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1411. Radio sources in HH 7-11 region
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.
1412. Radio sources in the 6dFGS
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.
1413. Radio sources in the NCP region with the 21CMA
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.
1414. 58 radio sources near BNGSs
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.
1415. Radio sources near North Celestial Pole
ID:
ivo://CDS.VizieR/J/AZh/84/387
Title:
Radio sources near North Celestial Pole
Short Name:
J/AZh/84/387
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have used the RATAN-600 radio telescope to study the spectral characteristics of a uniform sample of 504 radio sources from the NVSS catalog (Cat. VIII/65) near the North Celestial Pole at 6 frequencies from 1.1 to 21.7GHz, with the aim of selecting sources possessing inverted spectra near 22GHz, to be included in the program of the RadioAstron future space VLBI mission. We found 17 radio sources with the desired spectral characteristics. Data from spectral studies over a wide wavelength range testify that the spectral behavior of our sample differs from that for a complete sample of sources with the same initial parameters but selected at 20GHz. We find a 6% deficit of inverted-spectrum sources, which can be explained as an effect of the spectral characteristics of "sub-threshold" sources that were not included in the initial sample at 1.4GHz.
1416. Radio Sources observed with Culgoora Circular Array
ID:
ivo://CDS.VizieR/VIII/35
Title:
Radio Sources observed with Culgoora Circular Array
Short Name:
VIII/35
Date:
21 Oct 2021
Publisher:
CDS
Description:
This is a final, updated and recalibrated list of sources that were observed with the Culgoora Circular Array (CCA) in the interval 1970-1984. The list contains all the sources that were published in the Culgoora-1,2,3 Lists plus additional sources resulting from a survey of 353 Abell clusters of galaxies. The observations were made at 80 MHz and 160 MHz with HPBW in RA of 3.70' and 1.85' respectively. The beamwidth in Dec is wider by sec(30.3 + Dec). This list brings together all CCA measurements of flux density, position, spectral index and angular size, with limiting flux densities of 4 Jy at 80 MHz and 2 Jy at 160 MHz. References to the original Culgoora publications are given for each source. The sources were selected for CCA observations from the Parkes, 4C and Ohio catalogues if an extrapolation of the then existing spectral data indicated that the 80 MHz flux density would be > 5 Jy. In addition, about 300 additional sources were added from lists of special classes of objects such as those discovered at higher frequencies from surveys of the galactic plane, lists of pulsars and supernova remnants, from a list of nearby bright galaxies and finally from a CCA survey of 353 Abell clusters of galaxies. An area of 16'x16' was surveyed about the centres of 3500 fields, resulting in a total survey area of about 0.1 sr at 80 MHz.
1417. Radio sources related to gamma-ray emission
ID:
ivo://CDS.VizieR/J/A+AS/131/11
Title:
Radio sources related to gamma-ray emission
Short Name:
J/A+AS/131/11
Date:
21 Oct 2021
Publisher:
CDS
Description:
Table 2 lists the individual flux density measurements for 47 radio sources as observed with the Effelsberg 100-m telescope.
1418. Radio sources toward galaxy clusters at 30GHz
ID:
ivo://CDS.VizieR/J/AJ/134/897
Title:
Radio sources toward galaxy clusters at 30GHz
Short Name:
J/AJ/134/897
Date:
21 Oct 2021
Publisher:
CDS
Description:
Extragalactic radio sources are a significant contaminant in cosmic microwave background and Sunyaev-Zel'dovich effect experiments. Deep interferometric observations with the BIMA and OVRO arrays are used to characterize the spatial, spectral, and flux distributions of radio sources toward massive galaxy clusters at 28.5GHz. We compute counts of millijansky source fluxes from 89 fields centered on known massive galaxy clusters and 8 noncluster fields.
1419. Radio sources with ultrahigh polarization
ID:
ivo://CDS.VizieR/J/MNRAS/409/821
Title:
Radio sources with ultrahigh polarization
Short Name:
J/MNRAS/409/821
Date:
21 Oct 2021
Publisher:
CDS
Description:
A sample of 129 unresolved radio sources with ultrahigh linear polarization (>30%) has been selected from the NRAO VLA Sky Survey. Such high average linear polarization is unusual in extragalactic sources. Higher resolution Australia Telescope Compact Array and Very Large Array observations confirm the high average polarization but find that most of these sources are extended. The Sloan Digital Sky Survey spectroscopy, where available, shows that the optical counterparts are elliptical galaxies with no detectable emission lines. The optical spectra, radio luminosity, linear size and spectral index of these sources are typical of radio-loud active galactic nuclei.
1420. Radio spectral index 147-1400MHz
ID:
ivo://CDS.VizieR/J/MNRAS/474/5008
Title:
Radio spectral index 147-1400MHz
Short Name:
J/MNRAS/474/5008
Date:
21 Oct 2021
Publisher:
CDS
Description:
The radio spectral index is a powerful probe for classifying cosmic radio sources and understanding the origin of the radio emission. Combining data at 147MHz and 1.4GHz from the TIFR GMRT Sky Survey (TGSS) and the NRAO VLA Sky Survey (NVSS), we produced a large-area radio spectral index map of ~80 per cent of the sky (Dec. >-40deg), as well as a radio spectral index catalogue containing 1396515 sources, of which 503647 are not upper or lower limits. Almost every TGSS source has a detected counterpart, while this is true only for 36 per cent of NVSS sources. We released both the map and the catalogue to the astronomical community. The catalogue is analysed to discover systematic behaviours in the cosmic radio population. We find a differential spectral behaviour between faint and bright sources as well as between compact and extended sources. These trends are explained in terms of radio galaxy evolution. We also confirm earlier reports of an excess of steep-spectrum sources along the galactic plane. This corresponds to 86 compact and steep-spectrum source in excess compared to expectations. The properties of this excess are consistent with normal non-recycled pulsars, which may have been missed by pulsation searches due to larger than average scattering along the line of sight.