Browse
this table...

VLAEN20CM - VLA ELAIS N1, N2, N3 Fields 20-cm Source Catalog

HEASARC
Archive

Overview

The authors have used the Very Large Array (VLA) in C configuration to carry out a sensitive 20-cm radio survey of regions of the sky that have been surveyed in the far-infrared (FIR) over the wavelength range 5 -200 microns (um) with ISO (Infrared Space Observatory) as part of the European Large-Area ISO Survey (ELAIS). As usual in surveys based on a relatively small number of overlapping VLA pointings, the flux limit varies over the area surveyed: from a 5-sigma limit of 0.135 mJy over an area of 0.12 deg2 to 1.15 mJy or better over the whole region covered of 4.22 deg2. In their paper, the authors present the complete radio catalog of 867 sources, 428 of which form a complete sample in the flux range 0.2 - 1.0 mJy. These regions of the sky have previously been surveyed to shallower flux limits at 20 cm with the VLA as part of the VLA D-configuration NVSS (full width at half-maximum, FWHM = 45arcseconds) and VLA-B configuration FIRST (FWHM = 5 arcseconds) surveys. This whole survey has a nominal 5-sigma flux limit a factor of 2 below that of the NVSS; 3.4 deg2 of the survey reaches the nominal flux limit of the FIRST survey and 1.5 deg2 reaches 0.25 mJy, a factor of 4 below the nominal FIRST survey limit. In addition, this survey is at a resolution intermediate between the two surveys and thus is well suited for a comparison of the reliability and resolution-dependent surface brightness effects that affect interferometric radio surveys. The authors have carried out a detailed comparison of their survey and these two independent surveys in order to assess the reliability and completeness of each. Considering the whole sample, they found that to the 5-sigma nominal limits of 2.3 and 1.0 mJy, respectively, the NVSS and FIRST surveys have a completeness of 96+2-3 and 89+2-3 % and a reliability of 99+1-2 and 94+2-2 %.

The radio observations were obtained of three ISO ELAIS survey regions in the Northern celestial hemisphere (N1 1610+5430, N2 1636+4115 and N3 1429+3306) (see Table 1 of the reference paper for the details of the fields and the individual pointings). The observations are made with the Very Large Array (VLA) radio telescope at 1.4 GHz (20 cm) in the VLA C configuration (maximum baseline 3.4 km) with an angular resolution (FWHM) of ~15 arcseconds. The aim of these VLA observations was to obtain uniform coverage of the ELAIS regions with an rms noise limit of ~50 microJansky (uJy).

This table contains the 921 components of 867 total sources detected at a level of >= 5 sigma (44 of which are multiple component sources as defined in Section 4.3 of the reference paper) over a total area of 4.222 deg2. There are also entries describing the properties of the total sources for the 44 multi-component sources (for which the positions have been computed as the flux-weighted average positions of their components), and thus this catalog contains 965 (921 + 44) entries. To filter out the latter, component_id values != 'T' should be selected when searching this table.


Catalog Bibcode

1999MNRAS.302..222C

References

A deep VLA survey at 20 cm of the ISO ELAIS survey regions.
    Ciliegi P., McMahon R.G., Miley G., Gruppioni C., Rowan-Robinson M.,
    Cesarsky C., Danese L., Franceschini A., Genzel R., Lawrence A.,
    Lemke D., Oliver S., Puget J.-L., Rocca-Volmerange B.
   <Mon. Not. R. Astron. Soc. 302, 222 (1999)>
   =1999MNRAS.302..222C

Provenance

This table was originally ingested by the HEASARC in August 2012, based on CDS Catalog J/MNRAS/302/222 file table3.dat. It was last updated in September 2013 to remove a duplicate entry for the source ELAISR J142743+331323.

Parameters

Name
The ELAISR designation of the source as recommended by the Dictionary of Nomenclature of Celestial Objects,, viz., 'ELAISR JHHMMSS+DDMMSSC', where ELAISR stands for 'European Large-Area ISO Survey, Radio', the numerical part is the J2000.0 equatorial position of the source, and 'C' is blank for single sources, 'T' for a combined multi-component source, and 'A', 'B', 'C', etc., for the individual components of a multi-component source. The names were given in the deprecated form 'ELAISR20 JHHMMSS+DDMMSSC' in the printed version of the reference paper, notice.

Component_ID
The component identifier A, B, C, D, or T for the total source, for multi-component sources. This parameter is blank for single-component sources.

RA
The Right Ascension of the radio source in the selected equinox. This was given in J2000.0 coordinates to a precision of 0.01 seconds of time in the table in the published MNRAS paper. For the 44 multi-component sources, the positions for the total sources (component_id = 'T') have been computed as the flux-weighted average positions of their components.

Dec
The Declination of the radio source in the selected equinox. This was given in J2000.0 coordinates to a precision of 0.1 arcseconds in the table in the published MNRAS paper. For the 44 multi-component sources, the positions for the total sources (component_id = 'T') have been computed as the flux-weighted average positions of their components.

LII
The Galactic Longitude of the radio source.

BII
The Galactic Latitude of the radio source.

RA_Error
The rms uncertainty in the Right Ascension of the radio source, in arcseconds.

Dec_Error
The rms uncertainty in the Declination of the radio source, in arcseconds.

Flux_20_cm
The peak flux density of the radio source or component at 1.4 GHz, in mJy/beam.

Flux_20_cm_Error
The rms uncertainty in the peak flux density of the radio source or component at 1.4 GHz, in mJy/beam.

Int_Flux_20_cm
The total flux density of the radio source or component at 1.4 GHz, in mJy.

Int_Flux_20_cm_Error
The rms uncertainty in the total flux density of the radio source or component at 1.4 GHz, in mJy.

Major_Axis
The full-width half-maximum (FWHM) of the non-deconvolved major axis of the radio source or component, in arcseconds.

Major_Axis_Error
The rms uncertainty in the full-width half-maximum (FWHM) of the non-deconvolved major axis of the radio source or component, in arcseconds.

Minor_Axis
The full-width half-maximum (FWHM) of the non-deconvolved minor axis of the radio source or component, in arcseconds.

Minor_Axis_Error
The rms uncertainty in the full-width half-maximum (FWHM) of the non-deconvolved minor axis of the radio source or component, in arcseconds.

Position_Angle
The position angle of the major axis of the radio source or component, measured Eastwards from North, in degrees.

Position_Angle_Error
The rms uncertainty in the position angle of the major axis of the radio source or component, in degrees.

X_Pixel
The X-position of the radio source in the field, in pixels (1 pixel = 3 arcseconds).

Y_Pixel
The Y-position of the radio source in the field, in pixels (1 pixel = 3 arcseconds).

SNR
The signal-to-noise ratio of the radio source detection.

Off_Axis
The off-axis angle of the radio source in the VLA map, in arcminutes.

ELAIS_Field
The ELAIS field designation: N1 for 'N1 1610+5430', N2 for 'N2 1636+4115' and N3 for 'N3 1429+3306'.


Contact Person

Questions regarding the VLAEN20CM database table can be addressed to the HEASARC User Hotline.

Page Author: Browse Software Development Team
Last Modified: 25-Sep-2013