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VLA Hubble Deep Field 20-cm Source Catalog

Metadata Updated: September 19, 2025

The authors have conducted a deep radio survey with the Very Large Array (VLA) at 1.4 GHz of a region containing the Hubble Deep Field (HDF). This survey overlaps previous observations at 8.5 GHz allowing them to investigate the radio spectral properties of microJansky sources to flux densities greater than 40 µJy (µJy) at 1.4 GHz and greater than 8 uJy at 8.5 GHz. A total of 371 sources have been catalogued at 1.4 GHz as part of a complete sample within 20 arcminutes of the HDF. The differential source count for this region is only marginally sub-Euclidean and is given by n(S) = (8.3 +/- 0.4) S^(-2.4 +/- 0.1) sr<sup>-1</sup> Jy<sup>-1</sup>. Above about 100 uJy the radio source count is systematically lower in the HDF as compared to other fields. The authors conclude that there is clustering in this radio sample on size scales of 1 to 40 arcminutes. The 1.4 GHz-selected sample shows that the radio spectral indices are preferentially steep (mean spectral index of 0.85) and that the sources are moderately extended with average angular size Theta = 1.8". Optical identification with disk-type systems at z ~ 0.1 - 1 suggests that synchrotron emission, produced by supernovae remnants, is powering the radio emission in the majority of sources. In 1996 November, the authors observed a field centered on the Hubble Deep Field (RA, Dec (J2000.0) = (12<sup>h</sup> 36<sup>m</sup> 49.4<sup>s</sup>, 62<sup>o</sup> 12' 58.00") for a total of 50 hours at 20 cm in the A configuration of the VLA. They reached an rms noise level near the center of the field of 7.5 uJy. They adopted 40 uJy as the formal completeness limit over the entire 1 degree field in their untapered naturally weighted 2 arcseconds image. The authors identified 314 sources within 20 arcminutes of the field center (20% power contour). They found 57 additional sources within this same region (presumably resolved at 2" resolution) in lower resolution (3.5 and 6") tapered images above completeness levels of 50 uJy at 3.5" resolution and 75 uJy at 6" resolution, making a grand total of 371 radio sources detected at 1.4 GHz within 20 arcminutes of the phase center of the field. This table was created by the HEASARC in June 2012 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/533/611">CDS Catalog J/ApJ/533/611</a> file table2.dat. This is a service provided by NASA HEASARC .

Access & Use Information

Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

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Dates

Metadata Created Date April 11, 2025
Metadata Updated Date September 19, 2025

Metadata Source

Harvested from NASA Data.json

Additional Metadata

Resource Type Dataset
Metadata Created Date April 11, 2025
Metadata Updated Date September 19, 2025
Publisher High Energy Astrophysics Science Archive Research Center
Maintainer
Identifier ivo://nasa.heasarc/vlahdf20cm
Data Last Modified 2025-09-10
Category Astrophysics
Public Access Level public
Bureau Code 026:00
Metadata Context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
Schema Version https://project-open-data.cio.gov/v1.1/schema
Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
Harvest Object Id 9dc755c6-1ea6-4a58-86c6-e7c1b6ce6de4
Harvest Source Id 58f92550-7a01-4f00-b1b2-8dc953bd598f
Harvest Source Title NASA Data.json
Homepage URL https://heasarc.gsfc.nasa.gov/W3Browse/all/vlahdf20cm.html
Program Code 026:000
Source Datajson Identifier True
Source Hash dafefa0478dcdfc33d228da3dc4f6c0e82d21ad79bb55e6121ea77840c098597
Source Schema Version 1.1

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