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Related papers: Study of Molecular Clouds associated with HII Regi…

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We examine the triggering process of molecular cloud formation around diffuse HII regions. We calculate the time evolution of the shell as well as of the HII region in a two-phase neutral medium, solving the UV and FUV radiative transfer,…

Astrophysics · Physics 2011-02-11 Takashi Hosokawa , Shu-ichiro Inutsuka

We attempt to characterise the chemical properties of a sample of massive clumps of IRDCs through multi-molecular line observations. We also search for possible evolutionary trends among the derived chemical parameters. The clumps are…

Astrophysics of Galaxies · Physics 2015-06-17 Oskari Miettinen

Spatial association of clumps from different tracers turns out to be a valuable tool to determine the physical properties of molecular clouds. It provides a reliable estimate for the $X$-factors, serves to trace the density of clumps seen…

Astrophysics of Galaxies · Physics 2018-02-14 Todor V. Veltchev , Volker Ossenkopf-Okada , Orlin Stanchev , Nicola Schneider , Sava Donkov , Ralf S. Klessen

Turbulent fragmentation determines where and when protostellar cores form, and how they contract and grow in mass from the surrounding cloud material. This process is investigated, using numerical models of self-gravitating molecular cloud…

Astrophysics · Physics 2010-04-06 Ralf Klessen

High-mass stars form in much richer environments than those associated with isolated low-mass stars, and once they reach a certain mass, produce ionised (HII) regions. The formation of these pockets of ionised gas are unique to the…

The role of feedback from massive stars is believed to be a key element in the evolution of molecular clouds. We use high-resolution 3D SPH simulations to explore the dynamical effects of a single O7 star located at the centre of a…

Astrophysics of Galaxies · Physics 2015-06-05 S. Walch , A. P. Whitworth , T. Bisbas , R. Wunsch , D. Hubber

Most recent numerical simulations suggest that bipolar HII regions, powered by O-type stars, can be formed at the interface of two colliding clouds. To observationally understand the birth of O-type stars, we present a detailed…

Astrophysics of Galaxies · Physics 2019-06-19 L. K. Dewangan , H. Sano , R. Enokiya , K. Tachihara , Y. Fukui , D. K. Ojha

We report on a multi-wavelength (IR to cm) and multi-resolution (1 mas to 20 arcsec) exploration of high-mass star formation regions in the Galactic plane, at longitudes observable from the Southern Hemisphere. Our source sample was…

Astrophysics · Physics 2007-05-23 V. Minier , M. G. Burton , T. Hill , C. R. Purcell , S. Longmore , A. J. Walsh , F. Herpin

Recent 1.2-mm continuum observations have shown the giant HII region NGC3576 to be embedded in the centre of an extended filamentary dust-cloud. The bulk of the filament away from the HII region contains a number of clumps seen only at…

Astrophysics of Galaxies · Physics 2009-09-08 C. R. Purcell , V. Minier , S. N. Longmore , Ph. André , A. J. Walsh , P. Jones , F. Herpin , T. Hill , M. R. Cunningham , M. G. Burton

We analyse extinction maps of nearby Giant Molecular Clouds to forge a link between driving processes of turbulence and modes of star formation. Our investigation focuses on cloud structure in the column density range above the self…

Astrophysics of Galaxies · Physics 2015-05-28 J. Rowles , D. Froebrich

The {\it Planck} Galactic Cold Clumps (PGCCs) are the possible representations of the initial conditions and the very early stages of star formation. With an objective to understand better the star and star cluster formation, we probe the…

Astrophysics of Galaxies · Physics 2018-09-19 Somnath Dutta , Soumen Mondal , Manash R Samal , Jessy Jose

The formation of stars is inextricably linked to the structure of their parental molecular clouds. Here we take a number of nearby giant molecular clouds (GMCs) and analyse their column density and mass distributions. This investigation is…

Astrophysics of Galaxies · Physics 2015-05-18 D. Froebrich , J. Rowles

In order to investigate the origin of the interstellar turbulence, detailed observations in the CO J=1--0 and 3--2 lines have been carried out in an interacting region of a molecular cloud with an HII region. As a result, several 1,000 to…

Context. Massive-star formation triggered by the expansion of HII regions. Aims. To understand if sequential star formation is taking place at the periphery of the HII region Sh2-219. Methods. We present 12CO(2-1) line observations of this…

Astrophysics · Physics 2009-11-11 L. Deharveng , B. Lefloch , F. Massi , J. Brand , S. Kurtz , A. Zavagno , J. Caplan

We present arcsecond resolution 1.4mm observations of the high mass star forming region, Sharpless 2-157, that reveal the cool dust associated with the first stages of star formation. These data are compared with archival images at optical,…

Astrophysics of Galaxies · Physics 2015-06-04 Chian-Chou Chen , Jonathan P. Williams , Jagadheep D. Pandian

We present a SCUBA submillimetre (450 & 850 micron) survey of the environment of 105 IRAS point sources, selected from the Wood & Churchwell (1989a) and Kurtz, Churchwell & Wood (1994) radio ultracompact (UC) HII region surveys. We detected…

Astrophysics · Physics 2009-11-11 M. A. Thompson , J. Hatchell , A. J. Walsh , G. H. Macdonald , T. J. Millar

Molecular clouds, which harbor the birthplaces of stars, form out of the atomic phase of the interstellar medium (ISM). We aim to characterize the atomic and molecular phases of the ISM and set their physical properties into the context of…

Magnetic fields are ubiquitous and essential in star formation. In particular, their role in regulating formation of stars across diverse environments like HII regions needs to be well understood. In this study, we present magnetic field…

Astrophysics of Galaxies · Physics 2021-04-28 R. Devaraj , D. P. Clemens , L. K. Dewangan , A. Luna , T. P. Ray , J. Mackey

Supernovae from core-collapse of massive stars drive shocks into the molecular clouds from which the stars formed. Such shocks affect future star formation from the molecular clouds, and the fast-moving, dense gas with compressed magnetic…

Astrophysics of Galaxies · Physics 2019-11-06 William T. Reach , Le Ngoc Tram , Matthew Richter , Antoine Gusdorf , Curtis DeWitt

We present a large-scale simultaneous survey of the CO isotopologues ($\rm {}^{12}{CO}$, $\rm{}^{13}{CO}$, and $\rm{C}{}^{18}{O}$) J = 1 ${-}$ 0 line emission toward the Galactic plane region of l = 106.65$^\circ$ to 109.50$^\circ$ and b =…

Astrophysics of Galaxies · Physics 2022-03-30 Chun-Xue Li , Hong-Chi Wang , Yue-Hui Ma , Miao-Miao Zhang , Chong Li , Yu-Qing Zheng