A Sino-German 6cm polarisation survey of the Galactic plane IX. HII regions

Abstract

Large-scale radio continuum surveys provide data to get insights into the physical properties of radio sources. HII regions are prominent radio sources produced by thermal emission of ionised gas around young massive stars. We identify and analyse HII regions in the Sino-German 6cm polarisation survey of the Galactic plane. Objects with flat radio continuum spectra together with infrared and/or Halpha emission were identified as HII regions. For HII regions with small apparent sizes, we cross-matched the 6cm small-diameter source catalogue with the radio HII region catalogue compiled by Paladini and the infrared HII region catalogue based on the WISE data. Extended HII regions were identified by eye by overlaying the Paladini and the WISE HII regions onto the 6cm survey images for coincidences. The TT-plot method was employed for spectral index verification. A total of 401 HII regions were identified and their flux densities were determined with the Sino-German 6cm survey data. In the surveyed area, 76 pairs of sources are found to be duplicated in the Paladini HII region catalogue, mainly due to the non-distinction of previous observations with different angular resolutions, and 78 objects in their catalogue are misclassified as HII regions, being actually planetary nebulae, supernova remnants or extragalactic sources that have steep spectra. More than 30 HII regions and HII region candidates from our 6cm survey data, especially extended ones, do not have counterparts in the WISE HII region catalogue, of which 9 are identified for the first time. Based on the newly derived radio continuum spectra and the evidence of infrared emission, the previously identified SNRs G11.1-1.0, G20.4+0.1 and G16.4-0.5 are believed to be HII regions.

arXiv commentversion after some minor corrections and language editing, full Table 2 - 5 will appear in CDS, accepted for publication in A&A

References in corpus (51)

• A Full-Sky H-alpha Template for Microwave Foreground Prediction
• IRIS: A new generation of IRAS maps
• The WISE Catalog of Galactic HII Regions
• The Distance to the Perseus Spiral Arm in the Milky Way
• Parallaxes and proper motions of interstellar masers toward the Cygnus X star-forming complex. I. Membership of the Cygnus X region
• The observed spiral structure of the Milky Way
• The Green Bank Telescope HII Region Discovery Survey II. The Source Catalog
• Trigonometric Parallaxes of Massive Star Forming Regions: II. Cep A & NGC 7538
• ON the Nature of the Local Spiral Arm of the Milky Way
• Discovery of 35 New Supernova Remnants in the Inner Galaxy
• Trigonometric Parallaxes of Massive Star Forming Regions: I. S 252 & G232.6+1.0
• Trigonometric Parallaxes of 6.7 GHz Methanol Masers
• Parallaxes for W49N and G048.60+0.02: Distant Star Forming Regions in the Perseus Spiral Arm
• Trigonometric parallaxes of star forming regions in the Sagittarius spiral arm
• The spiral structure of our Milky Way Galaxy
• Astrometry of Galactic Star Forming Region Sharpless 269 with VERA : Parallax Measurements and Constraint on Outer Rotation Curve
• MASH-II: More Planetary Nebulae from the AAO/UKST HαSurvey
• A radio catalog of Galactic HII regions for applications from decimeter to millimeter wavelengths
• HASH: the Hong Kong/AAO/Strasbourg H-alpha planetary nebula database
• The Parallax of W43: a Massive Star Forming Complex near the Galactic Bar
• Trigonometric Parallaxes of Star Forming Regions in the Perseus Spiral Arm
• Galactic Supernova Remnant Candidates Discovered by THOR
• Magnetic Fields in Large Diameter HII Regions Revealed by the Faraday Rotation of Compact Extragalactic Radio Sources
• Trigonometric Parallaxes of Massive Star Forming Regions: V. G23.01-0.41 and G23.44-0.18
• Trigonometric Parallaxes of Massive Star Forming Regions: IV. G35.20-0.74 and G35.20-1.74
• Trigonometric parallaxes to star-forming regions within 4 kpc of the galactic center
• A Sino-German lambda6 cm polarization survey of the Galactic plane I. Survey strategy and results for the first survey region
• Finding Distant Galactic HII Regions
• A Sino-German 6cm polarization survey of the Galactic plane VII. Small supernova remnants
• A catalogue of integrated H-alpha fluxes for 1,258 Galactic planetary nebulae
• Spectrophotometric Distances to Galactic H\,{\sc{ii}} Regions
• Trigonometric Parallaxes of Massive Star Forming Regions: G012.88+0.48 and W33
• The SPECFIND V2.0 catalogue of radio cross-identifications and spectra. SPECFIND meets the Virtual Observatory
• A Sino-German 6 cm polarization survey of the Galactic plane II. The region from 129 degree to 230 degree longitude
• A Survey of the Polarized Emission from the Galactic Plane at 1420 MHz with Arcminute Angular Resolution
• New Galactic supernova remnants discovered with IPHAS
• A Sino-German 6 cm polarization survey of the Galactic plane III. The region from 10 degree to 60 degree longitude
• The Arecibo HII Region Discovery Survey
• A CGPS Look at the Spiral Structure of the Outer Milky Way I: Distances and Velocities to Star Forming Regions
• A Green Bank Telescope Survey of Large Galactic HII Regions
• New lambda6cm observations of the Cygnus Loop
• A Sino-German 6cm polarization survey of the Galactic plane IV. The region from 60deg to 129deg longitude
• The Infrared and Radio Fluxes Densities of Galactic HII Regions
• The Coordinated Radio and Infrared Survey for High-mass Star Formation. IV: A new radio selected sample of compact Galactic Planetary Nebulae
• Thermal and non-thermal emission in the Cygnus X region
• Galactic synchrotron emissivity measurements between 250° < l < 355° from the GLEAM survey with the MWA
• New Galactic Planetary Nebulae selected by radio and multi-wavelength characteristics
• A Sino-German 6cm polarisation survey of the Galactic plane - VIII. Small-diameter sources
• GS100-02-41: a new large HI shell in the outer part of the Galaxy
• MIRIS Paα Galactic Plane Survey. I. Comparison with IPHAS Hα in l = 96°-116°
• The Origem Loop

Cited by in corpus (10)

• A global view on star formation: The GLOSTAR Galactic plane survey. II. Supernova Remnants in the first quadrant of the Milky Way
• A population of hypercompact HII regions identified from young HII regions
• A Complete Catalogue of Dusty Supernova Remnants
• COMAP Early Science: VI. A First Look at the COMAP Galactic Plane Survey
• Peering into the Milky Way by FAST: II. Ionized gas in the inner Galactic disk revealed by the piggyback line observations of the FAST GPPS survey
• A global view on star formation: The GLOSTAR Galactic plane survey. IX. Radio Source Catalog III: 2<l<28, 36<l<40, 56<l<60 and |b|<1, VLA B-configuration
• A global view on star formation: The GLOSTAR Galactic plane survey X. Galactic HII region catalog using radio recombination lines
• NE2025: An Updated Electron Density Model for the Galactic Interstellar Medium
• Search for new Galactic Wolf-Rayet stars using Gaia DR3. I. Candidate selection and the follow-up of the bright sample
• A global view on star formation: The GLOSTAR Galactic plane survey XII. Effelsberg's continuum view and data release