English
Related papers

Related papers: Can WNM survive inside Molecular Clouds ?

200 papers

Cold gas clouds embedded in a hot, turbulent medium are expected to be short-lived due to disruptive hydrodynamic instabilities. However, radiative cooling might allow such clouds to survive and grow. We present 3D \texttt{Athena++}…

Astrophysics of Galaxies · Physics 2025-11-17 Ashwin Vergis George , Hitesh Kishore Das , Max Gronke

Stars form within molecular clouds but our understanding of this fundamental process remains hampered by the complexity of the physics that drives their evolution. We review our observational and theoretical knowledge of molecular clouds…

Astrophysics of Galaxies · Physics 2015-06-12 Patrick Hennebelle , Edith Falgarone

The range of microphysical and global dynamical timescales in the central regions of Active Galactic Nuclei (AGN) is sufficiently wide to permit the existence of multiphase structure. In particular, very dense, cool clouds can coexist with…

Astrophysics · Physics 2015-06-24 Z. Kuncic , E. G. Blackman , M. J. Rees

Context. It is almost banal to say that the interstellar medium (ISM) is structurally and thermodynamically complex. But the variety of the governing processes, including stellar feedback, renders the investigation challenging. High…

Astrophysics of Galaxies · Physics 2023-08-30 Marco Monaci , Loris Magnani , Steven N. Shore , Henrik Olofsson , Mackenzie R. Joy

Core-collapse supernova (SN) explosions may occur in the highly inhomogeneous molecular clouds (MCs) in which their progenitors were born. We perform a series of 3-dimensional hydrodynamic simulations to model the interaction between an…

High Energy Astrophysical Phenomena · Physics 2018-10-17 Dong Zhang , Roger A. Chevalier

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

We use the Gaussian-fit results of Paper I to investigate the properties of interstellar HI in the Solar neighborhood. The Warm and Cold Neutral Media (WNM and CNM) are physically distinct components. The CNM spin temperature histogram…

Astrophysics · Physics 2010-04-06 Carl Heiles , T. H. Troland

H2 is the simplest and the most abundant molecule in the ISM, and its formation precedes the formation of other molecules. Understanding the dynamical influence of the environment and the interplay between the thermal processes related to…

Astrophysics of Galaxies · Physics 2016-02-24 Valeska Valdivia , Patrick Hennebelle , Maryvonne Gérin , Pierre Lesaffre

Galactic and intergalactic flows often exhibit relative motion between the cold dense gas and the hot diffuse medium. Such multiphase flows -- involving gas at different temperatures, densities, and ionization states -- for instance,…

Astrophysics of Galaxies · Physics 2025-10-07 Ritali Ghosh , Max Gronke , Prateek Sharma , Alankar Dutta

We have computed line emission cooling rates for the main cooling species in models of interstellar molecular clouds. The models are based on numerical simulations of super-sonic magneto-hydrodynamic (MHD) turbulence. Non-LTE radiative…

Astrophysics · Physics 2009-11-06 M. Juvela , P. Padoan , A Nordlund

To evaluate the effect of turbulent heating in the thermal balance of interstellar clouds, we develop an extension of the log-Poisson intermittency model to supersonic turbulence. The model depends on a parameter, d, interpreted as the…

Astrophysics · Physics 2011-02-11 Liubin Pan , Paolo Padoan

Numerical simulations have explored the possibility to form molecular clouds through either a quasi-static, self-gravitating mechanism or the collision of gas streams or lower-density clouds. They also quantitatively predict the…

Molecular clouds (MC) are the densest and coldest component of the interstellar gas, and the sites of star formation. They are also turbulent and fractal and their masses and sizes span several orders of magnitude. It is also generally…

Astrophysics · Physics 2009-11-07 Javier Ballesteros-Paredes

We have investigated the possibility of molecular cloud formation via the Collision-induced Magnetic Reconnection (CMR) mechanism of the cold neutral medium (CNM). Two atomic gas clouds with conditions typical of the CNM were set to collide…

Astrophysics of Galaxies · Physics 2024-08-27 Shuo Kong , Rowan J. Smith , David Whitworth , Erika T. Hamden

Under the assumptions that molecular clouds are nearly spatially and temporally isothermal and that the density peaks (``cores'') within them are formed by turbulent fluctuations, we argue that cores cannot reach a hydrostatic (or…

To understand the formation of a magnetically dominated molecular cloud out of an atomic cloud, we follow the dynamical evolution of the cloud with a time-dependent axisymmetric magnetohydrodynamic code. A thermally stable warm atomic cloud…

Astrophysics · Physics 2009-11-13 S. Van Loo , S. A. E. G. Falle , T. W. Hartquist , T. J. T. Moore

We present a wide grid of models for the structure and transmission properties of warm absorbers in active galactic nuclei (AGN). Contrary to commonly used constant density models, our absorbing cloud is assumed to be under constant total…

Astrophysics · Physics 2007-05-23 A. Rozanska , R. Goosmann , A. -M. Dumont , B. Czerny

We carried out synthetic observations of interstellar atomic hydrogen at 21cm wavelength by utilizing the magneto-hydrodynamical numerical simulations of the inhomogeneous turbulent interstellar medium (ISM) Inoue and Inutsuka (2012). The…

Physical properties of the tiny scale structures in the cold neutral medium (CNM) of galaxies is a long-standing puzzle. Only a few lines of sights in our Galaxy have been studies with mixed results on the scale-invariant properties of such…

Astrophysics of Galaxies · Physics 2020-01-08 P. K. Vishwakarma , P. Dutta

Chemical processes on the surface of icy grains play an important role in the chemical evolution in molecular clouds. In particular, reactions involving non-energetic hydrogen atoms accreted from the gaseous phase have been extensively…

Astrophysics of Galaxies · Physics 2022-07-20 Masashi Tsuge , Akira Kouchi , Naoki Watanabe