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VLACDFSCAT - VLA Survey of Chandra Deep Field South

HEASARC
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Overview

This table contains some of the results from 20 and 6 cm VLA deep observations of the Chandra Deep Field-South (CDF-S), including the Extended CDF-S (E-CDF-S). In the reference paper, the authors discuss the radio properties of 266 cataloged radio sources, of which 198 are above a 20-cm completeness level reaching down to 43 microJanskies (uJy) at the center of the field. Survey observations made at 6 cm over a more limited region cover the original CDF-S to a comparable level of sensitivity as the 20-cm observations. Of 266 cataloged radio sources, 52 have X-ray counterparts in the CDF-S and a further 37 have counterparts in the E-CDF-S area not covered by the 1 Ms exposure. Using a wide range of material, the authors have found optical or infrared counterparts for 254 radio sources, of which 186 have either spectroscopic or photometric redshifts. Three radio sources have no apparent counterpart at any other wavelength. Measurements of the 20-cm radio flux density at the position of each CDF-S X-ray source detected a further 30 radio sources (not included in this table) above a conservative 3-sigma detection limit. X-ray and submillimeter observations have been traditionally used as a measure of AGN and star formation activity, respectively. These new observations probe the faint end of both the star formation and radio galaxy/AGN population, as well as the connection between the formation and evolution of stars and SMBHs. Both of the corresponding gravitational and nuclear fusion-driven energy sources can lead to radio synchrotron emission. AGN and radio galaxies dominate at high flux densities. Although emission from star formation becomes more prominent at the microjansky levels reached by deep radio surveys, even for the weakest sources, an apparent significant contribution from low-luminosity AGN as well as from star formation is still found.

Notice that are 319 entries in this table corresponding to the 266 catalogued radio sources, due to the fact that some of these sources have multiple components. In such cases, the composite source as well as each of its components are listed as separate entries, e.g., source 7 which has 3 components (A, B and C) has 4 entries in this table.


Catalog Bibcode

2008ApJS..179...71K

References

The VLA Survey of the Chandra Deep Field-South. I. Overview and the Radio Data
   Kellermann, K.I.; Fomalont, E.B.; Mainieri, V.; Padovani, P.; Rosati, P.;
   Shaver, P.; Tozzi, P.; Miller, N.
  <Astrophys. J. Suppl. 179, 71 (2008)>
  =2008ApJS..179...71K

Provenance

This table was created by the HEASARC in November 2008 based on the electronic version of Table 1 from the reference paper which was obtained from the ApJ web site.

Parameters

Name
The source name following the IAU definition for position-based names and using the prefix '[KFM2008]' (for Kellermann, Fomalont, Mainieri 2008) recommended by the Dictionary of Nomenclature of Celestial Objects and the J2000.0 equatorial coordinates of the source.

Source_Flag
This flag parameter is set to 'N' if the radio source is not in the complete 20-cm catalog as defined in the reference paper text.

Source_ID
A running identification (RID) number the authors have found convenient to use. Some sources have multiple components, notice. In such cases, the composite source as well as each of its components (A, B, C, etc) are listed as separate entries in this table. For these composite sources the position given for the combined source is that of the "core" component associated with an optical counterpart or, in a few cases in which there is no observed "core", which the authors believe should be identified with the "core".

Alt_Name
an alternative source name using the prefix '[KFM2008] RID' (for Kellermann, Fomalont, Mainieri 2008 running identification number) and the source ID number, as recommended by the Dictionary of Nomenclature of Celestial Objects.

RA
The Right ascension of the radio source in the selected equinox, as determined from the 1.4 GHz data. This was given in J2000.0 coordinates to a precision of 0.01 seconds of time in the original table.

RA_Error
The RMS uncertainty in the Right Ascension of the radio source, in seconds of time.

Dec
The Declination of the radio source in the selected equinox, as determined from the 1.4 GHz data. This was given in J2000.0 coordinates to a precision of 0.1 arcseconds in the original table.

LII
The Galactic Longitude of the radio source.

BII
The Galactic Latitude of the radio source.

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

SNR_20_cm
The signal-to-noise ratio of the radio source in the 1.4-GHz image.

Flux_20_cm
The 20-cm integrated sky flux density, S_20, of the radio source, in milliJanskies (mJy). (Notice that this was given in microJanskies (uJy) in the original table, and converted into mJy by the HEASARC in order to conform to its standard unit for radio flux densities).

Flux_20_cm_Error
The RMS uncertainty in the 20-cm integrated sky flux density of the radio source, in milliJanskies (mJy). (Notice that this was given in microJanskies (uJy) in the original table, and converted into mJy by the HEASARC in order to conform to its standard unit for radio flux densities).

Angular_Size_Limit
This flag parameter is set to '<' if the corresponding angular size is an upper limit to the actual value.

Angular_Size
The overall angular size of the radio source, in arcseconds, as measured at 20 cm.

Flux_6_cm
The flux density, S_6, of the radio source at 6 cm, in milliJanskies (mJy). (Notice that this was given in microJanskies (uJy) in the original table, and converted into mJy by the HEASARC in order to conform to its standard unit for radio flux densities). In addition to those sources selected as having a peak flux density greater than 5 times the rms noise, the authors have also measured the 6-cm flux density at the position of each of the cataloged 20-cm sources.

Flux_6_cm_Error
The RMS uncertainty in the flux density of the radio source at 6 cm, in milliJanskies (mJy). (Notice that this was given in microJanskies (uJy) in the original table, and converted into mJy by the HEASARC in order to conform to its standard unit for radio flux densities).

Spectral_Index
The spectral index, alpha, of the radio source between 6 and 20 cm as defined by the relation flux density S_nu ~ (frequency)-alpha.

Spectral_Index_Error
The RMS uncertainty in the spectral index, alpha, of the radio source between 6 and 20 cm.

Redshift
The redshift of the most likely optical counterpart to the radio source. Where available, the authors have given spectroscopic redshifts; otherwise they present photometric values. See Mainieri et al. (2008, ApJS, 179, 95) for more details.

Rmag
The R magnitude of the most likely optical counterpart to the radio source. In the case of multicomponent sources, where possible, the authors show the magnitude for the associated radio component. See Mainieri et al. (2008, ApJS, 179, 95) for more details.

CXO_ID
The Chandra ID for the X-ray counterpart to the radio source, as taken from Giacconi et al. (2002, ApJS, 139, 369) or from the E-CDF-S data of Lehmer et al. (2005, aApJS, 161, 21). Sources from the E-CDF-S have the prefix E. In the case of multicomponent sources, where possible, the authors give the X-ray identification for the associated radio component.

Log_CXO_Flux
The log of the Chandra full-band flux of the X-ray counterpart to the radio source, in the range from 0.5 to 10 keV, in ergs cm-2 s-1. In the case of multicomponent sources, where possible, the authors give the value for the associated radio component.

Log_Lx
The log of the Chandra full-band X-ray luminosity of the X-ray counterpart to the radio source, in ergs s-1.

Log_Lrad
The log of the 1.4 GHz (20 cm) rest-frame radio luminosity of the radio source, in W Hz-1 (107 erg s-1 -Hz). K-corrections were applied based on the spectral index, if available; otherwise, assuming a value of 0.7 for the spectral index.


Contact Person

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

Page Author: Browse Software Development Team
Last Modified: 21-Nov-2008