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Related papers: Hydrodynamics of Cometary Compact HII Regions

200 papers

Due to its proximity to the Earth and its nearly edge-on geometry, the Orion Bar provides an excellent testbed for detailed models of the structure of HII regions and the surrounding photon-dominated regions. In the present study, a…

Astrophysics of Galaxies · Physics 2015-05-28 Y. Ascasibar , A. C. Obreja , A. I. Diaz

Aspects of the wind-dynamics in symbiotic binaries, colliding winds and accretion, are reviewed. Inconsistencies between theory and observations of the hot star wind are discussed. If the hot star wind were governed by CAK theory, nearly…

Astrophysics · Physics 2007-05-23 Rolf Walder , Doris Folini

Mass-loss and radiation feedback from evolving massive stars produce galactic-scale superwinds, sometimes surrounded by pressure-driven bubbles. Using the time-dependent stellar population typically seen in star-forming regions, we conduct…

Astrophysics of Galaxies · Physics 2024-06-27 A. Danehkar , M. S. Oey , W. J. Gray

The study is devoted to comparing the parameters of the interstellar medium of HII regions in the Kongiu and Groves catalogs for the galaxy NGC 628. The article analyzes the characteristics of star-forming regions, including a comparison of…

Astrophysics of Galaxies · Physics 2026-01-16 Ksenia I. Smirnova , Dmitri S. Wiebe

Massive colliding wind binary stars serve as laboratories for the study of strong-shock physics. In these systems fundamental flow parameters (velocities, densities, directions) are often well known, and photon fields important for Compton…

Astrophysics · Physics 2007-05-23 M. F. Corcoran , J. M. Pittard , I. R. Stevens , D. B. Henley , A. M. T. Pollock

We present radiation-magnetohydrodynamic simulations aimed at studying evolutionary properties of H\,{\normalsize II} regions in turbulent, magnetised, and collapsing molecular clouds formed by converging flows in the warm neutral medium.…

We present hydrodynamical simulations, using a 2-D two component model (ambient medium and pul sar wind have different specific heat ratios), of bow shocks in a representative regime for pu lsar wind driven bow-shock nebulae. We also…

Astrophysics · Physics 2009-11-07 N. Bucciantini

Motivated by the observed connection between molecular hydrogen (H2) and star formation, we present a method for tracking the non-equilibrium abundance and cooling processes of H2 and H2-based star formation in Smoothed Particle…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Charlotte Christensen , Thomas Quinn , Fabio Governato , Adrienne Stilp , Sijing Shen , James Wadsley

We present hydrodynamical simulations of the photoevaporation of a cloud with large-scale density gradients, giving rise to an ionized, photoevaporation flow. The flow is found to be approximately steady during the large part of its…

Astrophysics · Physics 2009-11-11 W. J. Henney , S. J. Arthur , Ma. T. Garcia-Diaz

We present two sets of grid-based hydrodynamical simulations of high-velocity clouds (HVCs) traveling through the diffuse, hot Galactic halo. These HI clouds have been suggested to provide fuel for ongoing star formation in the Galactic…

Astrophysics of Galaxies · Physics 2011-02-11 Fabian Heitsch , Mary E. Putman

We examine the global HI properties of galaxies in quarter-billion particle cosmological simulations using Gadget-2, focusing on how galactic outflows impact HI content. We consider four outflow models, including a new one (ezw) motivated…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Romeel Davé , Neal Katz , Benjamin D. Oppenheimer , Juna A. Kollmeier , David H. Weinberg

We present new analytic theory and radiative transfer computations for the atomic to molecular (HI-to-H2) transitions, and the build-up of atomic-hydrogen (HI) gas columns, in optically thick interstellar clouds, irradiated by…

Astrophysics of Galaxies · Physics 2015-06-19 Amiel Sternberg , Franck Le Petit , Evelyne Roueff , Jacques Le Bourlot

We derive the molecular properties for a sample of 301 Galactic HII regions including 123 ultra compact (UC), 105 compact, and 73 diffuse nebulae. We analyze all sources within the BU-FCRAO Galactic Ring Survey (GRS) of 13CO emission known…

In this paper we make a quantitative study of the hypothesis that the diffuse H-alpha emitted from the discs of spiral galaxies owes its origin to the ionizing photons escaping from HII regions. We use the H-alpha measurements of the…

Astrophysics · Physics 2009-11-07 A. Zurita , J. E. Beckman , M. Rozas , S. Ryder

We present in this paper a list of candidates tidal dwarf galaxies selected among a sample of 117 HII region observed in 11 minor mergers. The classification of the HII regions was performed using the blue absolute magnitude (M$_B$ $<$…

Astrophysics · Physics 2011-02-19 D. L. Ferreiro , M. G. Pastoriza , M. C. Rickes

The observed high covering fractions of neutral hydrogen (HI) with column densities above $\sim 10^{17} \rm{cm}^{-2}$ around Lyman-Break Galaxies (LBGs) and bright quasars at redshifts z ~ 2-3 has been identified as a challenge for…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-25 Alireza Rahmati , Joop Schaye , Richard G. Bower , Robert A. Crain , Michelle Furlong , Matthieu Schaller , Tom Theuns

(abridged) Quantifying the ISM porosity to ionizing photons in nearby galaxies may improve our understanding of the mechanisms leading to Lyman Continuum photons leakage from galaxies. Primitive galaxies with low metal and dust content have…

Since about 25 years ago work has been dedicated to the development of hydrodynamical model atmospheres for cool stars (of A to T spectral type). Despite their obviously sounder physical foundation in comparison with standard hydrostatic…

Astrophysics · Physics 2007-05-23 H. -G. Ludwig , A. Kucinskas

We present an analysis of wind-blown, parsec-sized, mid-infrared bubbles and associated star-formation using GLIMPSE/IRAC, MIPSGAL/MIPS and MAGPIS/VLA surveys. Three bubbles from the Churchwell et al. (2006) catalog were selected. The…

We have observed 10 interacting galaxy pairs using the Fabry-Perot interferometer GH$\alpha$FaS (Galaxy H$\alpha$ Fabry-Perot system) on the $4.2\rm{m}$ William Herschel Telescope (WHT) at the Observatorio del Roque de los Muchachos, La…