- ID:
- ivo://CDS.VizieR/J/AZh/80/978
- Title:
- Radio sources identifications at DE=10-12.5deg
- Short Name:
- J/AZh/80/978
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The results of 0.97, 2.3, 3.9, 7.7, 11.1 and 21.7GHz observations of a complete sample of radio sources obtained on the RATAN-600 radio telescope are presented. The sample is comprised of sources from the 4.85-GHz MGB survey, and contains all sources at declinations 10-12.5 degrees (J2000) with galactic latitudes |b|>15 degrees and flux densities S(4.85)>200mJy. Optical identifications have been obtained for about 86% of the radio sources with flat spectra and 59% of those with steep spectra.
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Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/118/625
- Title:
- Radio sources in Abell 2125 and 2645
- Short Name:
- J/AJ/118/625
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Abell clusters 2125 and 2645 have different radio source populations, despite being very similar in richness (Abell class 4) and redshift (0.25). The number density of radio sources in Abell 2125 is almost an order of magnitude more than that in Abell 2645, based on observations to the same optical and radio luminosities of the two clusters. About 30% of the radio sources in Abell 2125 shows signs of star formation, with the largest concentration of them in the southwest clump 2Mpc from the cluster center.
- ID:
- ivo://CDS.VizieR/J/ApJS/120/147
- Title:
- Radio sources in 14 Abell clusters
- Short Name:
- J/ApJS/120/147
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a VLA C-configuration imaging survey of 14 rich Abell clusters. The observations were undertaken with the intent of characterizing the galaxy orbits within the cluster by combining galaxy redshifts with indicators of orbital shape. We present maps of the observed clusters, detailed maps of resolved sources detected in the survey, comparisons with optical images of the clusters, and tables of source parameters for all detected sources with measured flux values.
- ID:
- ivo://CDS.VizieR/J/ApJ/252/102
- Title:
- Radio sources in bright spiral galaxies. II.
- Short Name:
- J/ApJ/252/102
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Statistically complete samples comprising 33 bright spiral galaxies that are strong radio sources were selected. Sixteen of the galaxies have integrated radio-to-optical flux ratios greater than 10 times the median value for normal spirals. The remainder contain radio cores <=20" in size and stronger than 90mJy at 1415MHz or 60mJy at 2695MHz. High-resolution (2" at 1413MHz or 0.6" at 4885MHz) maps of these galaxies were made with the Very Large Array. The radio sources are usually confined to the central 1kpc of the galaxies, lying within and extending parallel to their stellar disks. There is no evidence for ejection from central components. Most of the sources appear to be coextensive with regions of intense star formation (bolometric luminosities ~10^10-10^11L_{Sun}). The typical radio luminosity, ~10^21^W/Hz/sr at 1413MHz, of the resolved sources can be explained by synchrotron radiation from supernova remnants (SNRs) produced at the rate of ~1/yr. Five of the radio sources are <=1pc in size and probably are not related to star formation or SNRs. The radio and 10-{mu}m flux densities of the extended sources are roughly proportional. The bolometric mass-to luminosity ratios in some active regions are too low to have been maintained for a Hubble time. Nearly all of the strong, extended radio sources are found in galaxies with nearby companions, so most of the episodic bursts of star formation are apparently triggered by galaxy-galaxy interactions.
- ID:
- ivo://CDS.VizieR/J/A+AS/115/345
- Title:
- Radio sources in fields near G160.9+2.6 (HB9)
- Short Name:
- J/A+AS/115/345
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalogue of the 408MHz and 1420MHz radio sources in the region centered near Right Ascension 4h58m and Declination 46degrees (epoch 1950), i.e. near the supernova remnant HB9. The observations were made with the Synthesis Telescope at the Dominion Radio Astrophysical Observatory, near Penticton, Canada. 494 sources at 408MHz and 255 sources at 1420MHz were detected. 408-1420MHz spectral indices for 101 common sources were derived. The 408MHz source list was compared with the 4850MHz sources from the Green Bank catalog. Spectral indices were determined for 165 common sources. We also compared the source lists with the IRAS and ROSAT point source catalogs for that region and have identified 16 radio sources with IRAS point sources and 3 radio sources with X-ray sources.
- ID:
- ivo://CDS.VizieR/J/MNRAS/358/1159
- Title:
- Radio sources in HDF and HFF
- Short Name:
- J/MNRAS/358/1159
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- 18 days of MERLIN data and 42h of A-array VLA data at 1.4GHz have been combined to image a 10-arcmin field centred on the Hubble Deep Field (HDF). This area also includes the Hubble Flanking Fields (HFF). A complete sample of 92 radio sources with S1.4>40{mu}Jy was detected using the VLA data alone and then imaged with the MERLIN+VLA combination. The combined images offer (i) higher angular resolution (synthesized beams of diameter 0.2-0.5arcsec), (ii) improved astrometric accuracy, and (iii) improved sensitivity compared with VLA-only data.
- ID:
- ivo://CDS.VizieR/J/ApJS/125/427
- Title:
- Radio sources in HH 7-11 region
- Short Name:
- J/ApJS/125/427
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the Very Large Array, a sensitive radio survey at 6 and 3.6 cm was carried out in the HH 711 region. The data were acquired in 10 observing runs between 1991 and 1998 with several VLA configurations, and the angular resolutions are about 4-5". A total of 44 radio sources were detected in the 8'x8' region centered at this HH complex. The majority of these sources, at least 26 of them, are believed to be associated with young objects in the cloud.
- ID:
- ivo://CDS.VizieR/J/MNRAS/375/931
- Title:
- Radio sources in the 6dFGS
- Short Name:
- J/MNRAS/375/931
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have identified 7824 radio sources from the 1.4GHz NRAO VLA Sky Survey (NVSS, Cat. <VIII/65>) with galaxies brighter than K=12.75mag in the Second Incremental Data Release of the 6 degree Field Galaxy Survey (6dFGS DR2, Cat. <VII/249>). The resulting sample of redshifts and optical spectra for radio sources over an effective sky area of 7076deg^2^ (about 17 per cent of the celestial sphere) is the largest of its kind ever obtained. NVSS radio sources associated with galaxies in the 6dFGS span a redshift range 0.003<z<0.3 and have median z{bar}=0.043. Through visual examination of 6dF spectra we have identified the dominant mechanism for radio emission from each galaxy. 60 per cent are fuelled by star formation and 40 per cent are fuelled by an active galactic nucleus (AGN) powered by a supermassive black hole. We have accurately determined the local radio luminosity function (RLF) at 1.4GHz for both classes of radio source and have found it to agree well with other recent determinations. From the RLF of star-forming galaxies we derive a local star formation density of 0.022+/-0.001M_{sun}_/yr/Mpc^3^, in broad agreement with recent determinations at radio and other wavelengths.
- ID:
- ivo://CDS.VizieR/J/ApJ/832/190
- Title:
- Radio sources in the NCP region with the 21CMA
- Short Name:
- J/ApJ/832/190
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of 624 radio sources detected around the North Celestial Pole (NCP) with the 21 Centimeter Array (21CMA), a radio interferometer dedicated to the statistical measurement of the epoch of reionization (EoR). The data are taken from a 12hr observation made on 2013 April 13, with a frequency coverage from 75 to 175MHz and an angular resolution of ~4'. The catalog includes flux densities at eight sub-bands across the 21CMA bandwidth and provides the in-band spectral indices for the detected sources. To reduce the complexity of interferometric imaging from the so-called "w" term and ionospheric effects, the present analysis is restricted to the east-west baselines within 1500m only. The 624 radio sources are found within 5deg around the NCP down to ~0.1Jy. Our source counts are compared, and also exhibit a good agreement, with deep low-frequency observations made recently with the GMRT and MWA. In particular, for fainter radio sources below ~1 Jy, we find a flattening trend of source counts toward lower frequencies. While the thermal noise (~0.4mJy) is well controlled to below the confusion limit, the dynamical range (~10^4^) and sensitivity of current 21CMA imaging are largely limited by calibration and deconvolution errors, especially the grating lobes of very bright sources, such as 3C061.1, in the NCP field, which result from the regular spacings of the 21CMA. We note that particular attention should be paid to the extended sources, and their modeling and removal may constitute a large technical challenge for current EoR experiments. Our analysis may serve as a useful guide to the design of next generation low-frequency interferometers like the Square Kilometre Array.
- ID:
- ivo://CDS.VizieR/J/ApJS/185/124
- Title:
- 58 radio sources near BNGSs
- Short Name:
- J/ApJS/185/124
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a preliminary survey of 58 radio sources within the isoplanatic patches (r<25") of bright (11<R<12) stars suitable for use as natural guide stars with high-order adaptive optics (AO). An optical and near-infrared imaging survey was conducted utilizing tip-tilt corrections in the optical and AO in the near-infrared. Spectral energy distributions were fit to the multi-band data for the purpose of obtaining photometric redshifts using the Hyperz code. Several of these photometric redshifts were confirmed with spectroscopy, a result that gives more confidence to the redshift distribution for the whole sample. Additional long-wavelength data from Spitzer, SCUBA, SHARC2, and VLA supplement the optical and near-infrared data. We find the sample generally follows and extends the magnitude-redshift relation found for more powerful local radio galaxies. The survey has identified several reasonably bright (H=19-20) objects at significant redshifts (z>1) that are now within the capabilities of the current generation of AO-fed integral-field spectrographs. These objects constitute a unique sample that can be used for detailed ground-based AO studies of galactic structure, evolution, and active galactic nucleus formation at high redshift.
