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Related papers: The Molecular Properties of Galactic HII Regions

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We resolve the kinematic distance ambiguity for 266 inner Galaxy HII regions out of a sample of 291 using existing HI and 13CO sky surveys. Our sample contains all HII regions with measured radio recombination line (RRL) emission over the…

Astrophysics · Physics 2008-12-18 L. D. Anderson , T. M. Bania

We carried out 13CO J=1-0, CS, and C34S J=2-1 and J=3-2 line observations of molecular clouds associated with 16 ultracompact (UC) HII regions with extended envelopes. The molecular clouds are the ones that give birth to rich stellar…

Astrophysics · Physics 2009-11-10 Kee-Tae Kim , Bon-Chul Koo

We investigated the physical properties of molecular clouds and star formation processes around infrared bubbles which are essentially expanding HII regions. We performed observations of 13 galactic infrared bubble fields containing 18…

Astrophysics of Galaxies · Physics 2016-10-26 Qing-zeng Yan , Ye Xu , Bo Zhang , Deng-rong Lu , Xi Chen , Zheng-hong Tang

We investigate the kinematic properties of Galactic HII regions using radio recombination line (RRL) emission detected by the Australia Telescope Compact Array (ATCA) at 4-10 GHz and the Jansky Very Large Array (VLA) at 8-10 GHz. Our HII…

Astrophysics of Galaxies · Physics 2021-11-24 Dana S. Balser , Trey V. Wenger , L. D. Anderson , W. P. Armentrout , T. M. Bania , J. R. Dawson , John M. Dickey

We present a pilot survey of 21 lines of sight towards UCHII regions in the H2CO 1-1 (6cm) and 2-2 (2cm) transitions, using the H2CO centimeter lines as a molecular gas densitometer. Using Arecibo and Green Bank beam-matched observations,…

Astrophysics of Galaxies · Physics 2011-07-27 Adam Ginsburg , Jeremy Darling , Cara Battersby , Ben Zeiger , John Bally

We report the first high-resolution (sub-arcminute) large-scale mapping $^{12}$CO and $^{13}$CO observations of the molecular clouds associated with the giant outer Galaxy HII region CTB~102 (KR 1). These observations were made using a…

Astrophysics of Galaxies · Physics 2019-05-08 Brandon Marshall , Sung-ju Kang , C. R. Kerton , Youngsik Kim , Minho Choi , Miju Kang

The WISE Catalog of Galactic HII Regions contains $\sim2000$ HII region candidates lacking ionized gas spectroscopic observations. All candidates have the characteristic HII region mid-infrared morphology of WISE $12\,\,\mu\,m$ emission…

Astrophysics of Galaxies · Physics 2015-12-09 L. D. Anderson , W. P. Armentrout , B. M. Johnstone , T. M. Bania , Dana S. Balser , Trey V. Wenger , V. Cunningham

We present a complete sample of molecular clumps containing compact and ultra-compact (UC) HII regions between \ell=10\degr and 60\degr\ and $|b|<1\degr, identified by combining the the ATLASGAL submm and CORNISH radio continuum surveys…

The Green Bank Telescope HII Region Discovery Survey has doubled the number of known HII regions in the Galactic zone 343deg.\leql\leq67deg. with |b|\leq1deg. We detected 603 discrete hydrogen radio recombination line (RRL) components at…

Astrophysics of Galaxies · Physics 2015-05-27 L. D. Anderson , T. M. Bania , Dana S. Balser , Robert T. Rood

We study the molecular and the ionized gas in a possible precursor of an UC HII region to contribute to the understanding of how high-mass stars build-up their masses once they have reached the zero-age main secuence. We carried out…

Astrophysics of Galaxies · Physics 2017-10-11 M. E. Ortega , S. Paron , E. Giacani , M. Celis Peña , M. Rubio , A. Petriella

The [CII] fine--structure line at 158um is an excellent tracer of the warm diffuse gas in the ISM and the interfaces between molecular clouds and their surrounding atomic and ionized envelopes. Here we present the initial results from…

A group of four compact HII regions associated with the well-known 50 km/s molecular cloud is the closest site of on-going star formation to the dynamical center of the Galaxy, at a projected distance of ~6 pc. We present a study of ionized…

Astrophysics of Galaxies · Physics 2015-05-20 F. Yusef-Zadeh , J. H. Lacy , M. Wardle , B. Whitney , H. Bushouse , D. A. Roberts , R. G. Arendt

The Galactic HII region G353.2+0.9 is excited by the massive open cluster Pismis-24. By analyzing (sub-)mm molecular-line and -continuum we study the detailed morphology of the gas and dust, as well as their physical parameters and their…

Astrophysics of Galaxies · Physics 2015-06-03 A. Giannetti , J. Brand , F. Massi , A. Tieftrunk , M. T. Beltran

We derive infrared and radio flux densities of all ~1000 known Galactic HII regions in the Galactic longitude range 17.5 < l < 65 degree. Our sample comes from the Wide-Field Infrared Survey Explorer (WISE) catalog of Galactic \hii regions…

Astrophysics of Galaxies · Physics 2017-09-06 Z. Makai , L. D. Anderson , J. L. Mascoop , B. Johnstone

A set of diffuse interstellar clouds in the inner Galaxy within a few hundred pc of the Galactic plane has been observed at an angular resolution of ~1 arcmin combining data from the NRAO Green Bank Telescope and the Very Large Array. At…

Astrophysics of Galaxies · Physics 2015-06-15 Yurii Pidopryhora , Felix J. Lockman , John M. Dickey , Michael P. Rupen

We present spatially-resolved spectroscopic observations of 10 isolated Galactic HII regions using data from the LAMOST Medium-Resolution Spectroscopic Survey of Nebulae (LAMOST MRS-N). The high spatial resolution of the data allows us to…

We have carried out the largest and most unbiased search for hypercompact (HC) HII regions. Our method combines four interferometric radio continuum surveys (THOR, CORNISH, MAGPIS and White2005) with far-infrared and sub-mm Galactic Plane…

Astrophysics of Galaxies · Physics 2018-11-28 A. Y. Yang , M. A. Thompson , W. W. Tian , S. Bihr , H. Beuther , L. Hindson

We present a catalog of $\sim$52,000 extragalactic HII regions and their spectroscopic properties obtained using Integral Field Spectroscopy (IFS) from MUSE observations. The sample analyzed in this study contains 678 galaxies within the…

Aims: We searched for the molecular outflows from fifteen molecular clouds associated with ultra-compact and compact HII (UCHII/HII) regions and discussed possible gas heating mechanism. Methods: Mapping observations of CO $J=3-2$ and…

Astrophysics · Physics 2009-11-13 Sheng-Li Qin , Jun-Jie Wang , Gang Zhao , Martin Miller , Jun-Hui Zhao
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