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

200 papers

Using the Owens Valley and Nobeyama Radio Observatory interferometers, we carried out an unbiased search for hot molecular cores and ultracompact UC HII regions toward the high-mass star forming region G19.61--0.23. In addition, we…

Astrophysics · Physics 2009-11-10 R. S. Furuya , R. Cesaroni , S. Takahashi , M. Momose , L. Testi , H. Shinnaga , C. Codella

We present new high spectral resolution observations of 15 high-z ($1.3 \leq$ z $\leq 2.5$) HII Galaxies (HIIG) obtained with MOSFIRE at the Keck Observatory. These data, combined with already published data for another 31 high-z and 107 z…

We use narrow-band Halpha+[NII] imaging data gathered during VESTIGE, a blind survey of the Virgo cluster carried out with MegaCam at the CFHT, to identify HII regions in 385 galaxies showing ionised gas emission. We identify 76645 HII…

Astrophysics of Galaxies · Physics 2026-05-07 A. Boselli , M. Fossati , Y. Roehlly , M. Boquien , J. Braine , P. Cote , J. C. Cuillandre , B. Epinat , L. Ferrarese , S. Gwyn , G. Hensler

We have observed 10 interacting galaxy pairs using the Fabry-Perot interferometer GH$\alpha$FaS (Galaxy H$\alpha$ Fabry-Perot system) on the $4.2\rm{m}$ William Herschel Telescope (WHT) at the Observatorio del Roque de los Muchachos, La…

We present the Multi-Array Galactic Plane Imaging Survey (MAGPIS), which maps portions of the first Galactic quadrant with an angular resolution, sensitivity and dynamic range that surpasses existing radio images of the Milky Way by more…

Astrophysics · Physics 2010-02-23 David J. Helfand , Robert H. Becker , Richard L. White , Adam Fallon , Sarah Tuttle

Observations of millimeter wavelength radio recombination lines (mm-RRLs) are used to search for HII regions in an unbiased way that is complementary to many of the more traditional methods previously used. We carried out targeted mm-RRL…

Astrophysics of Galaxies · Physics 2017-06-07 W. -J. Kim , F. Wyrowski , J. S. Urquhart , K. M. Menten , T. Csengeri

We present high resolution (0.''12 x 0.''079) observations of the ultracompact HII region G10.6-0.4 in 23 GHz radio continuum and the NH3(3,3) line. Our data show that the infall in the molecular material is largely spherical, and does not…

Astrophysics · Physics 2009-11-10 Peter K. Sollins , Qizhou Zhang , Eric Keto , Paul T. P Ho

We present the first subarcsecond submillimeter images of the enigmatic ultracompact HII region (UCHII) G5.89-0.39. Observed with the SMA, the 875 micron continuum emission exhibits a shell-like morphology similar to longer wavelengths. By…

Astrophysics · Physics 2015-03-30 T. R. Hunter , C. L. Brogan , R. Indebetouw , C. J. Cyganowski

Context: The emission line of [CII] at 158 micron is one of the strongest cooling lines of the interstellar medium (ISM) in galaxies. Aims: Disentangling the relative contributions of the different ISM phases to [CII] emission, is a major…

The hydroxyl radical (OH) is found in various environments within the interstellar medium (ISM) of the Milky Way and external galaxies, mostly either in diffuse interstellar clouds or in the warm, dense environments of newly formed low-mass…

In recent years, a number of extragalactic massive star clusters that are still deeply embedded in their birth material have been discovered. These objects represent the youngest stage of massive star cluster evolution yet observed, and the…

Astrophysics · Physics 2007-05-23 Kelsey E. Johnson

We present VLA radio continuum observations at 3.6 and 6 cm of a ~0.65 sq.deg. field in the galactic plane at l=+45deg . These observations are meant to be used in a comparison with ISO observations at 7 and 15 um of the same region. In…

Astrophysics · Physics 2009-10-31 Leonardo Testi , Marcello Felli , Gregory B. Taylor

We present measurements of the singly ionized helium to hydrogen ratio ($n_{He^+}/n_{H^+}$) toward diffuse gas surrounding three Ultra-Compact HII (UCHII ) regions: G10.15-0.34, G23.46-0.20 \& G29.96-0.02. We observe radio recombination…

Astrophysics of Galaxies · Physics 2017-04-12 D. Anish Roshi , E. Churchwell , L. D. Anderson

We have selected a sample of 80 candidates for obscured radio-loud active galactic nuclei and presented their basic optical/near-infrared (NIR) properties in Paper 1. In this paper, we present both high-resolution radio continuum images for…

Astrophysics of Galaxies · Physics 2016-03-16 Ting Yan , John T. Stocke , Jeremy Darling , Emmanuel Momjian , Soniya Sharma , Nissim Kanekar

There is a considerable deficiency in the number of known supernova remnants (SNRs) in the Galaxy compared to that expected. Searches for extended low-surface brightness radio sources may find new Galactic SNRs, but confusion with the much…

High-velocity clouds (HVCs) are neutral or ionised gas clouds in the vicinity of the Milky Way that are characterised by high radial velocities inconsistent with participation in the regular rotation of the Galactic disc. Previous attempts…

Astrophysics of Galaxies · Physics 2017-12-05 Tobias Westmeier

HII regions and planetary nebulae (PNe) both emit at radio and infrared (IR) wavelengths, and angularly small HII regions can be mistaken for PNe. This problem of classification is most severe for HII regions in an early evolutionary stage,…

Astrophysics of Galaxies · Physics 2015-05-30 Loren D. Anderson , A. Zavagno , M. J. Barlow , P. Garcia-Lario , A. Noriega-Crespo

We analyse the internal dynamics of star-forming HII regions and their efficiency in interacting with the ISM. We use GHaFaS (Fabry-Perot) data of the nearby spiral galaxy M83 to perform multiple-Gaussian fitting to the integrated Halpha…

Cosmology and Nongalactic Astrophysics · Physics 2009-09-23 Javier Blasco-Herrera , Kambiz Fathi , John Beckman , Leonel Gutiérrez , Andreas Lundgren , Joan Font , Olivier Hernandez , Claude Carignan

We have used Very Large Array (VLA) observations of the massive star forming regions W49A and Sgr B2, obtained with resolutions from 2\farcs0 to 0\farcs04, to classify the morphologies of nearly 100 ultracompact HII regions. These high…

Astrophysics · Physics 2009-11-11 C. G. De Pree , D. J. Wilner , J. Deblasio , A. J. Mercer , L. E. Davis

Based on the ISO spectral catalogue of compact HII regions by Peeters et al. (2001), we present a first analysis of the hydrogen recombination and atomic fine-structure lines originated in the ionized gas. The sample consists of 34 HII…