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ATHDFS3FRQ - Australia Telescope Hubble Deep Field-South 2.5, 5.2 and 8.7-GHz Source Catalog

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Overview

Deep radio observations of a wide region centered on the Hubble Deep Field-South (HDF-S) have been performed, providing one of the most sensitive sets of radio observations acquired on the Australia Telescope Compact Array (ATCA) to date. A central rms of ~ 10 microJy is reached at four frequencies (1.4, 2.5, 5.2, and 8.7 GHz). In this table, the full source catalogs from the 2.5, 5.2, and 8.7 GHz observations are presented to complement the data for the 1.4 GHz observations which were presented in Paper II (Huynh et al., 2005, AJ, 130, 1373, available at the HEASARC as the ATHDFS1P4G table) in this series, along with a detailed analysis of image quality and noise. The authors also have produced a consolidated catalog of all of their ATCA observations of the HDF-S by matching sources across all four of the frequencies in their survey (available at the HEASARC as the ATHDFSCCAT table).

The details of the observations and data reduction are discussed in detail in Paper I of this series (Norris et al., 2005, AJ, 130, 1358) and summarized in Table 1 of the reference paper. The observations consist of single pointings centered on RA (J2000.0) = 22h 33m 25.96s, Dec (J2000.0) = -60o 38' 09.0" (2.5 GHz), and RA (J2000.0) = 22h 32m 56.22s, Dec (J2000.0) = -60o 33' 02.7" (5.2 and 8.7 GHz). The 5.2 and 8.7 GHz observations are centered on the HST WFPC field, while the 2.5 GHz observations were pointed halfway between the WFPC field and a bright confusing source to allow the bright source to be well cleaned from the 2.5 GHz image.

At 5 sigma, the 5.2 and 8.7 GHz catalogs have over 96% reliability. At 2.5 GHz, the authors have enough statistics to examine the 5 - 5.5 sigma sources, and find that these are only about 40% reliable. With a SNR greater than 5.5 sigma, the 2.5 GHz catalog would have about 99% reliability. The authors thus cut off the catalogs at 5.5, 5, and 5 sigma for 2.5, 5.2, and 8.7 GHz, respectively. The final catalogs have 71, 24, and 6 sources at 2.5, 5.2, and 8.7 GHz, respectively. Given a prior 1.4 GHz position, it may be feasible to push the detection limit lower than 5 sigma. The authors searched for low-SNR sources by matching 3 - 5 sigma sources that lie within 2 sigma positional uncertainty of a 1.4 GHz source. The positional uncertainty was determined by adding the average 1.4 GHz uncertainty (1.1") in quadrature with the positional uncertainty of a 3 sigma source. At 2.5 GHz the allowed positional offset is 3.8", and for 5.2 and 8.7 GHz it is 2.8". Thus, there are 71, 18, and 2 sources at 2.5, 5.2, and 8.7 GHz, respectively, which are low-SNR high-frequency counterparts to 1.4 GHz sources. The authors included these sources in supplementary catalogs.

This HEASARC table contains all 101 primary sources detected at 2.5, 5.2, and 8.7 GHz, as well as the 91 supplementary sources described above (the latter are flagged by having source_flag values of 'S'), for a grand total of 192 radio sources.


Catalog Bibcode

2007AJ....133.1331H

References

Radio observations of the Hubble Deep Field-South region.
III. The 2.5, 5.2, and 8.7 GHz catalogs and radio source properties.
    Huynh M.T., Jackson C.A., Norris R.P.
   <Astron. J., 133, 1331-1344 (2007)>
   =2007AJ....133.1331H

Provenance

This table was created by the HEASARC in December 2012 based on the CDS Catalog J/AJ/130/1371 files table47.dat, table58.dat and table68.dat, which contain the entire contents of Tables 4, 5, 6, 7 and 8 from the published paper.

Parameters

Name
The source designation recommended by the CDS Dictionary of Nomenclature of Celestial Objects, e.g., for 2.5-GHz sources, using the prefix '[HJN2007] 2.5GHz' for Huynh, Jackson, Norris 2007 2.5-GHz and the source number, e.g., '[HJN2007] 2.5GHz 1' for 2.5-GHz source number 1, for 5.2-GHz sources, the prefix '[HJN2007] 5.2GHz' and for 8.7-GHz sources, the prefix '[HJN2007] 8.7GHz'. The numbering for the supplementary sources starts from the end of the primary sources: thus, the sources named '[HJN2007] 2.5GHz 72-142', '[HJN2007] 5.2GHz 25-42' and '[HJN2007] 8.7GHz 7-8' are all supplementary sources.

Frequency
The frequency corresponding to the source detection, 2.5 GHz, 5.2 GHz or 8.7 GHz, in GHz.

Source_Flag
This flag parameter is set to 'S' to differentiate supplementary sources (see the Overview above for a definition of this class) from the primary sources of higher statistical significance.

RA
The Right Ascension of the radio source in the selected equinox. The RA was given in J2000.0 coordinates to a precision of 0.01 seconds of time in the original tables.

Dec
The Declination of the radio source in the selected equinox. The Dec was given in J2000.0 coordinates to a precision of 0.1 arcseconds in the original table.

RA_Error
The 1-sigma error in the Right Ascension of the radio source, in arcseconds.

Dec_Error
The 1-sigma error in the Declination of the radio source, in arcseconds.

LII
The Galactic Longitude of the radio source.

BII
The Galactic Latitude of the radio source.

Flux
The radio source peak flux density, in millijanskys (per beam). The values given here are not corrected for the systematic effects described in Section 3 of the reference paper. ATCA fluxes are generally estimated to be accurate to about 10%.

Int_Flux
The radio source integrated flux density, in millijanskys.

Int_Flux_Flag
This flag parameter is set to '2' to indicates that the Gaussian fit has likely resulted in a poor integrated flux density.

Major_Axis
The deconvolved major axis (FWHM) of the radio source, in arcseconds. The value is only given for successfully deconvolved sources.

Minor_Axis
The deconvolved minor axis (FWHM) of the radio source, in arcseconds. The value is only given for successfully deconvolved sources.

Position_Angle
The deconvolved position angle (PA, measured from North through East) of the source, in degrees. The value is only given for successfully deconvolved sources.

SNR
The signal-to-noise ratio (SNR) of the detection, calculated as the value of the IMSAD fitted peak divided by the local rms noise.


Contact Person

Questions regarding the ATHDFS3FRQ database table can be addressed to the HEASARC User Hotline.

Page Author: Browse Software Development Team
Last Modified: 10-Dec-2012