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Related papers: Resolution of the Distance Ambiguity for Galactic …

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We present high-resolution HI data obtained using the Australia Telescope Compact Array to resolve the near/far distance ambiguities towards a sample of compact HII regions from the Red MSX Source (RMS) survey. The high resolution data are…

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…

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

Using the HI Emission/Absorption method, we resolve the kinematic distance ambiguity and derive distances for 149 of 182 (82%) HII regions discovered by the Green Bank Telescope HII Region Discovery Survey (GBT HRDS). The HRDS is an X-band…

Astrophysics of Galaxies · Physics 2015-06-05 L. D. Anderson , T. M. Bania , Dana S. Balser , Robert T. Rood

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

HII regions are the ionized spheres surrounding high-mass stars. They are ideal targets for tracing Galactic structure because they are predominantly found in spiral arms and have high luminosities at infrared and radio wavelengths. In the…

Astrophysics of Galaxies · Physics 2015-09-09 L. D. Anderson , L. A. Hough , T. V. Wenger , T. M. Bania , Dana S. Balser

We investigate the use of HI data to resolve the near/far ambiguity in kinematic distances of massive young stellar object (MYSO) candidates. Kinematic distances were obtained from 13CO 1-0 spectral line observations with the Mopra…

We present a new, detailed, analysis of the spatial distribution of Galactic HII regions, exploiting a far richer database than used in previous analyses. Galactocentric distances have been derived for 550 objects. Distances from the Sun…

Astrophysics · Physics 2009-11-10 R. Paladini , G. DeZotti , R. D. Davies

We present an HI absorption survey of the central 250 pc of the Galaxy. Very Large Array (VLA) observations were made at 21 cm in the DnC and CnB configurations and have a resolution of ~15"(0.6 pc at the Galactic Center (GC) distance) and…

Astrophysics of Galaxies · Physics 2015-05-20 Cornelia C. Lang , W. Miller Goss , Claudia Cyganowski , Kelsey I. Clubb

Using data from the all-sky Wide-Field Infrared Survey Explorer (WISE) satellite, we made a catalog of over 8000 Galactic HII regions and HII region candidates by searching for their characteristic mid-infrared (MIR) morphology. WISE has…

Astrophysics of Galaxies · Physics 2015-06-18 L. D. Anderson , T. M. Bania , Dana S. Balser , V. Cunningham , T. V. Wenger , B. M. Johnstone , W. P. Armentrout

We spectroscopically identify 101 Galactic HII regions using spectra from the Large Sky Area Multi- Object Fiber Spectroscopic Telescope (LAMOST) survey, cross-matched with an HII region catalog derived from the all-sky Wide-Field Infrared…

Astrophysics of Galaxies · Physics 2018-10-24 Li-Li Wang , A-Li Luo , Wen Hou , Meng-Xin Wang , Bing Du , Li Qin , Jin-Shu Han

We present radio and infrared observations of 4 hyper-compact HII regions and 4 ultra-compact HII regions in the southern Galactic plane. These objects were selected from a blind survey for UCHII regions using data from two new radio…

Astrophysics of Galaxies · Physics 2015-05-18 Tara Murphy , Martin Cohen , Ronald D. Ekers , Anne J. Green , Robin Wark , Vanessa Moss

We present data from mid-infrared Keck Telescope imaging of 18 radio-selected ultra-compact HII region candidates at diffraction-limited resolution. The goal of these observations is to determine the sizes, luminosities, and morphologies of…

Astrophysics · Physics 2008-11-26 Uriel Giveon , Matthew J. Richter , Robert H. Becker , Richard L. White

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 make a comprehensive study of HI absorption toward HII regions located within Galactic longitudes less than 10 degrees. Structures in the extreme inner Galaxy are traced using the longitude-velocity space distribution of this absorption.…

Astrophysics of Galaxies · Physics 2015-06-16 C. Jones , J. M. Dickey , J. R. Dawson , N. M. McClure-Griffiths , L. D. Anderson , T. M. Bania

We report simultaneous H110alpha and H2CO line observations with the NRAO Green Bank Telescope toward 72 H II regions in the SPITZER/GLIMPSE survey area (|l| = 10 deg - 65 deg and |b| </= 1 deg). We used the H110alpha line to establish the…

Astrophysics · Physics 2009-02-16 M. Sewilo , C. Watson , E. Araya , E. Churchwell , P. Hofner , S. Kurtz

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

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

As part of our ongoing HII Region Discovery Survey (HRDS), we report the Green Bank Telescope detection of 148 new angularly-large Galactic HII regions in radio recombination line (RRL) emission. Our targets are located at a declination…

Astrophysics of Galaxies · Physics 2018-02-21 L. D. Anderson , W. P. Armentrout , Matteo Luisi , T. M. Bania , Dana S. Balser , Trey V. Wenger

At low radio frequencies (< 100 MHz), classical HII regions may become optically thick (optical depth > 1) and can be observed as discrete absorption regions against the Galactic nonthermal background emission created by Galactic cosmic ray…

Astrophysics · Physics 2008-11-26 Michael E. Nord , P. A. Henning , R. J. Rand , T. Joseph W. Lazio , Namir E. Kassim
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