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- ID:
- ivo://CDS.VizieR/J/AZh/85/314
- Title:
- Complete sample of flat-spectrum radio sources
- Short Name:
- J/AZh/85/314
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of twenty-year observations of a complete sample of 68 flat-spectrum radio sources with flux densities S3.9GHz>200mJy carried out at centimeter wavelengths with the RATAN-600 radio telescope. Since 1995, we have observed simultaneously at six frequencies between 0.97 and 21.7GHz. Of the 56 sources identified with optical objects, 41 are quasars with redshifts between 0.293 and 3.263. Based on our analysis of the spectral shapes, we divide the sources into four classes. Changes of spectral class for individual sources are fairly rare. Based on the light curves and spectra, in most cases,a flare's evolution is in accordance with a model in which the variations result from the evolution of a shock in the radio jet. The main result of our study is that there is no redshift dependence for the true linear sizes of the radiating regions, the variability indices derived for all 20 years of data or for individual flares, or the peak frequencies of the spectra of the compact radio emission. We suggest that this testifies to an absence of cosmological evolution of the sample quasars, at least to z~3.
- ID:
- ivo://CDS.VizieR/J/other/BSAO/46.28
- Title:
- Complete sample of PMN survey spectra
- Short Name:
- J/other/BSAO/46.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this report we present the results of observations of a complete sample of sources from the PMN Survey. The adopted selection criteria were: flux density >200mJy at the PMN Survey frequency 4.8GHz; 0h<RA<24h; -21{deg}<=Dec<=-17{deg}; |b|>=10(deg} to exclude the galactic plane. Five runs of observations were accomplished in 1995-1996. The observations were made at 0.96, 2.3, 3.9, 7.7 and 11.2GHz at the RATAN-600 radio telescope. For all sources of the sample, flux densities at five frequencies and their simultaneous spectra were determined, accuracies in RA were improved 5-10 times. Identifications with data from the Texas Survey were performed.
- ID:
- ivo://CDS.VizieR/VIII/39
- Title:
- Composite CO Survey of the Milky Way
- Short Name:
- VIII/39
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This survey consists of CO(J=1-0) (115 GHz) spectra for the entire Galactic plane. The latitude coverage varies with longitude and in some regions extends from -25 degrees to +25 degrees. The observations were made with the Columbia/GISS 1.2m telescope in New York City, and a twin telescope on Cerro Tololo in Chile. The angular resolution of the survey is 30' (square), the velocity resolution is 1.3km/s and the sensitivity ranges from about 0.1K/chan to 0.35K/chan. The survey is presented as 720 latitude-velocity maps in FITS format, one for each 30' of longitude from -180.0 deg to +179.5 deg, and one velocity-integrated map covering the entire plane. The velocity range of each file is -300 km/s to +300 km/s. The survey has been updated to include some additional data, more careful reprojections of the regions that were originally mapped in equatorial coordinates, and improved estimates of the absolute calibration of the CO intensities (Digel and Dame 1995, unpublished).
- ID:
- ivo://CDS.VizieR/VII/50
- Title:
- CO Radial Velocities Toward Galactic H II Regions
- Short Name:
- VII/50
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalog contains machine-readable versions of the "Catalog of CO Radial Velocities Toward Galactic HII Regions" (Blitz et al. 1982) and the "Catalog of Carbon Monoxide Observations of Southern Hemisphere HII Regions" (Gillespie et al. 1977) in two separate files. The former is a catalog of 242 molecular cloud complexes that are associated with optical HII regions and includes source names, coordinates, CO radial velocities, antenna temperatures and full width at half-maximum at the position of the strongest CO emission, references for the observations, distances to the stars exciting the HII regions, and optical diameters of the HII regions. The latter is the first CO survey of the southern sky; it was made using the Anglo-Australian 3.9-m optical telescope at 115GHz (2.6-mm wavelength) with a hot-electron bolometer receiver located at the Coude focus. The data were collected during two observing periods (September 1975, April 1976) and include designations, coordinates, median values for the velocities, and distances to the stars exciting the HII regions.
- ID:
- ivo://CDS.VizieR/J/A+A/407/899
- Title:
- Core dominance in extragalactic radio sources
- Short Name:
- J/A+A/407/899
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper, based on a paper by Liu and Zhang (2002, Cat. <J/A+A/381/757>), we have chosen a sample of 542 extragalactic sources (27 BL Lac objects, 300 galaxies (radio galaxies and Seyfert galaxies), and 215 quasars), for which we have calculated the core-dominance parameters and investigated the relation between core-dominance parameter and the core and extended luminosities. The core-dominance parameter of galaxies is smaller than that in quasars, which is smaller than that in BL Lac objects.
- ID:
- ivo://CDS.VizieR/J/AJ/130/2541
- Title:
- Core of the Shapley supercluster at 1.4GHz
- Short Name:
- J/AJ/130/2541
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The core of the Shapley supercluster (A3556, A3558, SC 1327-312, SC 1329-313, and A3562) is an ideal region in which to study the effects of cluster mergers on the activity of individual galaxies. This paper presents the most comprehensive radio continuum investigation of the region, relying on a 63 pointing mosaic obtained with the Very Large Array yielding an areal coverage of nearly 7{deg}^2^.
- ID:
- ivo://CDS.VizieR/J/A+A/611/A99
- Title:
- Cores in HII regions parameters
- Short Name:
- J/A+A/611/A99
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- High-mass stars form in much richer environments than those associated with isolated low-mass stars, and once they reach a certain mass, produce ionised (HII) regions. The formation of these pockets of ionised gas are unique to the formation of high-mass stars (M>8M_{sun}_), and present an excellent opportunity to study the final stages of accretion, which could include accretion through the HII region itself. This study of the dynamics of the gas on both sides of these ionisation boundaries in very young HII regions aims to quantify the relationship between the HII regions and their immediate environments. We present high-resolution (~0.5") ALMA observations of nine HII regions selected from the Red MSX Source (RMS, Lumsden et al., Cat. J/ApJS/208/11) survey with compact radio emission and bolometric luminosities greater than 10^4^L_{sun}_. We focus on the initial presentation of the data, including initial results from the radio recombination line H29{alpha} some complementary molecules, and the 256GHz continuum emission.
- ID:
- ivo://CDS.VizieR/J/A+A/615/A103
- Title:
- CORNISH project. III. UCHII region catalogue
- Short Name:
- J/A+A/615/A103
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A catalogue of 239 ultra-compact HII regions (UCHIIs) found in the CORNISH survey at 5GHz and 1.5-arcsec resolution in the region 10{deg}<l<65{deg}, |b|<1{deg} 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.
- ID:
- ivo://CDS.VizieR/J/ApJS/205/1
- Title:
- CORNISH project. II. Source catalog
- Short Name:
- J/ApJS/205/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The CORNISH (Co-Ordinated Radio 'N' Infrared Survey for High-mass star formation) project is the highest resolution radio continuum survey of the Galactic plane to date. It is the 5GHz radio continuum part of a series of multi-wavelength surveys that focus on the northern GLIMPSE region (10{deg}<l<65{deg}), observed by the Spitzer satellite in the mid-infrared. Observations with the Very Large Array in B and BnA configurations have yielded a 1.5" resolution Stokes I map with a root mean square noise level better than 0.4mJy/beam. Here we describe the data-processing methods and data characteristics, and present a new, uniform catalog of compact radio emission. This includes an implementation of automatic deconvolution that provides much more reliable imaging than standard CLEANing. A rigorous investigation of the noise characteristics and reliability of source detection has been carried out. We show that the survey is optimized to detect emission on size scales up to 14" and for unresolved sources the catalog is more than 90% complete at a flux density of 3.9mJy. We have detected 3062 sources above a 7{sigma} detection limit and present their ensemble properties. The catalog is highly reliable away from regions containing poorly sampled extended emission, which comprise less than 2% of the survey area. Imaging problems have been mitigated by down-weighting the shortest spacings and potential artifacts flagged via a rigorous manual inspection with reference to the Spitzer infrared data. We present images of the most common source types found: HII regions, planetary nebulae, and radio galaxies.
