The Coordinated Radio and Infrared Survey for High-Mass Star Formation III. A catalogue of northern ultra-compact H II regions

Abstract

A catalogue of 239 ultra-compact HII regions (UCHIIs) found in the CORNISH survey at 5 GHz and 1.5" resolution in the region $10^{\circ }<l<65^{\circ },|b|<1^{\circ }$ is presented. This is the largest complete and well-selected sample of UCHIIs to date and provides the opportunity to explore the global and individual properties of this key state in massive star formation at multiple wavelengths. The nature of the candidates was validated, based on observational properties and calculated spectral indices, and the analysis is presented in this work. The physical sizes, luminosities and other physical properties were computed by utilising literature distances or calculating the distances whenever a value was not available. The near- and mid-infrared extended source fluxes were measured and the extinctions towards the UCHIIs were computed. The new results were combined with available data at longer wavelengths and the spectral energy distributions (SEDs) were reconstructed for 177 UCHIIs. The bolometric luminosities obtained from SED fitting are presented. By comparing the radio flux densities to previous observational epochs, we find about 5% of the sources appear to be time variable. This first high-resolution area survey of the Galactic plane shows that the total number of UCHIIs in the Galaxy is ~ 750 - a factor of 3-4 fewer than found in previous large area radio surveys. It will form the basis for future tests of models of massive star formation.

30 pages; accepted for publication in A&A on 21.03.2018

References in corpus (16)

• Trigonometric Parallaxes of Massive Star Forming Regions: VI. Galactic Structure, Fundamental Parameters and Non-Circular Motions
• The Boston University-Five College Radio Astronomy Observatory Galactic Ring Survey
• The UKIDSS Galactic Plane Survey
• The VLA Galactic Plane Survey
• Limiting Accretion onto Massive Stars by Fragmentation-Induced Starvation
• Resolution of the Distance Ambiguity for Galactic HII Regions
• IR Dust Bubbles: Probing the Detailed Structure and Young Massive Stellar Populations of Galactic HII Regions
• The Electron Temperature Gradient in the Galactic Disk
• Understanding Spatial and Spectral Morphologies of Ultracompact H II Regions
• The RMS Survey: Radio observations of candidate massive YSOs in the southern hemisphere
• Monitoring the Large Proper Motions of Radio Sources in the Orion BN/KL Region
• A search for ionized jets towards massive young stellar objects
• The Molecular Properties of Galactic HII Regions
• Time Variation in G24.78+0.08 A1: Evidence for an Accreting Hypercompact H II Region?
• Origin of the Lyman excess in early-type stars
• Near-infrared photometry of Galactic planetary nebulae with the VVV Survey

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