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Related papers: A search for hypercompact HII regions in the Galac…

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We present new criteria for selecting HII regions from the Infrared Astronomical Satellite (IRAS) Point Source catalogue (PSC), based on an HII region catalogue derived manually from the all-sky Wide-field Infrared Survey Explorer (WISE).…

Astrophysics of Galaxies · Physics 2018-03-14 Qing-Zeng Yan , Ye Xu , A. J. Walsh , J. P. Macquart , G. C. MacLeod , Bo Zhang , P. J. Hancock , Xi Chen , Zheng-Hong Tang

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

The Palomar Integral Field Spectrograph was used to probe a variety of environments in nine nearby galaxies that span a range of morphological types, luminosities, metallicities, and infrared-to-blue ratios. For the first time,…

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 report multifrequency radio continuum and hydrogen radio recombination line observations of HII regions near l=24.8d b=0.1d using the Giant Metrewave Radio Telescope (GMRT) at 1.28 GHz (n=172), 0.61 GHz (n=220) and the Very Large Array…

Astrophysics · Physics 2011-08-02 N. G. Kantharia , W. M. Goss , D. Anish Roshi , Niruj R. Mohan , Francois Viallefond

The formation of hypercompact (HC) HII regions is an important stage in massive star formation. Spectral line and continuum observations can explore its dynamic conditions. We present high angular resolution observations carried out with…

Astrophysics of Galaxies · Physics 2014-09-29 Chuan-Peng Zhang , Jun-Jie Wang , Jin-Long Xu , Friedrich Wyrowski , Karl M. Menten

We present 7mm Very Large Array continuum images of the starburst galaxy M82. On arcsecond scales, two-thirds of the 7mm continuum consists of free-free emission from HII regions. In the subarcsecond resolution map, we identify 14 compact…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-13 Chao-Wei Tsai , Jean L. Turner , Sara C. Beck , David S. Meier , Paul T. P. Ho

We present a new catalog of HII regions based on the integral field spectroscopy (IFS) data of the extended CALIFA and PISCO samples. The selection of HII regions was based on two assumptions: a clumpy structure with high contrast of…

We present a multiwavelength study of the ultra compact HII region associated with IRAS 20178+4046. This enables us to probe the different components associated with this massive star forming region. The radio emission from the ionized gas…

Astrophysics · Physics 2009-11-13 A. Tej , S. K. Ghosh , V. K. Kulkarni , D. K. Ojha , R. P. Verma , S. Vig

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

We report subarcsecond-resolution VLA imaging of the centers of four nearby spiral galaxies: IC 342, Maffei II, NGC 2903, and NGC 6946. In each galaxy, 7 - 12 compact radio continuum sources were identified within the central 15" x 15".…

By collecting the information from 24 previously published lists and catalogs, we produce a comprehensive catalog (Master Catalog) of 1442 Galactic HII regions. For each object, we quote the original fluxes and diameters as well as the…

Using deep Subaru/FOCAS spectra of 34 HII regions in both the inner and outer parts of the extended ultraviolet (XUV) disc galaxy NGC 4625 we have measured an abundance gradient out to almost 2.5 times the optical isophotal radius. We…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Q. E. Goddard , F. Bresolin , R. C. Kennicutt , E. V. Ryan-Weber , F. F. Rosales-Ortega

This review discussed near- and mid- infrared observations of ultracompact (UC) HII regions. The importance of ISO mid-IR fine-structure nebular lines is emphasised since only a small fraction of UCHII regions are observed directly in the…

Astrophysics · Physics 2009-11-11 Paul Crowther

We present deep optical spectroscopy of eight HII regions located in the anticentre of the Milky Way. The spectra were obtained at the 10.4m GTC and 8.2m VLT. We determined Te([NII]) for all objects and Te([OIII]) for six of them. We also…

Astrophysics of Galaxies · Physics 2017-08-16 C. Esteban , X. Fang , J. Garcia-Rojas , L. Toribio San Cipriano

We present multiwavelength investigation of morphology, physical-environment, stellar contents and star formation activity in the vicinity of star-forming region Sh 2-100. It is found that the Sh 2-100 region contains seven HII regions of…

Astrophysics of Galaxies · Physics 2015-05-18 M. R. Samal , A. K. Pandey , D. K. Ojha , S. K. Ghosh , V. K. Kulkarni , N. Kusakabe , M. Tamura , B. C. Bhatt , M. A. Thompson , R. Sagar

We present a detailed characterization of the population of compact radio-continuum sources in W51 A using subarcsecond VLA and ALMA observations. We analyzed their 2-cm continuum, the recombination lines (RL's) H77$\alpha$ and H30$\alpha$,…

Astrophysics of Galaxies · Physics 2020-08-26 Rudy Rivera-Soto , Roberto Galván-Madrid , Adam Ginsburg , Stan Kurtz

The Southern Galactic Plane Survey (SGPS) is a project to image the HI line emission and 1.4 GHz continuum in the fourth quadrant of the Milky Way at high resolution using the Australia Telescope Compact Array (ATCA) and the Parkes Radio…

The distribution of metals in the Galaxy provides important information about galaxy formation and evolution. HII regions are the most luminous objects in the Milky Way at mid-infrared to radio wavelengths and can be seen across the entire…

Astrophysics of Galaxies · Physics 2015-05-28 Dana S. Balser , Robert T. Rood , T. M. Bania , L. D. Anderson

We present the first high spatial resolution radio continuum survey of the southern Galactic plane. The CORNISH project has mapped the region defined by $295^{\circ} < l < 350^{\circ}$; $|b| < 1^{\circ}$ at 5.5-GHz, with a resolution of…