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Related papers: Clumpy ultracompact HII regions -- III. Cometary m…

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The relative alignments of mid-infrared traced Galactic bubbles are compared to the orientation of the mean Galactic magnetic field in the disk. The orientations of bubbles in the northern Galactic plane were measured and are consistent…

Astrophysics of Galaxies · Physics 2015-06-11 Michael D. Pavel , Dan P. Clemens

In this work, we investigate hot, isentropic compact stars in the limiting cases of static and maximally rotating configurations, focusing on how variations in the symmetry energy of the equation of state derived from covariant density…

High Energy Astrophysical Phenomena · Physics 2026-02-02 Stefanos Tsiopelas , Armen Sedrakian , Micaela Oertel

The Carina Nebula is an extremely bright southern HII region embedded in a giant molecular cloud and contains some of the most massive stars known in our Galaxy. We are undertaking a multi-wavelength study of the Carina Nebula in order to…

Astrophysics · Physics 2015-06-24 K. J. Brooks , J. B. Whiteoak , J. W. V. Storey

Star formation in relic HII regions of the first stars is investigated using magneto-hydrodynamical simulations with a nested grid method that covers 10 orders of magnitude in spatial scale and 20 orders of magnitude in density contrast.…

Solar and Stellar Astrophysics · Physics 2014-11-20 Masahiro N. Machida , Kazuyuki Omukai , Tomoaki Matsumoto

We study the formation and evolution of HII regions around the first stars formed at z=10-30. We use a one-dimensional Lagrangian hydrodynamics code which self-consistently incorporates radiative transfer and non-equilibrium primordial gas…

Astrophysics · Physics 2009-11-10 T. Kitayama , N. Yoshida , H. Susa , M. Umemura

The S254-258 star-forming complex is a place of massive star formation where five OB-stars have created HII regions, visible as optical nebulae, and disrupted the parental molecular gas. In this work, we study the 3D structure of these \HII…

Astrophysics of Galaxies · Physics 2024-02-14 Maria S. Kirsanova , Alexei V. Moiseev , Paul A. Boley

The origin of the observed morphological and kinematic substructure of young star forming regions is a matter of debate. We offer a new analysis of data from simulations of globally gravitationally collapsing clouds of progenitor gas to…

Astrophysics of Galaxies · Physics 2017-11-15 Aleksandra Kuznetsova , Lee Hartmann , Javier Ballesteros-Paredes

The clumping of massive star winds is an established paradigm confirmed by multiple lines of evidence and supported by stellar wind theory. The purpose of this paper is to bridge the gap between detailed models of inhomogeneous stellar…

Solar and Stellar Astrophysics · Physics 2015-06-03 L. M. Oskinova , A. Feldmeier , P. Kretschmar

Recent surveys of dust continuum emission at sub-mm wavelengths have shown that filamentary molecular clouds are ubiquitous along the Galactic plane. These structures are inhomogeneous, with over-densities that are sometimes associated with…

Astrophysics of Galaxies · Physics 2016-01-27 Yanett Contreras , Guido Garay , Jill M. Rathborne , Patricio Sanhueza

Sometimes the early star formation can be found in cold and dense molecular clouds, such as infrared dark cloud (IRDC). Considering star formation often occurs in clustered condition, HII regions may be triggering a new generation of star…

Astrophysics of Galaxies · Physics 2017-06-07 Chuan-Peng Zhang , Jing-Hua Yuan , Jin-Long Xu , Xiao-Lan Liu , Nai-Ping Yu , Nan Li , Li-Ping He , Guo-Yin Zhang , Jun-Jie Wang

We have surveyed a ~0.9-square-degree area of the W3 giant molecular cloud and star-forming region in the 850-micron continuum, using the SCUBA bolometer array on the James Clerk Maxwell Telescope. A complete sample of 316 dense clumps was…

Astrophysics · Physics 2009-06-23 T J T Moore , D E Bretherton , T Fujiyoshi , N A Ridge , J Allsopp , M G Hoare , S L Lumsden , J S Richer

The Large Magellanic Cloud (LMC) exhibits vigorous high-mass star formation, including the HII regions 30~Dor that is the most active site of star formation in the local group. The present paper focuses on the Giant Molecular Cloud (GMC) in…

Interstellar bubbles around O stars are driven by a combination of the star's wind and ionizing radiation output. The wind contribution is uncertain because the boundary between the wind and interstellar medium is difficult to observe.…

Astrophysics of Galaxies · Physics 2014-12-10 Jonathan Mackey , Vasilii V. Gvaramadze , Shazrene Mohamed , Norbert Langer

We have observed the ultracompact HII region G10.6-0.4 with the VLA in 23 GHz continuum and the NH3(3,3) inversion line. By analyzing the optical depth of the line as well as the kinematics, we have detected a flattened, rotating, molecular…

Astrophysics · Physics 2009-11-11 Peter K. Sollins , Paul T. P Ho

An investigation of dust emission associated with a large sample of HII regions has been carried out. Stacked results from this sample suggest that each HII region is at or near the center of a cluster of dense cores, that extends far…

Astrophysics of Galaxies · Physics 2019-11-06 George Bobotsis , Michel Fich

We use fractal analysis to systematically study the clustering strength of the distribution of stars, HII regions, molecular gas, and individual giant molecular clouds in M33 over a wide range of spatial scales. We find a clear transition…

Astrophysics of Galaxies · Physics 2011-09-15 Nestor Sanchez , Neyda Anez , Emilio Alfaro , Mary Crone Odekon

We have discovered a number of very small isolated HII regions 20-30 kpc from their nearest galaxy. The HII regions appear as tiny emission line dots (ELdots) in narrow band images obtained by the NOAO Survey for Ionization in Neutral Gas…

Astrophysics · Physics 2007-05-23 E. V. Ryan-Weber , M. E. Putman , K. C. Freeman , G. R. Meurer , R. L. Webster

To unravel the star formation process, we present a multi-scale and multi-wavelength study of the filamentary infrared dark cloud (IRDC) G333.73+0.37, which hosts previously known two HII regions located at its center. Each HII region is…

Astrophysics of Galaxies · Physics 2022-04-20 L. K. Dewangan

How does turbulence contribute to the formation and structure of the dense interstellar medium (ISM)? Molecular clouds are dense, high-pressure objects. It is usually argued that gravitational confinement causes the high pressures, and that…

Astrophysics · Physics 2017-01-18 Mordecai-Mark Mac Low

We present semi-analytic dynamical models for giant molecular clouds evolving under the influence of HII regions launched by newborn star clusters. In contrast to previous work, we neither assume that clouds are in virial or energetic…

Astrophysics · Physics 2008-11-26 Mark R. Krumholz , Christopher D. Matzner , Christopher F. McKee