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Related papers: How Long Can Tiny HI Clouds Survive?

200 papers

With a view to understand the galaxy/star formation scenario, we investigate the dissipative collapse of a spherical cluster of gas clouds with an isotropic velocity distribution. The time scale for collapse to one tenth radius is studied…

Astrophysics · Physics 2007-05-23 K. Indulekha , G. V. Vijayagovindan , S. Ramadurai

We performed one-dimensional hydrodynamic simulations with detailed cooling, heating and chemical processes to examine the thermal stability of shocked gas in cold neutral medium (CNM) and molecular clouds. We find that both CNM and…

Solar and Stellar Astrophysics · Physics 2015-06-16 Takuhiro Aota , Tsuyoshi Inoue , Yuri Aikawa

We discuss constraints on the rates of stirring and dissipation of MHD turbulence in molecular clouds. Recent MHD simulations suggest that turbulence in clouds decays rapidly, thus providing a significant source of energy input,…

Astrophysics · Physics 2009-11-06 Shantanu Basu , Chigurupati Murali

Evaporation of a liquid drop surrounded by either vapor of the same fluid, or vapor and air, is usually attributed to vapor diffusion -- which, however, does not apply to the former setting, as pure fluids do not diffuse. The present paper…

Fluid Dynamics · Physics 2022-04-05 E. S. Benilov

We follow numerically the nonlinear evolution of the Parker instability in the presence of phase transitions from a warm to a cold HI interstellar medium in two spatial dimensions. The nonlinear evolution of the system favors modes that…

Astrophysics of Galaxies · Physics 2015-05-13 Telemachos Ch. Mouschovias , Matthew W. Kunz , Duncan A. Christie

We numerically examine the influence of the viscosity on the relaxation process of localized clouds in thermally unstable two-phase media, which are locally heated by cosmic ray and cooled by radiation. Pulselike stationary solutions of the…

Pattern Formation and Solitons · Physics 2009-08-12 Hiroki Yatou , Sadayoshi Toh

The ram-pressure acceleration of cold gas by hot outflows plays a crucial role in the dynamics of multiphase galactic winds. Recent numerical studies incorporating radiative cooling have identified a size threshold for idealized cold clouds…

Astrophysics of Galaxies · Physics 2025-12-17 Benedikt S. Seidl , Max Gronke , Ryan Jeffrey Farber , Klaus Dolag

We consider the thermal properties of cold, dense clouds of molecular hydrogen and atomic helium. For cloud masses below 10^-1.7 Msun, the internal pressure is sufficient to permit the existence of particles of solid or liquid hydrogen at…

Astrophysics · Physics 2009-10-31 Mark Wardle , Mark Walker

A table is presented that summarizes published absorption line measurements for the high- and intermediate velocity clouds (HVCs and IVCs). New values are derived for N(HI) in the direction of observed probes, in order to arrive at reliable…

Astrophysics · Physics 2009-11-06 B. P. Wakker

We examine the formation of molecular gas behind shocks in atomic gas using a chemical/dynamical model, particular emphasis is given to constraints the chemistry places on the dynamical evolution. The most important result of this study is…

We present new high-sensitivity high-resolution mm-wave observations of the Onsala 1 ultra-compact HII region that bring to light the internal structure of this massive star forming cloud. The 1.2 mm continuum map obtained with the IRAM…

Astrophysics · Physics 2009-11-10 M. S. N. Kumar , M. Tafalla , R. Bachiller

High-velocity clouds (HVCs) may fuel future star formation in the Milky Way, but they must first survive their passage through the hot halo. While recent work has improved our understanding of the survival criterion for cloud-wind…

Astrophysics of Galaxies · Physics 2025-08-28 Lori E. Porter , Matthew Abruzzo , Greg L. Bryan , Mary Putman , Yong Zheng , Drummond Fielding

We have detected over 400 HI clouds in the lower halo of the Galaxy within the pilot region of the Galactic All-Sky Survey (GASS), a region of the fourth quadrant that spans 18 degrees in longitude, 40 degrees in latitude and is centered on…

We have obtained deep HI observations in the direction of 22 continuum sources without previously detected cold neutral medium (CNM). 18 CNM clouds were detected with the typical HI column density of $3\times10^{18}$ cm$^{-2}$. Our…

Astrophysics · Physics 2007-05-23 Snezana Stanimirovic , Carl Heiles , Nissim Kanekar

The kinetic energy of supersonic turbulence within interstellar clouds is subject to cooling by dissipation in shocks and subsequent line radiation. The clouds are therefore susceptible to a condensation process controlled by the specific…

Astrophysics of Galaxies · Physics 2020-02-05 Eric Keto , George B. Field , Eric G. Blackman

The existence of long (> 100 kpc) HI streams and small (< 20 kpc) free-floating HI clouds is well-known. While the formation of the streams has been investigated extensively, and the isolated clouds are often purported to be interaction…

Astrophysics of Galaxies · Physics 2016-07-27 R. Taylor , J. I. Davies , P. Jachym , O. Keenan , R. F. Minchin , J. Palous , R. Smith , R. Wunsch

Most detected neutral atomic hydrogen (HI) at low redshift is associated with optically bright galaxies. However, a handful of HI clouds are known which appear to be optically dark and have no nearby potential progenitor galaxies, making…

Astrophysics of Galaxies · Physics 2018-05-23 Rhys Taylor , Richard Wünsch , Jan Palouš

We present an analysis of the cold gas phase in a low metallicity starburst generated in a high-resolution hydrodynamical simulation of a gas-rich dwarf galaxy merger as part of the GRIFFIN project. The simulations resolve (4 M$_\odot$ gas…

Many recent models consider the structure of individual interstellar medium (ISM) clouds as a way to explain observations of large parts of galaxies. To compare such models to observations, one must understand how to translate between…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Adam K. Leroy , Cheoljong Lee , Andreas Schruba , Alberto Bolatto , Annie Hughes , Jerome Pety , Karin Sandstrom , Eva Schinnerer , Fabian Walter

We present an analysis of the properties of HI holes detected in 20 galaxies that are part of "The HI Nearby Galaxy Survey" (THINGS). We detected more than 1000 holes in total in the sampled galaxies. Where they can be measured, their sizes…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 I. Bagetakos , E. Brinks , F. Walter , W. J. G. de Blok , A. Usero , A. K. Leroy , J. W. Rich , R. C. Kennicutt