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1731. The UTR-2 Very Low-Frequency Sky Survey Data
ID:
ivo://CDS.VizieR/VIII/80
Title:
The UTR-2 Very Low-Frequency Sky Survey Data
Short Name:
VIII/80
Date:
21 Oct 2021
Publisher:
CDS
Description:
The results of the very-low frequency (16.7MHz) survey of discrete sources made with the UTR-2 radio telescope is presented. The survey concerns the declination zones -13{deg} to -2{deg}, 0{deg} to 20{deg}, 30{deg} to 40{deg}, and 41{deg} to 60{deg}. The UTR-2 radio source catalogue contains an estimate of the coordinates and flux densities of 1819 sources measured at a number of the lowest frequencies used in contemporary radio astronomy within the range from 10 to 25 MHz. The catalogue is made of two parts: mean.dat: the averaged values of the coordinates and the corresponding errors, the source flux-density at the middle UTR-2 frequency 16.7 MHz as obtained from measured spectrum of the source at all UTR-2 frequencies and its error, the value of measured low-frequency spectral index with respect to which the estimate of has been obtained, the parameter W characterizing the integral reliability of the obtained source estimates and the corresponding object name from higher-frequency radio survey provided the source has been identified. To indicate the integral readability of the source parameters obtained we used the symbols A, B and C. These reliability estimates take into account the total number of measurements, coordinate scatter, number of frequencies and hour-angle settings at which the source parameters have been evaluated. The highly reliable observation results have been marked with symbol A . The sources whose parameters can be used without an additional analysis are marked with B and sources whose parameters are to be used with care have been marked with C. data.dat: this file contains the experimental estimates of the source coordinates and flux densities as well as their errors at each operating frequency of the UTR-2 in the order of their increasing; the total number (N) of successive observations according to which the estimates were obtained and the number of different hour-angle settings (NRA) of the reception pattern at which the source was observed. In cases when the observations did not allow us to obtain a reliable estimates of a source flux density the catalogue contains only their upper limits which are not accompanied by errors. The approximated values of as well as low-frequency spectral indices are presented only for those sources which have flux density estimates obtained at not less than three different UTR-2 frequencies.
1732. The UTR-2 Very Low-Frequency Sky Survey Data
ID:
ivo://CDS.VizieR/VIII/41
Title:
The UTR-2 Very Low-Frequency Sky Survey Data
Short Name:
VIII/41
Date:
21 Oct 2021
Publisher:
CDS
Description:
The results of the very-low frequency (16.7MHz) survey of discrete sources made with the UTR-2 radio telescope is presented. The survey concerns the declination zones -13{deg} to -2{deg}, 0{deg} to 20{deg}, and 41{deg} to 60{deg}. The UTR-2 radio source catalogue contains an estimate of the coordinates and flux densities of 1819 sources measured at a number of the lowest frequencies used in contemporary radio astronomy within the range from 10 to 25 MHz. The catalogue is made of two parts: mean.dat: the averaged values of the coordinates and the corresponding errors, the source flux-density at the middle UTR-2 frequency 16.7 MHz as obtained from measured spectrum of the source at all UTR-2 frequencies and its error, the value of measured low-frequency spectral index with respect to which the estimate of has been obtained, the parameter W characterizing the integral reliability of the obtained source estimates and the corresponding object name from higher-frequency radio survey provided the source has been identified. To indicate the integral readability of the source parameters obtained we used the symbols A, B and C. These reliability estimates take into account the total number of measurements, coordinate scatter, number of frequencies and hour-angle settings at which the source parameters have been evaluated. The highly reliable observation results have been marked with symbol A . The sources whose parameters can be used without an additional analysis are marked with B and sources whose parameters are to be used with care have been marked with C. data.dat: this file contains the experimental estimates of the source coordinates and flux densities as well as their errors at each operating frequency of the UTR-2 in the order of their increasing; the total number (N) of successive observations according to which the estimates were obtained and the number of different hour-angle settings (NRA) of the reception pattern at which the source was observed. In cases when the observations did not allow us to obtain a reliable estimates of a source flux density the catalogue contains only their upper limits which are not accompanied by errors. The approximated values of as well as low-frequency spectral indices are presented only for those sources which have flux density estimates obtained at not less than three different UTR-2 frequencies.
1733. The VLA-COSMOS survey
ID:
ivo://CDS.VizieR/J/AJ/128/1974
Title:
The VLA-COSMOS survey
Short Name:
J/AJ/128/1974
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a catalog of 246 radio sources found in the central 1{deg} of the COSMOS field at 1.4GHz. The VLA pilot project data have a resolution of 1.9"x1.6" and an rms noise limit of ~25-100{mu}Jy/beam covering 0.837{deg}^2. About 20 radio sources are clearly extended, and most of them appear to be double-lobed radio galaxies. We find evidence for a cluster of seven radio galaxies with an extent of ~10' southeast of the COSMOS field center.
1734. The VLA-COSMOS survey. IV.
ID:
ivo://CDS.VizieR/J/ApJS/188/384
Title:
The VLA-COSMOS survey. IV.
Short Name:
J/ApJS/188/384
Date:
21 Oct 2021
Publisher:
CDS
Description:
In the context of the VLA-COSMOS Deep project, additional VLA A array observations at 1.4GHz were obtained for the central degree of the COSMOS field and combined with the existing data from the VLA-COSMOS Large project. A newly constructed Deep mosaic with a resolution of 2.5" was used to search for sources down to 4{sigma} with 1{sigma}~12uJy/beam in the central 50'x50'. This new catalog is combined with the catalog from the Large project (obtained at 1.5"x1.4" resolution) to construct a new Joint catalog. All sources listed in the new Joint catalog have peak flux densities of >=5{sigma} at 1.5" and/or 2.5" resolution to account for the fact that a significant fraction of sources at these low flux levels are expected to be slightly resolved at 1.5" resolution. All properties listed in the Joint catalog, such as peak flux density, integrated flux density, and source size, are determined in the 2.5" resolution Deep image. In addition, the Joint catalog contains 43 newly identified multi-component sources.
1735. The VLA-COSMOS Survey. V. 324MHz
ID:
ivo://CDS.VizieR/J/MNRAS/443/2590
Title:
The VLA-COSMOS Survey. V. 324MHz
Short Name:
J/MNRAS/443/2590
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present 90cm Very Large Array imaging of the COSMOS field, comprising a circular area of 3.14 square degrees at 8.0"x6.0" angular resolution with an average rms of 0.5mJy/beam. The extracted catalogue contains 182 sources (down to 5.5{sigma}), 30 of which are multicomponent sources. Using Monte Carlo artificial source simulations, we derive the completeness of the catalogue, and we show that our 90cm source counts agree very well with those from previous studies. Using X-ray, NUV-NIR and radio COSMOS data to investigate the population mix of our 90cm radio sample, we find that our sample is dominated by active galactic nuclei. The average 90-20cm spectral index (S_{nu}_{prop.to}{nu}^{alpha}^, where S_{nu}_ is the flux density at frequency {nu} and {alpha} the spectral index) of our 90cm selected sources is -0.70, with an interquartile range from -0.90 to -0.53. Only a few ultra-steep-spectrum sources are present in our sample, consistent with results in the literature for similar fields. Our data do not show clear steepening of the spectral index with redshift. Nevertheless, our sample suggests that sources with spectral indices steeper than -1 all lie at z>~1, in agreement with the idea that ultra-steep-spectrum radio sources may trace intermediate-redshift galaxies (z>~1).
1736. The VLA Low-frequency Sky Survey at 74MHz
ID:
ivo://CDS.VizieR/VIII/79A
Title:
The VLA Low-frequency Sky Survey at 74MHz
Short Name:
VIII/79A
Date:
21 Oct 2021
Publisher:
CDS
Description:
The VLA Low-Frequency Sky Survey (VLSS) is a 74MHz (4m) continuum survey covering the entire sky north of -30{deg} declination. Using the VLA in B- and BnA-configurations, we will map the entire survey region at a resolution of 80" and with an average rms noise of 0.1 Jy/beam. For a detailed description of the survey and its scientific motivations, please see the original proposal to the NRAO skeptical review committee. The VLSS is being made as a service to the astronomical community, and the principal data products are being released to the public as soon as they are produced and verified. Details and access to the images can be found at http://lwa.nrl.navy.mil/VLSS/
1737. The VLBA Galactic Plane Survey (VGaPS)
ID:
ivo://CDS.VizieR/J/AJ/142/35
Title:
The VLBA Galactic Plane Survey (VGaPS)
Short Name:
J/AJ/142/35
Date:
21 Oct 2021
Publisher:
CDS
Description:
We presents accurate absolute positions from a 24 GHz Very Long Baseline Array (VLBA) search for compact extragalactic sources in an area where the density of known calibrators with precise coordinates is low. The goals were to identify additional sources suitable for use as phase calibrators for galactic sources, determine their precise positions, and produce radio images. In order to achieve these goals, we developed a new software package, PIMA, for determining group delays from wide-band data with much lower detection limit. With the use of PIMA we have detected 327 sources out of 487 targets observed in three 24 hour VLBA experiments. Among the 327 detected objects, 176 are within 10 degrees of the Galactic plane. This VGaPS catalogue of source positions, plots of correlated flux density versus projected baseline length, contour plots, as well as weighted CLEAN images and calibrated visibility data in FITS format, are available on the Web at http://astrogeo.org/vgaps. Approximately one half of objects from the 24GHz catalogue were observed at dual band 8.6GHz and 2.3GHz experiments. Position differences at 24GHz versus 8.6/2.3GHz for all but two objects on average are strictly within reported uncertainties. We found that for two objects with complex structure positions at different frequencies correspond to different components of a source.
1738. The VSOP (the VLBI Space Observatory Programme) 5 GHz AGN (Active Galactic Nuclei) Survey Program Analysis Data
ID:
ivo://jvo/isas/darts/halca/halca_vsop_survey_program_data
Title:
The VSOP (the VLBI Space Observatory Programme) 5 GHz AGN (Active Galactic Nuclei) Survey Program Analysis Data
Short Name:
HALCA_AGN
Date:
19 Oct 2021 06:40:34
Publisher:
JVO
Description:
A significant fraction of the mission time of VSOP was to be dedicated to the VSOP Survey Programme of bright compact Active Galactic Nuclei (AGN) at 5 GHz, which was lead by ISAS. The VSOP Survey Sources are an unbiased dataset of 294 targets, of which 82% were successfully observed.
1739. The 37W catalogue of radio sources in M31
ID:
ivo://CDS.VizieR/J/A+AS/61/451
Title:
The 37W catalogue of radio sources in M31
Short Name:
J/A+AS/61/451
Date:
21 Oct 2021
Publisher:
CDS
Description:
The radio continuum emission of the spiral galaxy M31 has been mapped at a wavelength of 21cm with the Westerbork Synthesis Radio Telescope, at an angular resolution of 23"x35", corresponding to a linear resolution of 70x115pc. Five fields have been observed which, when combined, cover the main part of the disk of M31. A catalogue of sources inside the M31 area with a flux density larger than 1mJy (five times the rms noise) is presented.
1740. The Westerbork Northern Sky Survey
ID:
ivo://CDS.VizieR/VIII/62
Title:
The Westerbork Northern Sky Survey
Short Name:
VIII/62
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Westerbork Northern Sky Survey (WENSS) is a low-frequency radio survey that covers the whole sky north of 30{deg} at a wavelength of 92cm (330MHz) to a limiting flux density of approximately 18 mJy (5{sigma}). This survey has a resolution of 54"x54" cosec(delta) and a positional accuracy for strong sources of 1.5". The WENSS project is a collaboration between the Netherlands Foundation for Research in Astronomy (NFRA/ASTRON) and the Leiden Observatory.