decaying simulations for the case of constant uniform potential vorticity, a set of equations known as surface semi-geostrophic approximation. The…

Atmospheric and Oceanic Physics · Physics 2016-03-08 Francesco Ragone , Gualtiero Badin

We construct spherical, hydrostatic models of dense molecular cores and Bok globules consisting of two distinct, spatially separate gas components: a central, isothermal region surrounded by a negative-index, polytropic envelope. The clouds…

Astrophysics · Physics 2009-10-31 Charles L. Curry , Christopher F. McKee

Multiphase outflows, revealed by multi-wavelength observations, are crucial in redistributing gas and metals within and around galaxies. These outflows are often modelled theoretically using wind tunnel simulations of a cold ($\sim 10^4$ K)…

Astrophysics of Galaxies · Physics 2025-12-10 Alankar Dutta , Prateek Sharma , Max Gronke

We present deep Very Large Array H66$\alpha$ radio recombination line (RRL) observations of the two cometary HII regions in DR 21. With these sensitive data, we test the "hybrid" bow shock/champagne flow model previously proposed for the DR…

Astrophysics of Galaxies · Physics 2014-03-05 K. Immer , C. Cyganowski , M. J. Reid , K. M. Menten

We propose that galactic shocks propagating through interstellar density fluctuations provide a mechanism for the intermittent replenishment, or "pumping," of the supersonic motions and internal density enhancements observed pervasively…

Astrophysics · Physics 2008-02-03 Paul Kornreich , John Scalo

We show the existence of a new class of initially smooth spherically symmetric self-similar solutions to the non-isentropic Euler-Poisson system. These solutions exhibit supersonic gravitational implosion in the sense that the density…

Analysis of PDEs · Mathematics 2025-03-18 Christopher Alexander , Mahir Hadžić , Matthew Schrecker

The SILCC project (SImulating the Life-Cycle of molecular Clouds) aims at a more self-consistent understanding of the interstellar medium (ISM) on small scales and its link to galaxy evolution. We present three-dimensional…