- ID:
- ivo://CDS.VizieR/J/MNRAS/366/1265
- Title:
- CENSORS infrared imaging
- Short Name:
- J/MNRAS/366/1265
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Combined EIS-NVSS Survey of Radio Sources (CENSORS) is a 1.4-GHz radio survey selected from the National Radio Astronomy Observatories (NRAO) Very Large Array (VLA) Sky Survey (NVSS) and complete to a flux density of 7.2mJy. It targets the European Southern Observatory (ESO) Imaging Survey (EIS) Patch D, which is a 3x2{deg}^2^ field centred on right ascension 09:51:36.0 and declination 21:00:00 (J2000). This paper presents K-band imaging of 142 of the 150 CENSORS sources. The primary motivation for beginning infrared imaging of the sample was to identify the host galaxies of ~30 per cent of sources for which the EIS I-band imaging failed to produce a likely candidate. In addition, K-band magnitudes allow photometric redshift estimation and IK colours aid the identification of host galaxies (which are typically old, red ellipticals). Of the sources observed in the I and K bands, four remain undetected, possibly indicating high redshifts for the host galaxies, and eight involve complicated radio structures, or several candidate host galaxies, which have yet to be resolved. Thus, the host galaxy identifications are brought to 92 per cent completeness.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/416/1900
- Title:
- CENSORS + other 1.4GHz sources
- Short Name:
- J/MNRAS/416/1900
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents a new grid-based method for investigating the evolution of the steep-spectrum radio luminosity function, with the aim of quantifying the high-redshift cut-off suggested by previous work. To achieve this, the Combined EIS-NVSS Survey of Radio Sources (CENSORS) has been developed; this is a 1.4-GHz radio survey, containing 135 sources complete to a flux density of 7.2mJy, selected from the NRAO VLA Sky Survey (NVSS) over 6deg^2^ of the ESO Imaging Survey Patch D (EISD). The sample is currently 7% spectroscopically complete, with the remaining redshifts estimated via the K-z or I-z magnitude-redshift relation. CENSORS is combined with additional radio data from the Parkes All-Sky, Parkes Selected Regions, Hercules and Very Large Array (VLA) COSMOS samples to provide comprehensive coverage of the radio power versus redshift plane. The redshift distributions of these samples, together with radio source count determinations, and measurements of the local luminosity function, provide the input to the fitting process.
- ID:
- ivo://CDS.VizieR/J/MNRAS/385/1297
- Title:
- CENSORS spectroscopic observations
- Short Name:
- J/MNRAS/385/1297
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Combined EIS-NVSS Survey Of Radio Sources (CENSORS) is a 1.4-GHz radio survey selected from the NRAO VLA Sky Survey (NVSS) and complete to a flux density of 7.2mJy. It targets the ESO Imaging Survey (EIS) Patch D, which is a 3x2deg^2^ field centred on 09:51:36.0-21:00:00 (J2000). This paper presents the results of spectroscopic observations of 143 of the 150 CENSORS sources. The primary motivation for these observations is to achieve sufficient spectroscopic completeness so that the sample may be used to investigate the evolution of radio sources. The observations result in secure spectroscopic redshifts for 63 per cent of the sample and likely redshifts (based on a single emission line, for example) for a further 8 per cent. Following the identification of the quasars and star-forming galaxies in the CENSORS sample, estimated redshifts are calculated for the remainder of the sample via the K-z relation for radio galaxies.
- ID:
- ivo://CDS.VizieR/J/A+AS/134/401
- Title:
- 4C equatorial sample VLA observations. II.
- Short Name:
- J/A+AS/134/401
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- VLA observations at 4.9GHz are given for 144 steep-spectrum 4C sources whose declinations are between -4{deg} and +4{deg} and whose angular sizes are smaller than 30arcsec. The paper contains 150 maps (VLA and 6 MERLIN observations at 1420 or 1658MHz) which are not included here.
- ID:
- ivo://CDS.VizieR/J/ApJ/792/L2
- Title:
- C/2012 F6 (Lemmon) and C/2012 S1 (ISON) maps
- Short Name:
- J/ApJ/792/L2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Results are presented from the first cometary observations using the Atacama Large Millimeter/Submillimeter Array (ALMA), including measurements of the spatially resolved distributions of HCN, HNC, H_2_CO, and dust within the comae of two comets: C/2012 F6 (Lemmon) and C/2012 S1 (ISON), observed at heliocentric distances of 1.5 AU and 0.54 AU, respectively. These observations (with angular resolution ~0.5"), reveal an unprecedented level of detail in the distributions of these fundamental cometary molecules, and demonstrate the power of ALMA for quantitative measurements of the distributions of molecules and dust in the inner comae of typical bright comets. In both comets, HCN is found to originate from (or within a few hundred kilometers of) the nucleus, with a spatial distribution largely consistent with spherically symmetric, uniform outflow. By contrast, the HNC distributions are clumpy and asymmetrical, with peaks at cometocentric radii ~500-1000km, consistent with release of HNC in collimated outflow(s). Compared to HCN, the H_2_ CO distribution in comet Lemmon is very extended. The interferometric visibility amplitudes are consistent with coma production of H_2_CO and HNC from unidentified precursor material(s) in both comets. Adopting a Haser model, the H_2_CO parent scale length is found to be a few thousand kilometers in Lemmon and only a few hundred kilometers in ISON, consistent with the destruction of the precursor by photolysis or thermal degradation at a rate that scales in proportion to the solar radiation flux.
- ID:
- ivo://CDS.VizieR/J/MNRAS/294/607
- Title:
- 7C(G) 151MHz survey of the Galactic plane
- Short Name:
- J/MNRAS/294/607
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Results form a survey of the northern Galactic plane (at declination >=30{deg} at 151MHz made with the Cambridge Low Frequency Synthesis Telescope are presented. This survey is designated 7C(G) - i.e. the Galactic portion of the ongoing 7C surveys. This covers the regions 80{deg}<l<104{deg} and 126{deg}<l<180{deg}, for |b|<=5.5{deg}, and has some coverage to |b|~9{deg}, with a resolution of ~70x70cosec{delta}arcsec^2^ (RAxDec). The observations, data reduction and calibration of this survey are described, and a catalogue of 6262 compact sources, with a completeness limit of ~0.25Jy over most of the survey region, is presented. The catalogue has an rms positional accuracy of better than 10arcsec, and the flux densities are tied to the scale of Roger, Bridle & Costain (1973AJ.....78.1030R) with an accuracy of better than 10 per cent.
- ID:
- ivo://CDS.VizieR/J/ApJS/175/97
- Title:
- CGRaBS: survey of {gamma}-ray blazar candidates
- Short Name:
- J/ApJS/175/97
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe a uniform all-sky survey of bright blazars, selected primarily by their flat radio spectra, that is designed to provide a large catalog of likely {gamma}-ray active galactic nuclei (AGNs). The defined sample has 1625 targets with radio and X-ray properties similar to those of the EGRET blazars, spread uniformly across the |^b^|>10{deg} sky. We also report progress toward optical characterization of the sample; of objects with known R<23, 85% have been classified and 81% have measured redshifts. One goal of this program is to focus attention on the most interesting (e.g., high-redshift, high-luminosity, ...) sources for intensive multiwavelength study during the observations by the Large Area Telescope (LAT) on GLAST.
- ID:
- ivo://CDS.VizieR/J/A+A/564/A99
- Title:
- Chamaeleon-MMS1 NH_3_ (1,1) and (2,2) maps
- Short Name:
- J/A+A/564/A99
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The aim of this study is to investigate the structure and kinematics of the nearby candidate first hydrostatic core Cha-MMS1. Cha-MMS1 was mapped in the NH_3_(1,1) line and the 1.2cm continuum using the Australia Telescope Compact Array, ATCA. The angular resolution of the ATCA observations is 7" (~1000AU), and the velocity resolution is 50m/s. The core was also mapped with the 64-m Parkes telescope in the NH_3_(1,1) and (2,2) lines. Observations from Herschel Space Observatory and Spitzer Space telescope were used to help interpretation. The ammonia spectra were analysed using Gaussian fits to the hyperfine structure. A two-layer model was applied in the central parts of the core where the ATCA spectra show signs of self-absorption.
- ID:
- ivo://CDS.VizieR/J/AJ/124/2351
- Title:
- Chandra Deep Field North survey. XII
- Short Name:
- J/AJ/124/2351
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the relationship between faint X-ray and 1.4GHz radio source populations detected within 3' of the Hubble Deep Field (North) using the 1Ms Chandra (Cat. <J/AJ/122/2810>) and 40{mu}Jy VLA (Cat. <J/ApJ/533/611>) surveys. Within this region, we find that ~42% of the 62 X-ray sources have radio counterparts and ~71% of the 28 radio sources have X-ray counterparts; thus, a 40{mu}Jy VLA survey at 1.4GHz appears to be well matched to a 1Ms Chandra observation.
- ID:
- ivo://CDS.VizieR/J/MNRAS/454/952
- Title:
- Chandra Deep Field-South ATLAS 5.5GHz DR2
- Short Name:
- J/MNRAS/454/952
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new image of the 5.5GHz radio emission from the extended Chandra Deep Field South. Deep radio observations at 5.5GHz were obtained in 2010 and presented in the first data release. A further 76h of integration has since been obtained, nearly doubling the integration time. This paper presents a new analysis of all the data. The new image reaches 8.6{mu}Jy rms, an improvement of about 40% in sensitivity. We present a new catalogue of 5.5GHz sources, identifying 212 source components, roughly 50% more than were detected in the first data release. Source counts derived from this sample are consistent with those reported in the literature for S_5.5GHz_>0.1mJy but significantly lower than published values in the lowest flux density bins (S_5.5GHz_<0.1mJy), where we have more detected sources and improved statistical reliability. The 5.5GHz radio sources were matched to 1.4GHz sources in the literature and we find a mean spectral index of -0.35+/-0.10 for S_5.5GHz_>0.5mJy, consistent with the flattening of the spectral index observed in 5GHz sub-mJy samples. The median spectral index of the whole sample is {alpha}_med_=-0.58, indicating that these observations may be starting to probe the star-forming population. However, even at the faintest levels (0.05<S_5.5GHz_<0.1mJy), 39% of the 5.5GHz sources have flat or inverted radio spectra. Four flux density measurements from our data, across the full 4.5-6.5GHz bandwidth, are combined with those from literature and we find 10% of sources (S_5.5GHz_>~0.1mJy) show significant curvature in their radio spectral energy distribution spanning 1.4-9GHz.