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

200 papers

Observations of the starburst galaxy, M82, have been made with the VLA in its A-configuration at 15 GHz and MERLIN at 5 GHz enabling a spectral analysis of the compact radio structure on a scale of < 0.1'' (1.6 pc). Crucial to these…

Astrophysics · Physics 2009-11-07 A. R. McDonald , T. W. B. Muxlow , K. A. Wills , A. Pedlar , R. J. Beswick

Twenty-two powerful radio galaxies have been searched for HI absorption. We find the highest probability of detecting HI in absorption among narrow-line compact (or small) galaxies or galaxies with indication of richer interstellar medium…

Astrophysics · Physics 2007-05-23 R. Morganti , T. A. Oosterloo , G. van Moorsel , C. N. Tadhunter , N. Killeen

We present high-resolution radio observations of a sample of 65 radio sources at low Galactic latitudes. The sources were all observed at 5 GHz with the Very Large Array A-array. MERLIN observations at 5 GHz of the ultracompact HII region…

Astrophysics · Physics 2009-11-10 D. J. Saikia , P. Thomasson , S. Roy , A. Pedlar , T. W. B. Muxlow

We have used the images from the ACS on HST in Halpha, and in the neighboring continuum, to produce flux calibrated images of the large spiral galaxy M51, and the dwarf irregular NGC 4449. From these images we have derived the absolute…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Leonel Gutiérrez , John E. Beckman , Valeria Buenrostro

This paper presents a spectroscopic investigation of 11 HII regions in the nearby galaxy NGC 2403. The HII regions are observed with a long-slit spectrograph mounted on the 2.16 m telescope at XingLong station of National Astronomical…

Astrophysics of Galaxies · Physics 2018-02-14 Ye-Wei Mao , Lin Lin , Xu Kong

VLA radio continuum imaging reveals compact (<8 pc) ~1 mJy radio sources in the central 5" starburst region of the blue compact galaxy Henize 2-10. We interpret these radio knots as extremely young, ultra-dense HII regions. We model their…

Astrophysics · Physics 2009-10-31 Henry A. Kobulnicky , Kelsey E. Johnson

We present Very Large Array observations of the 33 GHz radio continuum emission from 22 local ultraluminous and luminous infrared (IR) galaxies (U/LIRGs). These observations have spatial (angular) resolutions of 30--720 pc (0.07"-0.67") in…

Linear polarization of diffuse Galactic emission is a signature of magnetic fields in the interstellar medium of our Galaxy. Observations at high frequencies are less affected by Faraday depolarization than those at lower frequencies and…

Astrophysics of Galaxies · Physics 2015-05-27 L. Xiao , J. L. Han , W. Reich , X. H. Sun , R. Wielebinski , P. Reich , H. Shi , O. Lochner

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 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

As first data release of a pilot extragalactic HI survey with Five-hundred-meter Aperture Spherical radio Telescope (FAST),we extracted 544 extragalaxies from three-dimensional(3D) spectral data to perform interactive searching and…

Astrophysics of Galaxies · Physics 2025-04-08 Jiangang Kang , Ming Zhu , Mei Ai , Haiyang Yu , Chun Sun

We conduct a Galactic census of Giant HII regions, based on the all sky 6cm dataset of Kuchar & Clark, plus the kinematic distances obtained by Russeil. From an inspection of mid-IR Mid-course Space Experiment (MSX) and far-IR IRAS Sky…

Astrophysics · Physics 2009-11-10 Peter S Conti , Paul A. Crowther

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 the discovery of two small intergalactic HII regions in the loose group of galaxies around the field elliptical NGC 1490. The HII regions are located at least 100 kpc from any optical galaxy but are associated with a number of…

Astrophysics · Physics 2007-05-23 T. Oosterloo , R. Morganti , E. M. Sadler , A. Ferguson , J. M. van der Hulst , H. Jerjen

In this work we analyze the spectroscopic properties of a large number of H ii regions, \sim2600, located in 38 galaxies. The sample of galaxies has been assembled from the face-on spirals in the PINGS survey and a sample described in…

We present Australia Telescope Compact Array observations towards 6 massive star formation regions which, from their strong 24 GHz continuum emission but no compact 8 GHz continuum emission, appeared good candidates for hyper-compact HII…

Astrophysics of Galaxies · Physics 2015-05-13 S. N. Longmore , M. G. Burton , E. Keto , S. Kurtz , A. J. Walsh

We present NOT optical observations of a clump (l = 127.9435 deg, b = +1.8298 deg), embedded in an extended, irregularly shaped, diffuse optical nebula. This condensation shows an emission-line spectrum typical of classic HII regions.…

Astrophysics · Physics 2009-11-10 S. Temporin , R. Weinberger

We present an analysis of multi-wavelength observations of an area of 0.27 deg x 0.27 deg around the Galactic HII region G18.88-0.49, which is powered by an O-type star (age ~10^5 years). The Herschel column density map reveals a shell-like…

Astrophysics of Galaxies · Physics 2020-11-04 L. K. Dewangan , D. K. Ojha , Saurabh Sharma , S. del Palacio , N. K. Bhadari , A. Das

We present mid-IR 21micron images of a sample of radio selected Ultracompact HII (UCHII) regions, obtained with the Midcourse Space Experiment (MSX). All, with one possible exception, are detected at mid-IR wavelengths, sampling the warm…

Astrophysics · Physics 2009-11-07 Paul A. Crowther , Peter S. Conti