- 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).
Number of results to display per page
Search Results
- 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/
- 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.
- 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:
- 27 Mar 2025 01:27:35
- 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.
- 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.
- 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.
- ID:
- ivo://CDS.VizieR/J/AJ/161/14
- Title:
- The Wide-field VLBA Calibrator Survey (WFCS)
- Short Name:
- J/AJ/161/14
- Date:
- 09 Mar 2022
- Publisher:
- CDS
- Description:
- This paper presents the results of the largest very long baseline interferometry (VLBI) absolute astrometry campaign to date of 13645 radio source observations with the Very Long Baseline Array. Of these, 7220 have been detected, including 6755 target sources that have never been observed with VLBI before. This makes the present VLBI catalog the largest ever published. The positions of the target sources have been determined with the median uncertainty of 1.7mas, and 15542 images of 7171 sources have been generated. Unlike previous absolute radio astrometry campaigns, observations were made at 4.3 and 7.6GHz simultaneously using a single wide-band receiver. Because of the fine spectral and time resolutions, the field of view was 4'-8'-much greater than the 10"-20" in previous surveys. This made possible the use of input catalogs with low position accuracy and the detection of a compact component in extended sources. Unlike previous absolute astrometry campaigns, both steep- and flat-spectrum sources were observed. The observations were scheduled in the so-called filler mode to fill the gaps between other high-priority programs. This was achieved by the development of the totally automatic scheduling procedure.
- ID:
- ivo://CDS.VizieR/VIII/69A
- Title:
- The WISH catalogue at 352 MHz
- Short Name:
- VIII/69A
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Westerbork In the Southern Hemishpere (WISH) is a low-frequency (352MHz) radio survey that covers most of the sky between -25 and -15 degrees (1.60sr) at a wavelength of 92cm to a limiting flux density of approximately 18mJy (5sigma). Due to the very low elevation of the observations, the survey has a much lower resolution in declination than in right ascension (54"x54"cosec{delta}). A correlation with the 1.4GHz NVSS (VIII/65) shows that the positional accuracy is less constrained in declination than in right ascension, but there is no significant systematic error. The correlation with the NVSS was also used to construct a sample of faint Ultra Steep Spectrum sources (file uss.dat, table 2 of the paper). This sample is aimed at increasing the number of known high redshift radio galaxies to allow detailed follow-up studies of these massive galaxies and their environments in the early Universe. WISH is a collaboration between the Netherlands Foundation for Research in Astronomy (NFRA/ASTRON) and the Leiden Observatory. Carlos De Breuck, Yuan Tang, Ger de Bruyn, Huub Rottgering, Wil van Breugel, and Roeland Rengelink. For more information, see the WENSS home page at http://www.strw.leidenuniv.nl/wenss/ or contact wenss.people@strw.leidenuniv.nl
- ID:
- ivo://CDS.VizieR/J/ApJS/148/97
- Title:
- The WMAP First Year Source Catalog (WMAP1)
- Short Name:
- J/ApJS/148/97
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The WMAP mission has mapped the full sky to determine the geometry, content, and evolution of the universe. Full-sky maps are made in five microwave frequency bands to separate the temperature anisotropy of the cosmic microwave background (CMB) from foreground emission, including diffuse Galactic emission and Galactic and extragalactic point sources. We define masks that excise regions of high foreground emission, so CMB analyses can be carried out with minimal foreground contamination. We also present maps and spectra of the individual emission components, leading to an improved understanding of Galactic astrophysical processes.
- ID:
- ivo://CDS.VizieR/J/A+AS/73/103
- Title:
- The 64W part of the WRST Survey
- Short Name:
- J/A+AS/73/103
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a deep 92cm survey down to 4.5mJy (5{sigma}) carried out with the Westerbork Synthesis Radio Telescope (WSRT) of a field in Lynx, previously observed at three other radio frequencies: 6, 21, and 49cm. The observations, totalising 4*12h were made in the redundancy mode, which makes it possible to achieve a high dynamic range. In total, 384 sources above a 5{sigma} peak flux limit were detected, of which 337 form a complete sample.
